Purchase a kit from the Schematix Store: Click here

Programming and wiring guides:

Download the programming guide: click here

Download the wiring guide: click here

Specifications of the Smart Coffee board:

Power in: 100~240VAC

On board DC power supply: 5VDC, 2A

On board 3.3V power supply: 1A

On board, Solid-Sate relays 100~240VAC live outputs:

2x Boiler element (10A)

1x Pump (10A)

2x Programmable relays (usually connected to solenoid valves) (1A)

Total combined output current limit from relays: 20A

Element 1, and Pump combined max current: 10A

Element 2, RLY1, and RL2 combined max current: 10A

7x 5VDC relay control outputs: (used to control external relays for high current loads)

2x Boiler element

1x Pump

4x Programable relays

Fuse:

2x 5x20mm, 10A

ESP32:

Model: 30pin Development Board

Quantity required: 2

Purchasing link: https://s.click.aliexpress.com/e/_DFc08KN

Inputs/Outputs:

• 4/6 wire Load Cell Input

• I2C display screen interface

• 2x Pressure transducer inputs

• 2x Boiler water level detection probes

• Brew Switch input

• Espresso mode selection input

• Reservoir water level detection options:

Reservoir touch-sensitive probe (for detecting water)

Reservoir float switch (compatible with NO and NC switches)

Ultrasonic water level detection

• Ultrasonic distance sensor (for measuring water level inside a reservoir tank)

• 2x MAX31865 temperature sensors (compatible with 2, 3, and 4 wire probes. PT100 and PT1000 series compatible)

• 6x User programable GPIO pins (M1, M2, S1, S2, S3, and PT3) write your own code to make use of these pins to really customize your coffee experience

• 7x 5VDC relay control outputs: (used to control external relays for high current loads)

• 2x Boiler element

• 1x Pump

• 4x Programable relays

Smart Coffee Software Features:

• Single and Dual boiler compatible with a single group head

• PID and PWM logic boiler control

• Boiler target can be programmed as Temperature or Pressure

• Boiler water level probes (used to trigger a refill when required)

• Display metric units (kPa, Celsius, grams, mls) or imperial units (PSI, Fahrenheit, Ounces, fluid ounces)

• Pre-Infusion cycle for every coffee extraction (3 stages consisting of: Prime the system > Cycle pump on/off > Extract coffee until the programmed amount has been dispensed)

• Momentary or latching switch compatible for Brew and Espresso mode switches

• Pressure transducer inputs to control/monitor pressure

• Programmable pressure safety limits (machines shuts down when safety limits are exceeded)

• Thermocouple temperature sensors to monitor any temperature on the machine

• Programmable pressure safety limits (machines shuts down when safety limits are exceeded)

• Espresso shot output (when espresso mode is activated by the user)

1. • Espresso shot timer
   • Espresso shot by weight target (requires loadcell)
   • Espresso shot by volume target (requires flow meter)

• Pause boiler refill (pauses a boiler refill if an espresso extraction is currently taking place)

• Ultrasonic distance sensor (used for machines with a reservoir tank to measure the water level)

• Reservoir empty standby mode (prevents the machine from operating until the reservoir is refilled)

Purchase Sensors and Hardware:

ESP32:

Model: 30pin Development Board

Quantity required: 2

Purchasing link: https://s.click.aliexpress.com/e/_DFc08KN

Pressure transducer:

Max voltage input from pressure transducer: 5V

Recommended signal range: 0.5 to 4.5V

Recommended pressure rating: 200 kPa (0.2mPa)

(pressure rating should be at minimum 20% higher than your running pressure)

Purchasing link: https://s.click.aliexpress.com/e/_DkQsvxd

Optional G1/4 to 1/4BSP thread adapter (select type 2): https://s.click.aliexpress.com/e/_DdueKDl

Right angle adapter: https://s.click.aliexpress.com/e/_DE8J34X

Display screen:

Model: OLED SH1107

Interface: I2C

Pixels: 128x128

Input power: 5V

Purchasing link: https://s.click.aliexpress.com/e/_DlH1C43

Load cell:

Weight rating: 1kg

Wiring: 4wire

Purchasing link: https://s.click.aliexpress.com/e/_DdDwihl

4 Pin pogo connector:

Purchasing link: https://s.click.aliexpress.com/e/_DB2fN7N

Small size flow meter:

Model: USN-HS06P

Voltage: 5V

Barb Size: 5mm OD

Flow range: 30 ~ 150ml/min

Purchasing link: https://s.click.aliexpress.com/e/_DCCjQh5

Medium-size flow meter:

Model: USN-HS06PS

Voltage: 5V

Barb size: 7mm OD

Flow range: 0.1 ~ 1.5L/min

Purchasing link: https://s.click.aliexpress.com/e/_DFVTRbV

High-pressure Gicar flow meter:

Purchasing link: https://s.click.aliexpress.com/e/_Dlr1vgB

Thermocouple:

Compatible wiring: 2/3/4 wire

Type: PT100 and PT1000 compatible

Purchasing link for screw mount type: https://s.click.aliexpress.com/e/_DkV2nuB

Purchasing link for threaded mount type: https://s.click.aliexpress.com/e/_DD0nYYx

Ultrasonic Distance Sensor:

Model: A02YY

Output signal: PWM

Input: 5V

Purchasing link: https://s.click.aliexpress.com/e/_DFYOL3z

Switches:

Chrome LED lit momentary switch: https://s.click.aliexpress.com/e/_Dd0BleB

(can be used for the brew and espresso mode switches)

USB panel mount connector:

Purchasing link: https://s.click.aliexpress.com/e/_DksmHhh

Shielded multi-core cable:

28AWG, 2meter

Purchasing link: https://s.click.aliexpress.com/e/_DkdDW87

M3 Brass standoff:

These are handy for mounting the PCB

Purchasing link: https://s.click.aliexpress.com/e/_Dn3mUKB

Bug reporting and suggestions:

If you happen to find a bug in the software. Please write a comment below and describe the issue with as much detail as possible.

