https://i.stack.imgur.com/YaRcd.png How it's wired. With my wiring, the USB wires are heating up to around 200-300F. Am I using the right...

https://i.stack.imgur.com/YaRcd.png How it's wired. With my wiring, the USB wires are heating up to around 200-300F. Am I using the right voltage? Is the iPad demanding too much power? The PSU worked fine after the incident.

Gentlemen, In the PSU section of that old Tek oscilloscope I've been troubleshooting, I discovered several transistors had died. One of these...

Gentlemen, In the PSU section of that old Tek oscilloscope I've been troubleshooting, I discovered several transistors had died. One of these is puzzling me somewhat. It's a 2N5859 which they're using to drive one of those big ol' TO-3 power transistors for the -15V output section. I can't understand why they chose a fast switching device with a GBP of 250Mhz. This being a linear PSU, ...

Here is my 2W +/-45V PSU http://kvisit.com/S_KuKAw See the MSD7342-224ml for coupled inductor. The IRF9640 is overkill but only SC3...

Here is my 2W +/-45V PSU http://kvisit.com/S_KuKAw See the MSD7342-224ml for coupled inductor. The IRF9640 is overkill but only SC3 model available. The control loop should be pretty straight forward. What is the input voltage range desired? I would copy in that neat net + wiring list that you guys use but do not know how. Just learning LTSPICE. Cheers, Harry

I need another PSU on my bench and I remembered I had this thing in my junk closet, a SMPS-based supply from www.mpje.com. Something was...

I need another PSU on my bench and I remembered I had this thing in my junk closet, a SMPS-based supply from www.mpje.com. Something was wrong with it I couldn't remember but all I recalled was this is what the power PCB looked like, from the "factory" mind you:

https://i.stack.imgur.com/dJmy2.png It has 3 long pads and 11 shorter pads, which to connect to power on? I can't find a pinout.

https://i.stack.imgur.com/dJmy2.png It has 3 long pads and 11 shorter pads, which to connect to power on? I can't find a pinout.

I want a switch mode PSU which will give me two ~2A outputs at 5V above and below a nominal +50V (say +40V to +60V) DC supply, ie +55V and +45V...

I want a switch mode PSU which will give me two ~2A outputs at 5V above and below a nominal +50V (say +40V to +60V) DC supply, ie +55V and +45V from +50V. I can probably work out some fairly clunky ways of doing this, but it seems possible that there's some topology particularly suited to this type of thing. Any thoughts? Cheers -- Clive

Greetings, gentlemen, I'm attaching a scan of the rectifier board from an HP8547A network analyser. I'm just wondering how the designer(s)...

Greetings, gentlemen, I'm attaching a scan of the rectifier board from an HP8547A network analyser. I'm just wondering how the designer(s) arrived at the choice of value for the caps across the incoming supply from the mains transformer secondary windings (the caps immediately before the bridge rectifiers)? In case you can't make it out, the values are 0.047uF, 0.22uF, 0.47uF and 0.04...

Gentlemen, I know this will upset and disappoint a certain antipodean contributor here, but I would like, if I may, to discuss electronic...

Gentlemen, I know this will upset and disappoint a certain antipodean contributor here, but I would like, if I may, to discuss electronic design for a moment. This concerns a linear power supply regulator board from a Tek 7000 series scope. Some of you may recall my infatuation with vintage test gear and this is the latest subject for attention. This board produces the following voltage...

I have just found this pretty bizarre idea: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.665.5375&rep=rep1&type=pdf It uses a...

I have just found this pretty bizarre idea: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.665.5375&rep=rep1&type=pdf It uses a transformer to limit the voltage swing at the resonant capacitor. Great, but why wouldn't they use a bidirectional TVS for the same purpose? That wouldn't result in a paper, eh, would it? Best regards, Piotr

I was looking to order some low current MOSFETs and realized all the popular items had thresholds of 3 volts and higher. I would like to use...

I was looking to order some low current MOSFETs and realized all the popular items had thresholds of 3 volts and higher. I would like to use something that turns on pretty well at 3 volts so it won't need a 5 volt PSU. Any suggestions? I'm looking for a TO-92 case preferably but surface mount will be ok too. I could have sworn some years ago I tracked down a number of low threshold...

My PSU has an "economy mode" that turns off the fan most of the time the computer is barely being used (you know, like posting to USENET)....

My PSU has an "economy mode" that turns off the fan most of the time the computer is barely being used (you know, like posting to USENET). However, naturally the design assumes it will be right side up. Does having it on its side and allowing the fan to stop present any overheating hazard to components? Of course normally heat rises. I just cleaned it out. You know how dirty stuff get...

Hi to all my pals, on the bench I have a US made, bass instrument amplifier (Eden) in near new condition. It uses a 600VA toroidal tranny...

Hi to all my pals, on the bench I have a US made, bass instrument amplifier (Eden) in near new condition. It uses a 600VA toroidal tranny in the PSU. The "T5A" 20mm AC fuse installed was blown and also a similar previous fuse, I'm told. Nothing wrong found with the amp when a new fuse was fitted. However, repeated switch on testing shows max, peak inrush surges over 120 amps, either ...