Recent content by jackrod

Some interesting reading here... Discusses inverter/IH topologies. I guess the cheap ZVS would be considered a "current fed half bridge" (Type A, with 2 inductors). This drives a parallel resonant tank, which is what we want, since the current is low when it is empty...

Yeah, not sure if it's the best trick to use, but it seems reasonable. I think you sort of have to do something, otherwise you may be waiting for numerical errors to kick off the oscillation in the sim? But I'm not entirely sure how the implicit solver in LTspice affects that marginally stable...

The 470 and 480 is to help out the simulation a bit. In reality there is always some small tolerance which will make one FET get ahead of the other, but if the simulation is perfectly balanced it can get stuck in a marginally stable state. The transistors could definitely use an upgrade, they...

Cool! I read up some more on the theory of IH, and I think that you are right to start on a higher frequency. This page explains a lot, including that if you try to drive the tank below its natural frequency, the inverter (2 mosfets in the cheap ZVS) experiences a capacitive load and so...

I've been getting interested in induction heater design too :science:. After looking into it, the common circuit used on the cheap blue "12V ZVS" etc modules is kind of crazy, right? It makes sense that the MOSFETs get killed commonly, given that there is no gate driver. And if the work coil and...