Updates for Smart Coffee:

Change log and updates:

• V1.0 Base version published
• v1.1 Added Shot Stopwatch feature to time the duration of brewing

PCB Dimensions:

Width: 101mm (3.97")

Length: 166mm (6.53")

Mounting hole size: 3.7mm

https://www.youtube.com/watch?v=4V0a9dfkx9Q&pp=ygUWc21hcnQgY29mZmVlIHNjaGVtYXRpeA%3D%3D

Buy Smart Coffee for Arduino Mega here

PLEASE NOTE:

The latest version of Smart-Coffee for ESP32 can be found here: Click here

Smart - Coffee: Arduino Mega Version is highly customizable software that runs on an Arduino or similar microcontroller to control the various functions of an espresso machine.

The software can be configured to replace the factory controller functions such as:

• Control the boiler pressure using programmable PID or PWM logic

• Check the boiler water level through the factory-fitted probe

• Refill the boiler by activating the pump and refill valve

• If a water reservoir tank is present, it can check the water level using a probe OR via a switch. If the reservoir is empty, the element and pump will be disabled until the reservoir is refilled

In addition, the software can add extra features such as

• OLED display that can show pressure, temperature, water tank level, mode, pump & element icons, and more in both metric or imperial units

• Pre-infusion cycle what can be customized to pre-infuse the coffee grounds at low pressure before extracting the shot (activated when Espresso mode is ON)

• Espresso Mode, which can be customized to stop the pump after a programmable amount of water is dispensed.

• Flow meter that can keep track of how much water has been dispensed

• Espresso timer that automatically stops the pump after a programmed amount of time

• Water reservoir level can be measured using an ultrasonic sensor and printed on the display. No more manually checking to see if you need to refill the reservoir tank!

• Pause a boiler refill from happening when an espresso shot is being made

• Temp sensor that can be used to measure any temperature on the machine

• Safe mode ,which can be programmed to shut down in the event the pressure and/or temperature exceed the programmed limits

Buy Smart Coffee for Arduino Mega here

Download a preview version of Smart Coffee software here

(The preview version allows you to view the Setup and Guide pages before purchasing)

Watch the video to learn more about smart coffee here

Video Playlist for configuring Smart Coffee here

https://www.youtube.com/watch?v=xLFKHLZmIQU

https://www.youtube.com/watch?v=E3XvC9OBd6Y

https://www.youtube.com/watch?v=_TEz-tKsQaw

https://www.youtube.com/watch?v=IY6pxvH7DUA

Espresso Machine Compatibility:

Smart Coffee should be compatible with most single-boiler (aka heat-exchange) machines that have the following hardware:

• Water Pump

• Solenoid valve (to refill boiler)

• Heating element

• Boiler water level probe

• Brewing switch

If your espresso machine uses a currently unsupported hardware configuration, you can submit a request below to have your hardware configuration supported with a future update.

UPDATES to Smart Coffee:

V2.0

• First Released Version

V2.1

• Added the option to use temperature as the target for the boiler element control.

• Added the option to disable pressure safety limits.

• Added the option to disable the pressure transducer.

• Renamed "TEMPERATURE_SAFETY_FEATURE_ENABLE" to "TEMPERATURE_SAFETY_LIMITS_ENABLE"

v2.2

• Refined and optimized logic

• Updated pressure reading units to display 0.0 resolution

• Changed printed display value "Kpa" to "kPa"

• Added multiple attempts to connect to max31865 temp sensor

• Updated serial printing logic

• Removed obsolete serial printing commands inside the brewing logic

DOWNLOADS:

• Download STL files to print the SH1107 display mount here

• Download the wiring diagram here

• Download a preview version of Smart Coffee software here

(The preview version allows you to view the Setup and Guide pages before purchasing)

WIRING DIAGRAM:

Adafruit MAX31865 board configuration: https://learn.adafruit.com/adafruit-max31865-rtd-pt100-amplifier/rtd-wiring-config

FAQs:

Will there be updates for Smart Coffee? We've reached the limits of the Arduino Mega platform, and thus moved to an ESP32-based platform, which allowed for even more options. The mega version will still be supported; however, further development will be made on the ESP32 platform. 

My machine has a different hardware configuration, will Smart Coffee support it in the future? One of our goals is to have Smart Coffee be highly compatible with most espresso machines.  If your espresso machine uses an unsupported hardware configuration, you can submit a request to have your hardware configuration supported with a future update.

Do you offer technical support? No, we do not offer individuals technical support for installing Smart Coffee. Our videos, guides, information, and software are supplied for educational purposes only.

Are there any warranties given or implied? No. Smart Coffee software is supplied for educational purposes only.

Are future updates free to download if I purchase Smart Coffee? Yes, once you buy Smart Coffee software, future updates will be free to download. As the project evolves over time, there may be variants of Smart Coffee, for example, ‘Smart Coffee – Dual Boiler edition’ which may require a separate purchase.

Hardware list:

(affiliated links, thanks for your support)

Pressure transducer: https://s.click.aliexpress.com/e/_DD26P6x

• Input: 5V

• Sensor output: 0.5 ~ 4.5V

• Pressure range: 0 ~ 0.4Mpa (400Kpa)

• Thread: G1/4 (aka ¼” BSPP)

• (thread adapter may be required to fit different machines)

¼” BSP to G1/4 adapter: https://s.click.aliexpress.com/e/_DmjM9T5

Right angle adapter: https://s.click.aliexpress.com/e/_DCGZhH5

Arduino MEGA 2560 PRO: https://s.click.aliexpress.com/e/_DEqZP9t

OLED display: https://s.click.aliexpress.com/e/_DlNwzh1

• OLED SH1107 display

• Interface: I2C

• Pixels: 128x128

• Input: 5V

Ultrasonic Ranging Sensor: https://s.click.aliexpress.com/e/_DdEwlEb

• Model: A02YY

• Output signal: PWM

• Input: 5V

(Solid state relays with appropriate current and voltage ratings for the pump, refill valve, and element)

2 Channel SSR: https://s.click.aliexpress.com/e/_DEuadS3

• Control: 5V Low-level logic (aka GND pin to turn relay ON)

• Load current: 2A

• Load voltage: 250VAC

40A Solid state relay: https://s.click.aliexpress.com/e/_DkRF9Ij

• Control: 3 ~ 32VDC

• Load current: 40A

• Load voltage: 24~480VAC

   

MAX31865 temp sensor with probe:  https://s.click.aliexpress.com/e/_DefQQLp

Adafruit MAX31865 board configuration: https://learn.adafruit.com/adafruit-max31865-rtd-pt100-amplifier/rtd-wiring-config

