I just finished rebuilding my PSU incorporating changes you all suggested. This one uses @xrk971's SFPP soft start and SLB rectifier and filter. It's all a rather snug fit inside a Modushop Galaxy 3U chassis. The SLB heatsinks are mounted on a bridge above the SFPP and SLB boards, making it easy to remove them to get underneath to the boards. (In 2 of these photos, the heatsinks are removed.) And I tried to make it easy to swap out transformers by having all of the transformer connections (except chassis ground) go to terminal strips mounted on a bridge near the top.
Up until yesterday, I had 24V transformers (Antek AS-3224) in there, and that was giving me +/-28V powering my F6-Diamond amps. Just yesterday, I swapped those for 18V transformers (Antek AS-3218) that I plan to use with Alpha Nirvana 4R amps. I'm just now finishing those AN 4Rs. Hope to be up and running tomorrow.
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Got a couple of questions regarding a planned outboard PS for various Pass amps. Before I start putting holes in the chassis, can I get somebody to look over my shoulder?
(1) I have a toroidal Avel-Lindberg 500 VA power transformer with (2) 115 volt primaries and (2) 40 volt secondaries. I was planning on putting the 115 V primaries in series, to hopefully get (2) 20 volt secondaries. (maybe a little more than 20 volts. My line voltage is consistently 122-123 volts) OK to do this? Not gonna let the magic smoke out?
(2) I found a couple of LM340k 5 amp 24 volt TO-3 case regulators in my stash. Not the last word in regulation but probably better than a simple CRC? I am currently using an ACA Mini, and have 4 ACA boards mostly stuffed and waiting for their turn in the TTD list. What do you think about using these regulators for my current amp and any other Pass amp projects in the future ?
Thanks for listening. 😉
(1) I have a toroidal Avel-Lindberg 500 VA power transformer with (2) 115 volt primaries and (2) 40 volt secondaries. I was planning on putting the 115 V primaries in series, to hopefully get (2) 20 volt secondaries. (maybe a little more than 20 volts. My line voltage is consistently 122-123 volts) OK to do this? Not gonna let the magic smoke out?
(2) I found a couple of LM340k 5 amp 24 volt TO-3 case regulators in my stash. Not the last word in regulation but probably better than a simple CRC? I am currently using an ACA Mini, and have 4 ACA boards mostly stuffed and waiting for their turn in the TTD list. What do you think about using these regulators for my current amp and any other Pass amp projects in the future ?
Thanks for listening. 😉
As far as I know, you won't be able to halve the voltage.
secondaries in series: 80V 6.25A
secondaries in parallel: 40V 12.5A
https://www.electronics-tutorials.w...ted in series, the same,at 24 Volts, 2.5 Amps.
secondaries in series: 80V 6.25A
secondaries in parallel: 40V 12.5A
https://www.electronics-tutorials.w...ted in series, the same,at 24 Volts, 2.5 Amps.
Sure you can do that. I believe the current rating stays the same for the secondary's in either case though, but yes voltage is halved. NP has mentioned this configuration in the past for being able to use a transformer with "too much" voltage.
The cord connecting PSU and amp is a resistor. So with capacitors before the amps, you get a crcrc (instead of a crcr.)