I think these will burn up most Transformers, there's a national semiconductor power supply guide from the 70s or 80s online, it says when spec'ing a transformer, if you use a full wave bridge Rectifier with a capacitor, the ac current is approx 1.8 times your dc load current. This is because when the diode starts to forward conduct not only does the transformer need to charge the capacitor back up, it also needs to provide the output current too. I'd say with 3.1A (say 3A output plus a max of 100ma for biasing) you need a transformer secondary rated to 5.6A so atleast 140VA on a 24v winding. If you use a centre tapped transformer then it's 1.2x load current per secondary, as only one winding provides the full current at any one time, 180VA with 12V + 12V Otherwise any longterm use it will cook the transformer. Interested to see where you go next with this project!
@Taylor_26GE93 Why would it burn up a transformer? Toroidal transformers are very efficient and if you use a quality toroidal the regulation is excellent. Maybe you should put a link to the article.
@@Taylor_26GE93 yes please if you can. I would as a rule always use a transformer that is at least 50% more capable than what I need. Example.. RIgol DP832 has 185 watt total output but it has a 400VA toroidal transformer at its heart. Reading the 'original' documentation for this RED kit supply, the transformer is used to limit the output current. Hence in the documentation it states verbatim... "the quality of the supplies output will be directly proportional to the quality of the transformer"
Hi, at 9:50 when you turned the power on the meter showed 12V for on instant before returning to 0, not sure if it is a meter issue or a PS spike what could be dangerous. Thank you very much for expending time and money on testing this little red bastards :-)
@carloca71 I will check that spike out and get back to you. I had to find out if it was a component issue or not, and now I, we know. Well worth the expense and time to get the question answered once and for all.
Well that was interesting sir? It was just the shoddy chinese components. Sign. Im thinking now I might buy some new transformers from Farnell myself. Here its not called Farnell. I think Berkshire Hathaway bought the company yet hasn't changed the name.