Small size flow meter: https://s.click.aliexpress.com/e/_DFDQ3vv

• Model: USN-HS06P

• 5 ~ 12V

• 6mm OD

• 30 ~ 150ml/min

Medium size flow meter: https://s.click.aliexpress.com/e/_Dl8u7QT

• Model: USN-HS06PS

• 5V

• 6mm OD

• 0.1 ~ 1.5L/min

(For a high-pressure flow meter, google search for “GICAR flowmeter” or similar)

Chrome on/off Switch: https://s.click.aliexpress.com/e/_DdqG6h9

Micro USB panel mount: https://s.click.aliexpress.com/e/_DBQWf5h

5V PSU: https://s.click.aliexpress.com/e/_DBJgyX1

• Model: MeanWell - RS-15-5

• Output: 5VDC, 3A

Miscellaneous:

2mm Clear acrylic sheet (for OLED display mount): https://s.click.aliexpress.com/e/_DDmUUlh

(Display mount acrylic screen size: 2x38x50mm)

Connectors: https://s.click.aliexpress.com/e/_DdGNokf

(I used 2x 4pin connectors in my build, however this assorted pack comes in handy)

Plastic enclosure: https://s.click.aliexpress.com/e/_DD9Nslv

(Purchase an enclose that has sufficient space for the electronics you're using and fits inside your machine)

Shielded multi-core cable: https://s.click.aliexpress.com/e/_DmRkGGd

(26AWG, 10core shielded cable)

Dupont crimping tool: https://s.click.aliexpress.com/e/_DkR40YX

Rivet nut tool: https://s.click.aliexpress.com/e/_DE05vaf

Please make sure to read all information under the "Notes:" header, before you attempt to build this buck converter :)

Specifications:

Minimum input voltage: 8v

Maximum input voltage: 40v

Minimum output voltage: 1.25v

Maximum output voltage: 36v

Maximum output current: 8A

Output voltage ripple, 32v input, 12v output with 8A load: <100mvpp

XL4016 features:

High efficiency up to 96%

Built-in thermal shutdown function

Built-in current limit function

Built-in output short protection function

Built-in input over-voltage protection

PCB Gerber files download:

https://drive.google.com/open?id=1eVJ_HyIm6lQEcE5Cmfargr02WNg8vWhP

PCB measures: 66x59mm

Mounting hole pitch: 58x52mm

Schematic:

Bill of materials:

1x Schematix XL Buckconverter v1.4 PCB

2x 2way screw terminal: P5.08mm (J1, J2)

3x 470uF 50v capacitor: D12.5mm P5.00mm (C1, C7, C8) (See notes)

6x 1uF Ceramic Disk capacitor: P5.08mm (C2, C3, C4, C5, C6, C9)

1x XL4016E1 buck IC: TO220-5L (U1)

1x MBR1545CT Dual Schottky diode: TO220 (D1)

1x 47uH 10~12A Inductor: L31.8mm W15.9mm P13.50mm (See notes)

2x 1/2w 360R resistor: L6.2mm D2.5mm (R1, R2)

1x 10k ohm 25 turn trimmer (model: 3296W) (RV1)

2x Extruded heatsink, TO220 compatible, P25.4 mm W35mm D12.7mm (See notes)

Notes:

Electrolytic capacitors C1, C7, C8 should have low ESR & ESL values & be suitable for use in switch-mode power supplies (for example the Nichicon UPW1H471MHD1TO)

Inductor L1 is a toroid style inductor who’s core material should be ‘powdered iron’ for optimal performance. I recommend the “Bel HCTI-47-10.7” inductor for this application

Heatsink: The recommended heatsinks to use is CUI HSE-BX-035H-01.

2 Heatsinks are required. One for the XL buck IC & another for the MBR Schottky diode.

Cooling: Consider adequate ventilation and/or a fan to keep the heatsinks at a reasonable temperature.

In free air with room temperature at 22c, at a full 8amp load the buck IC temp was measured at 116c. While at 4amp load the buck IC temp dropped to 70c. By the use of a fan blowing air over the heatsinks, these temps quickly drop. Personally I'd try to keep temps around 80c or lower.

High current PCB traces. On the underside of the PCB there are exposed traces that carry the high current between the input & output. On their own, these traces would overheat & potentially burn out. To avoid this the high-current traces are exposed (aka no solder mask) allowing the user to tin the traces with solder and thus allowing the traces to easily handle the maximum current the Xl4016 can output.

PCB dimensions: 66x40mm

Hole pitch: 58x33mm

About this circuit:

What is a low volt disconnect? A low volt disconnect is used to prevent batteries from being over-discharged. Since this circuit operates a relay to connect/disconnect a load from a power source. It can also be used to switch between multiple power sources (such as a battery & power supply) which is what I’m using it for in my Dual power fume extractor project.

Keep in mind that when the relay is switched on, the circuit consumes about 60mA. That is not much power unless you plan on running it from a solar panel with a small battery. In which case I’d recommend modifying the circuit to utilize a MOSFET to replace the relay. It would drop power consumption down to around 10mA

I also want to credit the source of inspiration for this circuit Click here

Resistors R2 & R4:

Resistors R2 & R4 determine the Disconnect & Reconnect voltages. Which you can customize anywhere between 3.5v to 24 volts. But how do you go about choosing the correct resistor value?

Pins 2 & 6 of the 555 Timer measure the voltage through a pair of voltage dividers. And if the voltage is high enough, the timer will switch on the relay. And if the voltage drops below a certain value, the timer will switch off the relay.

Pin 2 determines the Disconnect or “Cut off” voltage, and Pin 6 determines the Reconnect voltage.

Let’s focus our attention to Pin 6. When pin 6 has 3.33volts or higher, the relay will switch on.

In order to figure out the correct resistor value for R2. First, you need to choose what voltage you desire the relay to switch on. This can be anywhere from 3.50 to 24 volts

I’ll leave a link to this handy voltage divider calculator which makes it super simple to calculate the resistance value of R2 https://ohmslawcalculator.com/voltage-divider-calculator

1. In the “Voltage Source” box, enter your desired voltage you want the relay to switch on.

2. In the “Resistance 1 (R1)” box, enter the resistance value of R1 (which is 10k ohms)

3. Leave the “Resistance 2 (R2)” box empty

4. Lastly in the “Output Voltage (Vout)” box, enter the desired output voltage (which for Pin 6 of the 555 timer is 3.33volts)

5. Press calculate, and the calculator will now display the required resistance value of R2 in the “Resistance 2 (R2)” box.

