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Induction Heater Circuit – CRO-SM3

(1 customer review)

Our induction heater circuit, the CRO-SM3 is an ultra compact resonant drive circuit designed for low power induction heating in embedded applications. At only 50 x 50mm (under 2 inches), this feature packed digital induction heater circuit can be integrated into all sorts of devices.

Also can be used as a ZVS transformer driver and wireless power applications.



The new CRO-SM3 is an advanced, ultra compact digital induction heater circuit and ZVS transformer driver designed for embedded applications.

  • Ultra Compact & Efficient
  • Adjustable power levels
  • Digital protection circuits
  • Simple on/off push button operation
  • Auto heat regulation or workpiece detection using external connections or sensors
  • Low voltage DC operation
  • Modular connectivity for advanced features & product integration
  • ST and PRO versions available (This listing is for the ST version. PRO version coming soon)

New CRO-SM3: Digital control Induction Heater & Power Resonator

Customisation is available for this product: We can help you develop your induction heating projects

Feature comparison of induction heaters



Please note that printed manuals are not supplied. Click Here for the CRO-SM3 Datasheet / Instruction Manual

Our new CRO-SM3 induction heater circuit will automatically drive reactive circuits (coil and parallel capacitor) at their resonant frequency. This is ideal for making a DIY Induction Heater or Solid State Tesla Coil. The new digital control system allows for advanced protection and interfacing with displays.

The power stage of the CRO-SM3 will keep the system in resonance even when something changes like adding metal to an induction heater coil or reaching the curie point. The digital circuits monitor the frequency and power levels to make sure it will keep working smoothly, and also for sending information to a display such as the resonant frequency, current, error codes and more.

The CRO-SM3 induction heater system is a modular device allowing you to build your own custom induction heater quickly and easily. The CRO-SM3 is the main driver board which can then be stacked with tank capacitors, chokes, coils, and a user interface. The simple connections allow for very compact systems and flexibility in layout and integration. The optional display can be very useful for experimentation as it allows the operating parameters to be monitored during use. We also offer a customisation service where we can write custom firmware for alternate displays or for interfacing with other devices.

Expansion connector cables are now available.

Available as circuit only, or fitted with either a 50x50x13 mm heatsink, or a 50x80x27 mm heatsink for higher power use. If mounting on your own heatsink, you must use a thermal interface material to prevent short circuit.

We have a selection of highly compact induction heater capacitors available.

To use this circuit for induction heating, you will also need a suitable choke, induction heater coil, capacitor, and PSU.

The CRO-SM3 is a compact induction heater module designed to work with a wide range of coil sizes and operating frequencies to give maximum performance in a highly compact package. Available in ST or PRO versions with the PRO version having additional features such as RS-232 control, automatic temperature regulation, power regulation, and more.

The power output can be selected (for temperature control) at four levels 25%, 50%, 75%, and 100%. At powers below 100%, the output is modulated by turning off and on every second.

  • Automatically resonates low impedance reactive circuits
  • Wide supply voltage range (12V – 26V)
  • Digital Control
  • Self protection from under voltage, over voltage, over current, overheating, and resonance failure, 
  • ZVS (Zero Voltage Switching)
  • Current up to 20A continuous*, 70A peak
  • Optional OLED Display
  • High quality quadruple layer, copper filled PTH, 2oz Copper PCB
  • Dimensions: L50 x W50 x H6.8 mm (without heatsink)

Example Applications

  • Induction Heating: Materials Research, Nanoparticles
  • Flameless non-contact heating
  • Ammo case annealing
  • DRSSTC (Solid State Tesla Coils)
  • DC-AC Power Inverters
  • Resonant Energy Experiments
  • Wireless Power Transmission
  • And more…

How hot can I get my metal part with the CRO-SM3?
The temperature rise in the material depends on many factors such as what the material is, the size, shape, how quickly it looses heat to the surroundings, operating frequency, and the dimensions of the heating coil. We can not answer questions relating to specific heating projects as there are too many variables to consider. If you consider that using a 24V input and your system pulls 10A, Then there is potentially 240W of heating power in the system (ignoring losses). You can get a rough idea using our Heater Power Calculator. In one test for a customer, the circuit successfully heated a block of graphite to 850°C using only a 12V supply with less than 100W of power input.

Can you make me a more powerful version?
Please see our new CRO-2, high power induction heater circuit, or the IHM-5K 5kW Induction Heater.

Related Articles:
DIY Induction Heater
Guide to Induction Heating

Related Videos (links open in new window)
CRO-1 Overview (the CRO-1 is discontinued and has been replaced by this CRO-SM3)

Review (1)


Only logged in customers who have purchased this product may leave a review.

  1. Cleber Costa

    Hello How do you do? Do you send to Brazil?

    Reply from RMCybernetics:
    Yes we ship worldwide. Please do not use this form to ask questions. Use the contact us page instead.