Help with pulling enough amps for zvs - Page 1
Forum section: electronics / beginners

author: algorithm
author_rank: Regular Contributor
timestamp: December 07, 2022, 08:34:31 am
content: So I have a zvs module for an induction heaterI was told 5a 12v would be fine to drive it. But it seems the coils were saturated at less than potential. Well judging by temperature.I could at best get 300 degrees F. But should be able to reach 400 F.I experimented a lot with the heating element coils magnet wire. Have 3 lengths same ga. 3 turns, 5 turns and 12 turns. They all failed, 5 turns tight being about as close as I got. (Reached 350F but had to have it powered for 20-30 seconds (45 seconds and it pops I think)) all 3 pieces had same resistance at 1.2 ohm.My goal is to be able to reach 400F in 5-10 seconds. I dont want to have to power it much longer than 5 seconds.After a year I got a bigger power brick at 8A. Still pretty much the same. Not like I hoped.Should I try this?https://www.instructables.com/Circuits-for-using-High-Power-LED-s/Seems simple and claims 20A is possible. I could salvage a proper fet and npn.But if my math is right? At 15A for r3 thats .03 ohm? 8 watts?So I would need a 10w cement resistor I guess? I doubt I could find one in my junk at .03.Also thought about using a mains cable, full bridge rectifier and cap/resistor. That would supply enough I figure.Other options I thought of.Use 18650s. Thats too easy of a solution. But im pretty sure thatd work. LolAlso considered depopulating a 2nd zvs module and conglomerating 2 modules into 1. Cause bigger is better. So instead of 2 1200vdc caps, 4. But while that sounds terrifyingly fun I am hoping for the most straight forward solution to get enougb power with a cable.Also I dont want to melt metal with it.Any advice is appreciated. And please forgive my ignorance.This is the only diagram I could find for "mini-zvs" (yellow board on right)

author: Terry Bites
author_rank: Super Contributor
timestamp: December 09, 2022, 03:39:42 pm
content: I cant see the connection to this project in the link about LED lighting.What chokes, MOSFETs and diodes are you using? The choice will be critical to power output and circuit reliability.I think this is the ZVS schematic etchttp://www.kiblerelectronics.com/bob/app_notes/note11/note11.html#section%202eYou must protect the battery pack from overload or risk fire and explosion!

author: algorithm
author_rank: Regular Contributor
timestamp: December 14, 2022, 10:08:31 pm
content: Well the link was me attempting to find the simplest solution to deliver more current or amps to the mini zvs.Haha, good advice about lipo also. While im aware of protection ic requirement I didnt clarify so a valid concern.ALTHOUGH, after watching great scotts video about Induction heaters, I have no curiosity.See my heater appeared to be unable to reach combustion temp at 450 FBut my thermocouple must not be very magnetically ferrous. Also small diameter.But upon inserting a 6mm threaded rod of stainless it melted the heatshrink on the thermocouple and the insulation under the heatshrinkBut yeah im pleased with the result. This was an issue stemming from lack of understanding in the function of the circuit. Rather than a shortcoming in power.