Unless you get lucky, most of the time you’ll calculate a random resistance value (Such as 7924 Ohms) and you won’t find a resistor that perfectly matches your calculated value. So just select a resistor with the nearest value.

Before deciding on a disconnect voltage value for your application, it is important to note that this circuit requires a minimum hysteresis of 0.25volts to prevent unwanted oscillation (rapidly switching on & off repeatedly) For example if your Connect voltage is 10.0 volts, then the maximum disconnect voltage would be 9.75 volts. For high current loads that pull-down the source voltage, you may need to substantially increase the hysteresis to prevent unwanted switching.

Now you need to repeat the process for resistor R4.

Pin 2 of the Timer determines the cut off voltage (which switches off the relay). When the voltage on pin 2 drops below 1.66 volts, the relay will switch off

1. In the “Voltage Source” box, enter your desired voltage you want the relay to switch on.

2. In the “Resistance 1 (R1)” box, enter the resistance value of R1 (which is 10k ohms)

3. Leave the “Resistance 2 (R2)” box empty

4. Lastly in the “Output Voltage (Vout)” box, enter the desired output voltage (which for Pin 2 of the 555 timer is 1.66volts)

5. Press calculate, and the calculator will now display the required resistance value of R4 in the “Resistance 2 (R2)” box.

Components:

C1 = 220uF 35v, D8.0mm_P3.50mm

C2, 3 = 10uF 16v D5.0mm_P2.50mm

D1 = 1N4001 THT Diode

D2 = 5mm THT LED (change R5 value to suit your LED's forward current if needed)

J1 = 2way Screw terminal P5.08mm

J2 = 3way Screw terminal P5.08mm

J3 = External LED can be connected to J3 if required

K1 = 5v Sugarcube style relay (Omron G5LE-1 Or Songle SRD-05VDC-SL-C Or similar)

R1, 3 = 10k Ohm, 1/2w, THT resistor

R2, 4 = User to choose value based on desired connect/disconnect voltages

R5 = 1k Ohm, 1/2w, THT resistor

U1 = LM7805 Voltage regulator, TO-220

U2 = NE555P Timer, DIP-8

Complete How-To-Build video: https://youtu.be/doCg0k0m-dA

Description:

This project came about because I wanted to have a cordless fume extractor. The extractor can be powered from either a 12VDC wall adaptor Or 3x 18650 lithium batteries making it rather unique. To prevent the batteries from being over-discharged & to prevent both power sources from competing to drive the fan, a low volt disconnect I build in another video is used. You can learn more about the Low-Volt-Disconnect here.

If both power sources are present, by default the fan will run from the batteries. In an ideal world, I'd prefer the power adaptor to be the default power source. But hey, in reality, I'm only going to use the pwr adaptor as a back up if the batteries run flat.

Selecting a high-performance 140mm fan is very important. The fan I used can be found below under components. However, you could select any other fan with similar performance figures.

For comparison, these are the specs of the Noctua fan I used:

• Airflow: 158.5 CFM

• Static pressure: 10.52 mmH20

How effective is the filtration? That’s a good question. I don’t have specialized equipment to measure the air quality, however, I’m certain it doesn’t filter everything since I can visibly see some smoke exhaust out the back of the extractor.

So does that mean it’s useless? Well not in my opinion. In my workshop, all I had to do was prevent the smoke from concentrating around my immediate work area. And this fume extractor does just that, it sucks away the concentrated smoke and blows it away from my work area.

The housing for this project is entirely 3D printed. And the 3D files can be found here: https://www.thingiverse.com/thing:4597398

3D Print one of each except for the enclosure files. You only need to print a single enclosure and you must choose one that suits your power switch size, there are 16mm, 19mm & 22mm variants and there is also the option to print an enclosure that doesn't have any switch or DC power jack holes. This way you can print the enclosure and dill/cut holes to suit your hardware.

If you purchase any products using the affiliate links below, you are helping support my content and that makes you awesome! 😎

Components:

• Noctua Industrial 140mm Fan, 3000rpm: https://amzn.to/3mv9R0r

• Carbon filter sheet (cut down to 138x138mm): https://amzn.to/2Flp837

• 3S 18650 battery compartment: https://ebay.to/3hxUXCA

• 16mm DPST On/Off switch: https://ebay.to/3kjVhHa

• 5.5x2.5mm DC power jack, female, panel mount: https://ebay.to/3c13ywC

• SB540 Schottky diode: https://ebay.to/3mwWvke

• Low volt disconnect: https://www.schematix.co.nz/forum/how-to-s/low-volt-disconnect-project

Optional: 12VDC, 1A wall adaptor: https://amzn.to/3c1maN1

Hardware:

8x 4g 12mm countersunk, self-tapping screw (used to assemble the enclosure)

4x M4x40mm countersunk, screw (used to mount fan)

4x M4 nyloc nuts (used to mount fan)

4x 4g x 6mm pan head screws (Mount LVD to enclosure)

4x PC fan screw (secures the battery compartment to enclosure cover)

Wiring Diagram:

 

Resources:

Build & demo video: Click here

Coil form tool Download STL file

PCB Gerber files Download gerbers

Schematic Download Schematic

Details:

Voltage input: 12~48VDC

Current input: up to 30A (@48VDC)

Peak power input: 1,400watts

The Circuit

This induction heater is based on the popular "Royer induction heater" schematic. I believe this is the original post/author? Click here

Changes made to the design include:

• Higher rated MOSFETs

• Bigger Zener diodes

• RC filter on the Gates

• Flyback Diode (D8)

• Gate resistors to limit ringing (R8, R9)

In short, all of the changes help to improve the durability of the induction heater. It has been reported with the original design, often the MOSFET gate's would be damaged from flyback after extended use. To be fair, I haven't tested the circuit without my additions so I can't confirm or deny this. Gate resistors have to be added as ringing was quite a problem without them. The ringing would cause the MOSFETs to become quite hot & this can lead to premature failure. With the addition of a pair of 18R gate resistors. The ringing was reduced to an acceptable level.

