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I have built a half bridge SMPS that outputs 110V at around 5A amps to power a CNC motor. It's based on SG3525 with a GDT. The power supply works fine under resistive loads (some light bulbs), there's no abnormal heating up of the components even after a long time under load, but when connecting...

I'd like to open this topic on transformer cores and calculating them. I've had some issues with my SMPS projects that I guess are related to the transformer core, mainly too much primary current, big inductive spikes on the primary winding, audible noises coming from the transformer or not...

I've been contemplating at building a two switch forward converter for some time. Since I need a power supply for some powered speakers, I thought it's a good time to build one. As far as I've learned about this topology, the advantages are: - single ended drive (it can use any flyback...

I'm building an IR2153 SMPS and I have a problem with the controller. HO doesn't switch, it stays high and blows the transistors. LO switches fine. I measured it both ways just to be sure: - with HO referenced to GND I get HO high and no switching - with HO referenced to VS (with an isolated...

I've built a SEPIC converter and I'm having trouble making it work with coupled inductors. It works well with separate inductors, but with the coupled inductor I get a lot of ringing and the voltage drops and can't go up with a load attached. Schematic: Waveform at the inductor Waveform at...

I've been trying to repair and reverse engineer a welding inverter and came across some interesting circuitry. It uses the UC3845 control chip and a low-high side driver L6386. Since the UC has a single ended output connected to both inputs of the driver chip, it makes me think that it's a...

I've started building a lab PSU using the TL494. The schematic is attached below, it's missing a lot of things but I'm still testing stuff on the breadboard. The problem I have is with the gate drive transformer. When I connect it, it pulls a lot of current through Q1, which quickly heats up...

Greetings, I'm building a variable lab power supply and I'm trying to understand how constant current / current feedback works with PWM. I've been looking at danyk's lab SMPS project that uses UC3845 and a current transformer. According to the block diagram of the chip, the ISENSE pin is...