How about something with galvanic isolation like the Allegro ACS733 which has a resistor-programmable Op-Amp comparator that triggers at a peak value by-design. Base-band covers D.C. 0 Hz to the Mhz range. Though i've got to wonder about its Hall-effect interface inside: that might require shielding, or perhaps the potential fantom component can be exploited in a productive manner.

@BrianDhvTinkerer

4 ай бұрын

Good idea. Got to look into that.

Hi Brian, I recently ordered the Chinese black capacitors you mentioned. I hope I can get better results. While they arrive, I would like to investigate and make the protection circuit that you show in the video, I find it very interesting to add it to my induction system. You can share the diagram or the links where to investigate. thank you.

@BrianDhvTinkerer

4 ай бұрын

Here is the diagram- hope it helps! teslascience.wordpress.com/simple-and-effective-induction-heater-current-control-circuit/

@BrianDhvTinkerer

4 ай бұрын

I’m collaborating with another guy to improve this even further and will post the updates

@haronwepworking5806

3 ай бұрын

@@BrianDhvTinkerer Hello brian the current control circuit i s a great idea better then a circuit breaker but when i try to open this link it says "page not found" could you please update the link thank you!

@BrianDhvTinkerer

3 ай бұрын

@@haronwepworking5806 sure

@BrianDhvTinkerer

3 ай бұрын

@@haronwepworking5806 I worked on a new version of the circuit which is completely solid state and works in my test. Here is an example of the test run.

Сколько там киловат?

@BrianDhvTinkerer

4 ай бұрын

I tested at 1.8 kW but this can be increased much more!

Hi Brian, if you could reply to my comment on your "Make Small powerful Induction Heater" video, I wouild greatly appreciate it. Basically I'm pumping almost 2 kW into my induction heater but I still can't melt stuff. Thanks

@BrianDhvTinkerer

4 ай бұрын

Hi just saw your comment. Are you using the Autotuning setup that I’m using?

@gaynzz6841

4 ай бұрын

@@BrianDhvTinkerer I'm still using manual tuning (with 555). Watching on the oscilloscope, I tune the frequency so that the voltage across the tank circuit reaches its maximum, which is also when the bridge draws maximum current. Do you think that's the issue? The strange thing is that you had a lot better results in your own manual tuning designs. Well, I do want to try your Autotuning setup, I believe I have all the parts needed. Just to recap, if I understood correctly, you divert a small fraction of the copper tube current off to the side, into a thin wire which passes through a ferrite toroid (current transformer). This signal is then amplified by the amount of turns, and terminated with a bleeder resistor. After that, using diodes and z-diodes you make the signal "safe" for input to a 5v logic chip, and feed it to the Schmitt trigger. Oh, and for startup, you use a 555 signal and tune it "just about right" so that the autotuning mechanism can take over. I read your instruction many times, hopefully that's all correct!

@BrianDhvTinkerer

4 ай бұрын

@@gaynzz6841 yes if tuned precisely, the manual set up works very well. However, the auto tuning set up always stays in tune. In this video, I’m using a current sense which senses the amount of current in the tank circuit. If the current is too high, then the circuit detuned to a higher frequency which cuts the power. The overcurrent trip occurs when the workpiece is removed from the coil which causes a current and voltage rise in the tank circuit. I think the problem that you are having with your set up is the capacitors are very what’s called lossy. Heat dissipation in the capacitors causes the inefficiency. I would recommend these www.easternvoltageresearch.com/capacitor---0.47uf-2kv-940c/ Or these www.ebay.com/itm/305383261719?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=xfheltcdqze&sssrc=4429486&ssuid=Z9ZBUuQvS8u&var=&widget_ver=artemis&media=COPY

@gaynzz6841

4 ай бұрын

@@BrianDhvTinkerer Thank you. My caps do reach 60 deg C, but I wasn't sure if that's normal or not, because pretty much everyone says their capacitors are getting hot. It's possible they might be too lossy.

@gaynzz6841

4 ай бұрын

@@BrianDhvTinkerer I've seen those capacitor in lots of builds, especially the white round ones... Any idea why they are so much better for induction heating (and even DRSSTCs etc) than "ordinary" impulse capacitors? I mean, pretty much any polypropylene pulse cap is trying to have very low ESR, ESL, and so on and should be fine for such applications, so what's the big magic here?