Components:

2x Wakefield-Vette, 694-50 Heatsink Click here

2x IRFP4668PBF MOSFETs Click Here

10x WIMA, MKP1J034706B00KB00, 470nF, 630VAC Capacitor Click here

2x 2.2uF Ceramic 100v Capacitor Click here

2x FR307 Fast Diode Click here

2x 47R, 5w Metal Oxide resistor Click here

2x 470R, 5w Metal Oxide resistor Click here

2x 12v, 5w Zener Diode Click here

1x SB5H100 Schottky Diode Click here

2x 100uH, 15A inductor Click here (see below for details)

2x 10k, 1/2w resistor

1x 4.7k, 1/2w resistor

2x 18ohm 1/2w resistor

1x 5mm LED of your choice (power indicator LED)

The inductors

For the inductors, I opted to wind my own. Options for this size are somewhat limited & it was cheaper to make my own anyhow. If you don't wish to make your own, then alternatively you can buy them from banggood Click here

Toroid details:

Size: 42x22x17mm

Material: Iron Powder, HY2

Color Code: Yellow/White

For the wire, I used 1.25mm (16AWG) enamel insulated copper wire. Each toroid used approx 1.6m (63inch) of wire. This length of wire yields 30~32 turns around the toroid giving an approx inductance of 100uH.

Tinning the high current traces

Located on the underside of the PCB is several exposed traces that should be tinned with PLENTY of solder after all the components have been installed. These traces carry very high current that pulses through the work coil. Failure to adequately bolster these traces with copious amounts of solder will result in the solder melting off the PCB, which will result in the trace burning out, which in turn blows up one of the MOSFETs (not that I'd have done anything like that :P )

I'd recommend laying down some fairly heavy copper wire on top of the traces & solder it in place just to be on the safe side.

The Coil

This is the work coil. I made my coil from 3/8" copper tubing (the type used for aircon, fridges.etc) It's pretty inexpensive & easy to find at most hardware stores or aircon shops. The inside diameter of my coil is 70mm to accommodate almost anything I'd need to heat.

The coils consist of 6 & 1/2 turns. The amount of turns does play a role in determining the resonating frequency (and also power output/consumption). If you know what you are doing & are willing to experiment with different coils, then go for it. Otherwise, I'd suggest making a coil with 6~8 turns.

If you watched my build video, then you'll have seen me 3D print a form tool, used to wrap the copper around to form the coil into a spiral. Strictly speaking, It's not essential however, it does produce a nice uniform coil. You can download the STL file Here

Performance

With a 48V power input and a 140mm PC fan blowing air over the heatsinks & caps. Temperatures were quite acceptable at 80c (176f) for the MOSFETs, the capacitors were about the same. And the inductors never felt even slightly warm. I think for higher input voltages (above 48VDC) You'd have to start considering spacing the caps further apart for better cooling & depending on how far you push the envelope.... maybe water cooling the MOSFETs & work coil.

Will it melt Aluminum?

The original author demonstrates his induction heater melting an aluminum heatsink. I've attempted to melt alloy in my induction heater and it failed to do so. I'm not exactly sure why he was able to melt alloy and I was not but, I do wonder if he is tuning up his power input to achieve this? He seems to indicate this in his post. It's also possible different alloy's melt easier than others so perhaps this is something I'll explore later.

What would it take to make this induction heater more powerful?

In truth, the components used could probably handle 60V (just monitor the peak voltage across the caps & make sure to stay within their max voltage rating). However, at higher power levels, you certainly need to bolster the high current traces on the PCB to prevent failure. Keeping the caps & MOSFETs within temperate limits could also be a challenge. Perhaps water-cooling would be a viable solution? In any case, it's certainly possible for this circuit to handle higher voltage than 48VDC if appropriate measures are implemented.

WARNING!

This induction heater produces hundreds of volts across its output. DO NOT touch the circuit OR workcoil while powered on! Or you risk being electrocuted! Once the power is switched off, the capacitor bank instantly discharges and the circuit is safe to work on.

Downloads:

Circuit Schematic

PCB Gerber Files

Watch Build Video

Specifications:

PCB Size: 86 x 284mm

Input voltage: 40~65VDC

Max input current: 50A

Max power consumption: 3,250watts

Assembling the PCB

You’ll find all the components & their specifications listed below. You can download a detailed schematic to identify what component goes where on the PCB.

PCB Components:

C1~14 – 330nF 600VAC Capacitors

C15, C16 – 2.2uF 100V Ceramic Capacitors

D1, D2 - 12V 5W Zener Diode

D3, D4 – FR307 Fast Diode

D5 – 5mm LED

D6 - SB5H100 200A 100V Schottky Diode

L1, L2 – 60uH 25A Custom made inductors (watch video)

R1, R3 – 150R 5W Metal Oxide Resistor

R2, R4 – 1K 5W Metal Oxide Resistor

R5, R6 – 10K 1/2W Metal Oxide Resistor

R7 – 4.7K 1/2W Metal Oxide Resistor

R8, R9, R10, R11 – 18R 1/2W Metal Oxide Resistor

Q1, Q2, Q3, Q4 - IRFP4668PBF MOSFET

Bolstering the PCB traces

The traces on the PCB that are exposed on the underside need to be bolstered by either cutting out copper busbars from a sheet of copper (1.5mm or thicker) Or by using 14AWG, 2.5mm core electrical cable, soldered to the PCB traces. I used the latter method in the build video, and although it’s not very aesthetically pleasing. It’s proven to work without any issues

Workcoil Design

• The workcoil is the business end of all induction heaters. When it comes to designing a workcoil several design elements should be taken into account. This is an area where I’d admit, I’m still learning myself, so I don’t consider my advice on this topic to be all that helpful. But, a good starting point is to have a workcoil with 6 turns of 3/8” copper tubing to make the workcoil.

• The internal diameter should be around 10~20mm larger than the piece of metal you’re intending to heat.

• Using a workcoil that has a much larger diameter than the piece of metal you’re heating, will reduce performance & lead to longer heat times.

