I'm well on my way with my electronics lab. It's low budget, but functional. I have a nice little assortment of components and can actually go in and build simple circuits with what I have in stock... yay. But, the lab is a LOOOOONG way from complete or well-equipped. I don't have a power supply which makes experimenting really hard. Mostly, I've just used batteries. A Radio Shack 200-in-1 electronics kit was for a long time all I had... I still pull it out once in a while to experiment. Obviously, there are huge limitations to not having an adjustable power supply.
A few days ago, I down loaded Kicad, took a tutorial and began laying out (schematic) an adjustable PSU built around the LM350 and an ATX PSU for the source. I just copied the circuit in the Onsemi datasheet. I built the basic circuit on a breadboard to test, substituting this or that component for what I have in stock. It worked as expected. I then went back to kicad using my actual components and laid the components out in PCB mode, hand routing the traces. I was quite satisfied with the results. I was able to use generic footprints for just about everything.
This past week, I finally received the last of the materials I needed to etch boards, but decided this would be easy enough to do on a protoboard (perf-board) instead. After completing the board, I excitedly plugged it into the computer PSU. Nothing blew. No smoke. Seemed good. I connected the volt meter. 11V. So far so good. I adjusted the variable resistor. Nothing. Voltmeter stayed within a couple tenths of a volt. 20 minutes later I found the problem. From left to right, the printout of my circuit, PCB view, showed (in tiny font) that the pins were number from left to right, 1,3,2. When I wired it, I didn't bother to look at the footprint because I knew how the pins were numbered. But, KiCad apparently did not know. I realize the models can be wrong, but I didn't expect it. Is this a common problem? Luckily, no harm was done this time. I reversed a couple jumpers and now I have an adjustable power supply. But, I'm wondering how often component get fried for similar problems. The LM350 is one of their stock components. Or, is there something I didn't do, that I was supposed to?
A few days ago, I down loaded Kicad, took a tutorial and began laying out (schematic) an adjustable PSU built around the LM350 and an ATX PSU for the source. I just copied the circuit in the Onsemi datasheet. I built the basic circuit on a breadboard to test, substituting this or that component for what I have in stock. It worked as expected. I then went back to kicad using my actual components and laid the components out in PCB mode, hand routing the traces. I was quite satisfied with the results. I was able to use generic footprints for just about everything.
This past week, I finally received the last of the materials I needed to etch boards, but decided this would be easy enough to do on a protoboard (perf-board) instead. After completing the board, I excitedly plugged it into the computer PSU. Nothing blew. No smoke. Seemed good. I connected the volt meter. 11V. So far so good. I adjusted the variable resistor. Nothing. Voltmeter stayed within a couple tenths of a volt. 20 minutes later I found the problem. From left to right, the printout of my circuit, PCB view, showed (in tiny font) that the pins were number from left to right, 1,3,2. When I wired it, I didn't bother to look at the footprint because I knew how the pins were numbered. But, KiCad apparently did not know. I realize the models can be wrong, but I didn't expect it. Is this a common problem? Luckily, no harm was done this time. I reversed a couple jumpers and now I have an adjustable power supply. But, I'm wondering how often component get fried for similar problems. The LM350 is one of their stock components. Or, is there something I didn't do, that I was supposed to?