I returned it. That board was strange. The soldering was clean and nice, the components all looked good, there were no scorch or burn marks. Whatever was wrong with it wasn't apparent to me. It looked like a gem compared to the first board I had.If you still have the bad board, you might try repairing it for a spare.
Down to 3Got 4 Crydom D1D40 DC SSR’s for sale.
Thread 'Induction annealer - DIYers'
https://forum.accurateshooter.com/threads/induction-annealer-diyers.4063417/
You are correct. I looked up the specs and it's rated at 21A max. I guess I need a bigger coil.Sounds like the supply was trying to supply more than 20A at 48v so it folded back.
It appears the case in the lower right was heated a bit too far down.
Hi,So I switched my annealer over to pulling the induction board gates low to turn the board off - this time with the Schottky diodes (duh). Seems to work just fine based on the limited testing I've done. Much better than switching 48V high current to the induction board. The image below shows the connections (purple and grey wires) to the solder pads of the induction board's R1 and R2 - the sides closest to the board's HEXFETs. I'm pretty sure anyone can manage this mod to the board.
View attachment 1333117
On the other end of these wires I attached the two Schottky diodes (part 1N5818) to isolate the two. Ground these two wires however you see fit (Arduino, controller, Sestos timer) and the board will turn off. No need for an automotive relay etc.
View attachment 1333118
You have 2 options as a "second grater"Hi,
Thank you for your help in advance.
I've been working on MKNZ arduino based annealer currently. It has been working fine but SSR keep shorting and puts my induction coil in a "runaway train" state. Melted a case or two already. Please excuse my lack of electrical knowledge.
I took advice from another forum and ordered a general purpose 2 gate mechanical relay in order to use the mechanical relay instead of the SSR. The output from the Control board that supplies the SSR is only around 6V. Unfortunately the general purpose relay operates at 12V DC. The General purpose relay is not being tripped. I did check the voltage output from the Control board when I activate the start button and the relay is only getting 6V.
I will reach out to MKNZ but is there a way to use that 6V signal to activate the 12V general purpose relay? Can I use a Boost Converter? Is there any other options?
@D_Pat does not have 12v signal from his control board (only 5 V is available from Arduino) in order to be able to drive directly the proposed SSR. See "Technical Data Sheet" Coil Data.Here's a link to the automotive relay I have used successfully in the past
A simple MOSFET can control the flow of 12V through its coil.
I no longer use this as I simply pull the induction board gates low to turn it off as described above. No more switching high-current 48V. I switch 200mA of 12V.