I think this is maybe like part 3 of the ongoing saga of Hamvention power supplies. When I got my first power supply working it was just running unloaded on the bench. Basically just checking the the voltage stability and making sure nothing blew up. In the past I’ve seen some supplies work fine this way but fail under a load. Sometimes there’s considerable voltage drop, or some type of failure in the the regulation of a set voltage. I have one supply that seems to eat LM 723 chips.
I still have a couple small components to solder in but right now I’m waiting on the mail to deliver them. In the meantime I thought it may be useful to put a static load on the supply. This should allow me to verify it’s regulation and hopefully stress it enough that any problem might come to light. I’d rather find an issue now that after I go to the trouble to set it up as my whole shack power supply. I found some 75 W 12 V lamps at the hardware store. I think they’re intended for low voltage track lighting or some such. I wired up some connectors for the bulbs and hooked the whole mess up to the supply. The first one worked fine so I connected the second. Finally, the third was in line. It ran this way on several occasions so I think this supply will be a winner. The test isn’t a true simulation of what would occur during typical SSB or CW intermittent operation but at least I know the supply can hold up to the current demands for a specified amount of time.
After I set up this whole test stand contraption I was bored. Nothing to do but watch the lights and make sure nothing caught fire. Those bulbs put out some crazy amounts of heat. I didn’t dare leave it unattended. So, I decided to make a little video for youtube. I’ve had it on my channel now for a few weeks. Hope everyone enjoys it! This is basically a trial run for the next supply. It needs a little more work so I hope to get all the bugs out with this one.