• The air gap between turns has a significant role in determining the input current consumption and power output. Increasing the air gap also increases input current consumption. And the opposite is also true, smaller airgap = lower input current consumption. Calculating the correct air gap on paper before you construct your workcoil is very doable however, it's also possible to use a trial & error method. Start by keeping the windings tight (around 2mm air gap), operate the induction heater, and monitor the current consumption, if you wish to increase the current, then gently spread the winding further apart to increase the airgap. You can repeat this process until you achieve your ideal power input/output. (Don't forget to have the induction heater OFF while making alterations to the workcoil)

A company called ‘Ambrell’ published a 28-page guide on workcoil design. You can request a free copy of their guide by using this link Click Here (They do ask for your name & email, but it’s 100% free)

Cooling

During normal operation, the MOSFET heatsinks & capacitors will get hot! You will need to use a fan to blow air over the components to keep the temperatures at acceptable levels.

For runtime more than 30 secs or so, the workcoil will get very hot. I’d highly recommend cooling the workcoil by continually pumping water through it.

Printed Circuit Board

Order your own custom printed circuit board using the files below:

Download PCB Gerber Files

Inductors

I made my own custom inductors for this project. I used a total of 4x T157-26 Inductor Toroid Rings. Each inductor has 2 toroid rings stacked on top of one another. I have found this to be the most cost-effective solution for this project. A total of 16 turns of 2mm (12AWG) magnet wire is wrapped around the toroids to produce an inductor with approximately 60uH of inductance.

You can customize the inductance by adding or subtracting turns around the toroids. If you’re heating smaller pieces of metal, to maximize power output from the induction heater into the piece of metal you’re heating, you may want to consider lowering the inductance to around 30~40uH. Similarly, the inverse is true. If you’re heating large pieces of metal & your induction heater is drawing more current than the maximum allowed (50A) Then increasing the inductance to 60~200uH will bring the input current down to a safe level.

If you’re using 2x T157-26 stacked together, below is a cheat sheet to quickly customize the inductance.

Number of turns for inductance:

36uH = 13 Turns

60uH = 16 Turns

100uH = 21 Turns

150uH = 26 Turns

200uH = 30 Turns

Alternatively, you can use this calculator to help you customize the inductance

Components:

4x T157-26 Inductor Toroid Ring

· Size: 40x24x15mm

· Material: Iron Powder

· Magnetic Permeability: 75

4x Wakefield-Vette 694-5 MOSFET Heatsink

· Size: L:50 W:22 H: 35mm

· To fit: TO-247 package

14x WIMA MKP1O133306F00KSSD 330nF 600VAC Capacitors

· Size: L: 31.5 W: 15 H: 26mm

· Lead Spacing: 27.5mm

· Voltage: 600VAC, 1000VDC

· Capacitance: 330nF

2x TDK FG20X7R2A225KRT06 2.2uF 100V Ceramic Capacitors

· Size: L:7 W: 5.5 H: 4mm

· Lead Spacing: 5mm

· Voltage: 100VDC

· Capacitance: 2.2uF

2x ON Semiconductor 1N5349BRLG 12V 5W Zener Diode

· Package: 017AA-2

· Power: 5W

· Zener Voltage: 12V

2x Rectron FR307-B Fast Diode

· Package: DO-201AD

· Voltage: 1000V

· Current: 3A

· Type: Fast recovery 500ns

1x 5mm LED

· Forward Current: 20ma

· Regular Through hole 5mm LED

· Color of your choosing

1x Vishay SB5H100-E3/54 Schottky Diode

· Package: DO-201AD

· Voltage: 100V

· Surge current: 200A

2x 150R 5W Metal Oxide Resistor

· Size: L: 17.5 D: 6.5mm

· Power: 5W

2x 1K 5W Metal Oxide Resistor

· Size: L: 17.5 D: 6.5mm

· Power: 5W

2x 10K 1/2W Metal Oxide Resistor

· Size: L: 6.5 D: 2.5mm

· Power: 1/2W

1x 4.7K 1/2W Metal Oxide Resistor

· Size: L: 6.5 D: 2.5mm

· Power: 1/2W

4x 18R 1/2W Metal Oxide Resistor

· Size: L: 6.5 D: 2.5mm

· Power: 1/2W

4x IRFP4668PBF MOSFET

· Package: TO-247-3

· N-Channel MOSFET

· Vds: 200V

· Id: 130A

· Rds On Resistance: 9.7mOhms

Other Components & hardware:

· 3.2meters (11ft) of 2.0mm (12AWG) Magnet Wire (aka ‘enamel copper wire’) for winding the inductors

· 2~3 meters of 3/8” Copper Tubing to make workcoil

· 2mm (14 Gauge) thick Copper sheet to cut into PCB busbars OR 2.5mm core electrical cable to solder to PCB traces

Complete list of all the mods I've done to my B1 printer including adding a BL Touch sensor, Fitting E3D Hemera Hotend, Adding an additional Z-axis stepper motor, X Y Z Cable drag chains & spool holder with filament guide.

Warning! Modifying 3D printers can be difficult depending on the modification you're attempting. Along with your knowledge on the subject. If you choose to replicate anything you've seen me do to my printer, you assume all the responsibility for any damage caused to the printer or otherwise.

Firmware

• BIQU B1 - BL Touch enabled Firmware (Marlin v2.0.7): https://drive.google.com/file/d/1hA0YWWLuBLSxj6hug5vP0etp5dLGwlDv/view?usp=sharing

• BIQU B1 - Default firmware (Marlin v2.0.6): https://drive.google.com/file/d/1lngKTn-ftTjN0HLZmiKRmH5iiLiPfFy-/view?usp=sharing

Compiling / Editing Marlin

To edit the Marlin firmware I use Visual Studio Code by Microsoft. To read & compile the firmware, I used "PlatformIO IDE" and "Auto Build Marlin" extensions inside VSC. It's free to download and use: https://code.visualstudio.com/download

Hemera Hotend Firmware settings:

If you choose replicate the X-Carriage plate with a Hemera hotend, BLtouch sensor & Blower fan. Here are the settings I changed in Marlin (changes are in RED text)

Uncomment: #define USE_PROBE_FOR_Z_HOMING

Uncomment: #define Z_SAFE_HOMING

#define TEMP_SENSOR_0 5

#define HEATER_0_MAXTEMP 300

#define DEFAULT_AXIS_STEPS_PER_UNIT { 80, 80, 400, 409 }

#define DEFAULT_MAX_FEEDRATE { 150, 150, 5, 5 }

#define NOZZLE_TO_PROBE_OFFSET { 0, -47.0, -3.0 }

#define Y_BED_SIZE 223

Don't forget to perform a temperature cycle on the hotend to determine the correct Ki, Kp & Kd values. More info on this topic is available here: https://reprap.org/wiki/PID_Tuning

