Induction Heater PSU suggestions and 'how it works" - Page 1
Forum section: electronics / projects

author: EvilSOB
author_rank: Newbie
timestamp: December 24, 2020, 01:58:54 am
content: Hi guys.Ive just gotten the following induction heater off ebay...https://www.ebay.com.au/itm/1000W-ZVS-Low-Voltage-Induction-Heating-Board-Module-Heater-Coil-12V-48V-Driver/312886217509?hash=item48d978cb25:g:jKYAAOSwp5ld8Mef&frcectupt=trueWhich I intend to use with small jewelry projects at this stage, with metal types and sizesdependant on what this heater can achieve.I dont have a PSU yet so I am after some understanding of how the psu affects performance.Basically the unit operates from 12-48V DC with a max of 20A, and my question is how well doesthe unit heat stuff at low voltage/high amp versus high voltage/low amp.As in, if I run it DIRECTLY off a car battery (12v high amp with no voltage or current control), does this ::1) limit the size of the target object that can be heated2) increase the time required to heat the target object3) limit the maximum temperature of the target objector some combination of the above.OR ... If I run it off a 36v 5A variable power supply, how will theachievable results vary from the above example.Secondly, any suggestions on PSUs or PSU designs that would enable to to drag the bestperformance/results from this heater. Also I assume the PSU needs to be variable voltage / currentand current limited.Also any advice / suggestions from experienced Induction heater users would be appreciated.Thanks guys.EvilSOB

author: Doctorandus_P
author_rank: Super Contributor
timestamp: December 24, 2020, 03:44:24 am
content: Quote from: EvilSOB on December 24, 2020, 01:58:54 amIt does not work that way.Those ZVS circuits are just very simple oscillators. If you increase the input voltage, then also the current increases, and if you go over the maximum the FET's can handle, the magic smoke escapes. Those cheap circuits have no protection whatsoever, just enough to make it oscillate.Running them at too low a voltage is also likely to destroy the FET's because the gate drive is not strong enough. If you can find one with real gate drivers, that would be a plus.I've collected a bit of information on those things but never got to buying one because the power supply was a lot more expensive then the ZVS circuit, and the total was a bit too much.

author: NiHaoMike
author_rank: Super Contributor
timestamp: December 24, 2020, 03:58:10 am
content: Quote from: Doctorandus_P on December 24, 2020, 03:44:24 amFor 48V, telecom "rectifiers" are pretty cheap. Presumably they can be hacked to lower the output voltage to get some control over output power.

author: EvilSOB
author_rank: Newbie
timestamp: December 28, 2020, 02:13:20 am
content: NiHaoMike ::Thanks, that sounds like an idea. BUT ... can you please post a link to one of these"Telecom Rectifiers" you speak of. Im finding many results to that search-termbut Im not finding anything near small enough. All I'm finding is 100A+ stuff...Thanks.Doctorandus_P ::Cool, they work on the wattage rather than V or A, as I suspected.Thanks dude.So at this point, because I'm getting old and lazy, Im not going to BUILD a dedicated PSUfor this thing ... Instead I'm going to cobble it together as modules.That way, the money I spend on this PSU isnt ONLY for this heater, but can be used withany other 'oddball' projects I come up with ...Assuming, of course, that NiHaoMike doen't find me a 'telecom rectifier' that looks more interesting.So, Im looking at getting a Power supply LIKE this (1000W version)https://www.ebay.com/itm/48V-150W-240W-360W-400W-500W-600W-720W-800W-1000W-Switching-Power-Supply-for-Led/202874255811?hash=item2f3c3f79c3:g:O40AAOSwUvheF9o4And a controller LIKE this (1000W version)https://www.ebay.com/itm/WZ5020L-50V-20A-1000W-CNC-Adjustable-Step-Down-Module-Buck-Power-Supply-w-LCD/114318200824?hash=item1a9de54ff8:g:BA4AAOSwpbhfpRvzAnd I will build them together into their own pretty box.Ideas / suggestions anyone?Thanks again.