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ZVS Power Resonator – CRO-SM1

Rated 5.00 out of 5 based on 1 customer rating
(1 customer review)




The new CRO-SM1 is an ultra compact induction heater circuit and ZVS transformer driver designed for embedded applications.

The CRO-SM1 is a type of collector resonance oscillator circuit which will automatically drive reactive circuits at their resonant frequency. This is ideal for making a DIY Induction Heater or Solid State Tesla Coil. 

Available as circuit only, or fitted with either a 50x50x13mm heatsink, or a 50x80x27mm heatink for higher power use. If mounting on your own heatsink, you must use a thermal interface material to prevent short circuit.

To use this circuit, you will also need a suitable choke and possibly a Polypropelene Capacitor.

This is designed to work with a wide range of coil sizes and operating frequencies to give maximum performance. The device to be resonated needs to consist of a coil and parallel capacitor bank. The circuit will automatically drive at resonance even if the resonant frequency changes such as when a metal object is placed inside an induction heater.

We highly recommend using a  12V current limited PSU24V current limited PSU, or bench top PSU to power this circuit. Large batteries should not be used unless you have tested your setup and determined the battery can supply the right power. It can also be very useful to monitor the voltage and current flow from the PSU as it helps you to know if the circuit is oscillating or if the PSU is reaching its limits. For this we have a Voltage and current meter. You can also use our Digital Multimeter which can measure the frequency directly (up to 100kHz)

When used with our Induction Coil Assembly, or Induction Coil KIT (for making your own custom coil) the circuit should draw around 4A from a 12V supply if there is no metal object within the coil. When adding something to be heated, the current will increase significantly and will vary with the size of the object and the material it is made from. If using the KIT version of the coil assembly, the amount of standby current will depend entirely on how you build it.

Our transformer kit is a great partner for the CRO-SM1 as it allows for more flexibility on coil design.

The power output can be modulated (for temperature control) using a PWM circuit such as our PWM-OCm or PWM-OCX

  • Automatically resonates low impedance reactive circuits
  • Wide supply voltage range (12V – 30V)
  • ZVS (Zero Voltage Switching)
  • Current up to 10A continuous*, 70A peak
  • Modulation input
  • High quality double layer PTH, 2oz Copper PCB
  • Dimensions: L50 x W50 x H8 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…

 Click here to download the CRO-SM1 Instruction Manual 

How hot can I get my metal part with the CRO-SM1?

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 850C using only a 12V supply with less than 100W of power input.

Can you make me a more powerful version?
We are working on a larger version which operates differently and allows for more power. Check our newsletter or Facebook for updates. We also have a range of heatsinks and cooling accessories
 available that can allow for more power.

Related Articles:
DIY Induction Heater

Related Videos (links open in new window)
CRO-1 Overview (the CRO-1 is discontinued and has been replaced by this CRO-SM1)

Additional information

Weight 0.15 kg
Dimensions 50.00000000 × 50.00000000 × 8.0000000 mm

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Review (1)


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  1. Rated 5 out of 5

    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.