3D Printed Parts

• Fan Duct STL files: https://www.thingiverse.com/thing:4871426

• Z-Axis & Drag chain STL files: https://www.thingiverse.com/thing:4871442

X Carriage Cutting template:

Download: https://drive.google.com/file/d/1twM5uDEOIBM7zax33n63OV89b6FBANLz/view?usp=sharing

Wiring Diagram:

Download: https://drive.google.com/file/d/1--AL5Ga6xZP1AtZEMo7D6fkkTosJenhW/view?usp=sharing

Hardware List:

ANTCLABS Bltouch Sensor (be aware of counterfeits/clones): https://amzn.to/3oZmXUY

E3D Hemera 24V hotend kit: https://e3d-online.com/products/e3d-hemera-direct-kit-1-75mm

JST Connector kit (used to wire up everything to the control board): https://amzn.to/3oWhyhH

X-Carriage with Hemera Hotend mod

• 1meter of GT2 Driver belt

• 5015 Blower Fan 24Volt (Part cooling fan)

• 3x M5x6mm spacer (Spaces the Hemera away from the X carriage plate)

• 380mm long 20x20 V-slot rail

• 3x M3x12mm (Mounts Hemera)

• 3x M5x26mm (Mounts V-wheels)

• 1x M4x12mm + M4 nut(Limit switch bump stop)

• 1x M5x8mm Countersunk (Mounts limit switch bracket)

• 2x M3x10mm (mounts limit switch to bracket)

• 2x M3 Knurled inserts (mounts limit switch)

Z-Axis Motor mod

• 400mm 8mm lead screw + nut

• 3x M5x6mm spacer (Spaces the mount away from the v-wheels)

• 2x 5x8mm Coupler (Nema motor to lead screw coupler)

• 3x M5x36mm (lead screw nut mount)

• 4x M3x12mm (Nema motor)

• 2x M5x20mm (Mounts nema motor bracket to Z axis rail)

• 2x M5x12mm + nuts (Mounts nema motor bracket to chassis)

Drag Chain mod

• 8x M3x10mm + nuts (Connects drag chains to mounts)

• 2x M3x12mm (X Z Axis drag chain mount)

• 2x M3x8mm (X Carriage drag chain mount)

• 3x M5x12mm + nuts (Y Z Axis Chassis drag chain mount)

• 1x M5x12mm + nut (Y Axis Bed drag chain mount)

•  

• 540mm long, 10x10mm R28 Drag chain (X Axis)

• 340mm long, 10x20mm R28 Drag chain (Y axis)

• 730mm long, 10x20mm R28 Drag chain (Z axis)

Spool Holder mod

• Quick change spool holder: https://www.thingiverse.com/thing:1241566

• 150mm 20x20mm V-slot rail

• 2x 608zz bearings

• 2x V-Slot right angle brackets

• 5x M5 V-slot rail nuts

• 5x M5x8mm

• M8 threaded rod

• 4x M8 washer

• 3x M8 Nyloc nuts

• 4mm Pneumatic push fitting

• 1m of 4mm O.D tubing (filament guide)

• 240mm long 25x3mm alloy flat bar

(Hidden TV lift cabinet)

(Geometric shape padded headboard)

(Queen size slatted bed base)

About this bed set:

This bed set is designed to fit a standard Queen size mattress (1530x2030mm). The bed base has been designed to leave an 80mm gap between the end of the mattress and TV cabinet. This leaves enough room to easily make the bed & still have room for blankets.etc.

The lift mechanism can accommodate large TVs. The cabinet I build comfortably fits my 55" TV with a soundbar under the TV that measures 80mm in height. Larger TVs up to 70" should be possible if some additional height is added to the TV cabinet to provide sufficient clearance for the lid to close.

Scroll down for detailed drawings with dimensions...

Full build video: https://youtu.be/yUhPvJVxkQc?si=wqAxPLPv_KikkLqJ

TV lift mechanism (affiliate link): https://s.click.aliexpress.com/e/_oBTc9Y1

Materials:

TV lift cabinet:

TV lift mechanism: 710-1610mm 45-70inch TV

Framing timber: 22 meters of 70x35mm

2x 12x1200x2700mm plywood sheets

Needle punch wadding

Upholstery fabric

Bed base:

Bed base framing: 20 meters of 90x45mm timber

2x Bed base side panels: 20x140x2180mm

12x 20x90x1540mm bed slats

Needle punch wadding

Upholstery fabric

Headboard:

2x 12x1200x2400mm plywood sheets

2x 20x90x1100mm slats

50mm thick foam padding

Needle punch wadding

Upholstery fabric

MISC materials:

HDPE plastic strip

Cable drag chain, 10x10mm R28, 1 meter long

Panio style hinge

3x50mm Alloy flat bar

Chain (for cabinet lid)

Spray contact adhesive

Felt (for legs)

PLEASE NOTE, there is the potential to brick your motor controller during flashing if you do not follow the manufacturer's instructions. This guide is intended to help you understand the process however it's provided on an as-is-where-is basis.

Motor programming software:

The software I used to program my Bafang motor is a modified version by Penoff. You can download his excellent programming software from his page or alternatively download it here

USB COM port drivers:

You may need to install the appropriate USB serial drivers in order to successfully connect to the USB programming cable. Depending on the model of cable purchased, you may need to download and install USB serial drivers. I’ve included the 2 most common driver types below; use whatever is recommended by the seller of your specific cable.

CP210 Download

CH341 Download

Connecting the cable:

1. Switch off the battery of your e-bike

2. Unplug the display cable (as shown below)

3. Connect the programming cable to the display cable (as shown below)

4.Turn on the battery of your e-bike (as shown below)

5. Plug in the programming cable to your PC

Before programming:

Before you change any settings, I highly recommend you backup the default settings. That way if you have a backup if something goes wrong with your settings

1. Select the COM port that your USB programming cable is connected to. Hitting the magnifying glass will automatically select the correct port.

2. Now click ”Connect”

3. Now click “Read flash” in the right bottom corner of the program.

4. You should now see all your settings.

5. Click ”File” in the left top corner of the program.

6. Click ”save as” and save your file at a location that you can access later if necessary.

7. You now have created a backup you can use later if problems occur.

Programming:

At first glance, the programming may be a little intimidating using a bunch of convoluted words that you may be confused by at first glance. Fortunately, I found the article at EDRIVENET most helpful in describing the function of each setting.

