Hey everyone, I need some help with a power supply issue. I've got a 48V power supply rated at a max of 20 amps that I'm using for a ZVS induction heater (one of those 1800 watt models). When I tested it with a small IGBT welder, it worked fine because it had a selectable current limit. However, now I want to run it at a higher voltage and lower current, but my power supply shuts off whenever the heater tries to draw more than 20 amps. What I'm looking for is a way to keep the power supply running while limiting the current without completely cutting it off. I think it's kind of like a constant voltage with a variable current setup. Would a special power supply work for this, or is there something I can modify in my existing setup? Any ideas would be greatly appreciated!
3 Answers
Honestly, there isn't a simple device that you can just add to get the functionality you want. You might need to invest in a different power supply that’s specifically designed for this kind of operation. There are DC supplies that maintain constant voltage until the current limit is hit, but those are pretty rare for AC supplies, which is what you'll need for an induction heater. Consider looking for a supply explicitly made for induction heating; it should handle it much better than your current setup.
Check out switching power supplies that offer Constant Voltage (CV) and Constant Current (CC) modes. They maintain a steady voltage up to a specified current limit before changing. You might also find battery chargers with these features, but it could be tough to find one that operates at 48V. Alternatively, see if you can modify your existing supply to work in constant current mode instead of just shutting off.
Have you thought about using a power resistor in line with your heater? By choosing the right resistor, you can keep the current below 20 amps while still drawing power. There are also specialized power supplies with adjustable current limiting that will reduce voltage instead of cutting off completely. That could do exactly what you're after!