First, start the programming software and select the COM port that your USB programming cable is connected to. Hitting the magnifying glass will automatically select the correct port.

Now click ”Connect”

Now click “Read flash” in the right bottom corner of the program.

You should now see all your settings.

Basic tab

Pedal Assitance tab

Here are my preferred settings

Basic tab:

Pedal assist tab

Low Battery Protection = Once the battery reaches this voltage, it will stop any further discharge to protect the battery

Current Limit = This value (measured in Amps) sets the maximum current the motor can draw from the battery. To comply with local laws in New Zealand, when using the bike on public roads, I set the current limit at 5.7 which keeps the maximum power output below the legal 300watts (5.7A x 52V = 296.4watts peak power) However, you can set this according to your needs (just don't exceed the current you motor controller is rated for)

Assist levels 0~9 = Each assist profile can be programmed to give the rider a percentage of the maximum current limit & speed limit (you can cycle through each profile by using the + or – button on the handlebar-mounted controller). I experimented with setting different speed limits in each profile but I found it to be quite annoying and overly complicated. To simplify my riding experience, my preferred setup is to set all the profile's speed limits to 100%. Then all you have to do is decide what percentage of the current limit you assign to each profile. I opted to have each profile setup in 10% increments (for example Profile 1 is 10%, profile 2 is 20% and so on) but you could simplify it further by setting the first 4 profiles at 25%, 50%, 75% and 100%

(My preferred setup pictured below)

Speed Meter Type: External, Wheel Meter

This is the only speed sensor that works with the Bafang BBSxx, this setting is the default. So don’t change it unless you know what you are doing

Speed Meter Signal: 1

The only setting that works is 1, again default. Don’t change it unless you know what you are doing

Wheel Diameter :

Set this setting to match your wheel diameter.

Pedal Sensor Type: DoubleSignal-24

This is the only setting that works correctly. Don’t change it unless you know what you are doing

Designated Assist Level: By Display’s Command

In order to change the number of assist levels with your display set this to ”By Display’s Command”. This is the only setting that makes sense because it’s convenient to be able to change this in the display settings.

Speed Limit: By Display’s Command

In order to change the speed limit with the help of the display you have to set this to ”By Display’s Command”. If you want the e-bike to be limited to a certain speed that cannot be changed on the display, you have to assign a certain speed to this setting. If you want the e-bike to limited to 25km/h, select 25km/h. You then can’t change the speed limit on the display of the e-bike. This can be useful depending on the laws in your area.

Start Current: 10

This setting will determine how quickly the motor gets up to full power. Which will play a factor in how fast the e-bike will accelerate. I recommend 10 because then your drive train won’t be under a lot of strain as you accelerate. If you want higher acceleration you can set this value to 20 or 30 but, keep in mind your drivetrain will be under less strain during take-off with modest values.

Slow-start Mode(1-8): 4

This setting will decide how fast the current will increase when accelerating. I recommend 4, because this is a nice sweet spot. If you increase the slow start, your start will be really slow and jerky. If you decrease the slow start, you will accelerate faster but, keep in mind your drivetrain will be under less strain during take-off with modest values.

Start Degree (Signal No.): 4

This setting will decide after what number of steps the motor will start assisting. I recommend 4 because this results in a responsive system. It also is not too responsive, which is good. If you want the pedal assist to start the fastest when you just pedal a small bit, change it to 2. Changing it to 0 or 1 may cause problems, so I do not recommend it.

Work Mode (Angular Pedal Speed/wheel*10): Undetermined

Changing this setting doesn’t do anything noticeable. Leave it to default which is undetermined.

Stop Delay : 25

This setting will determine how fast the motor will stop assisting when you stop pedaling. If you have brakes sensors installed, I recommend 25, because it is nice that it won’t stop immediately. And if you want the motor to stop straight away, you just hit the brakes. If you don’t have brake sensors, however, set this to 10. 10 is the lowest value that will work properly.

Current Decay (1-8): 8

The lower this setting, the faster the drive unit will decrease power as you pedal faster. You don’t want the power to cut down a lot if you pedal faster, so leave this to 8.

Stop Decay : 0

This setting determines the amount of time the system takes to reduce the power when you stop pedaling. For safety, I recommend the motor stops assisting immediately, so I leave this setting at 0.

Keep Current: 80.

This is a very important setting that determines how much effort the rider has to put in to maintain a constant speed. Lower values mean the motor does less work which saves battery but the rider has to do more work. Higher values mean the motor does more work which uses up more battery but the rider isn’t having to work so hard. Ultimately it’s a balancing act between battery usage and rider effort that you have to decide between. My preferred number was 80% since my assist levels are set at 10% increments, they already gave me good control over battery consumption.

Start Voltage : 11

This setting will determine the throttle response. Leave this setting to 11, changing it can give problems to the response of your throttle.

End Voltage : 36

This setting decides at which level the throttle will stop. If you want a wider range of control with your throttle you can set this to a maximum of 42.

Mode: Current

This setting decides whether the throttle acts as a current throttle or as a speed throttle. I recommend “current” since this is easier to calculate by your controller. If your throttle responds jerky, you can try setting this to speed.

Designated Assist Level: By Display’s Command

This will decide how many levels of throttle power you will have. I recommend this setting to be the same as the amount of pedal-assist levels. Therefore leave it at ”By Display’s Command”, then it will be the same as what is set on the display’s settings. The setting on the display will set this setting and the pedal-assist setting at the same time. So they always will be equal. Take care not to hit the throttle in too high of a gear in level 9, this can burn out your controller.

Speed Limit: 30km/h

This setting doesn’t imply that the maximum speed with the throttle is 30km/h. The speed limit is overwritten by the throttle, so you will go as fast as you want. This setting works as a sort of cruise control, If you pedal and use the throttle at the same time, the motor will cut off above 30km/h. So you can maintain that speed. So set this setting to the desired ”cruise control” speed.

Start Current : 10

This setting will decide how much current the motor will immediately draw when the throttle is engaged. I do not recommend settings this higher than 10, otherwise, you risk wheelieing the bike because of the power. You also risk burning out your controller if set too high. If you have a weak drive train or IGH decrease this number even more