So lets keep this generic..if I need +/- dc voltage for one circuit pulling a heavier load, and a positive only dc regulated voltage of another part of the device pulling a light load, and have only one transformer with dual secondaries, can I take the light load from only the one rail without upsetting things too much? I have a (poor) diagram below to help me explain. I know there are no fuses, etc.. this diagram is only to quickly illustrate my question and is not a final design.
Thanks!
Thanks!
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Sorry, you're right. My bad. Misread the 24V 1A as the 'main voltage requirement'.
One could add a separate, second bridge rectifier across the secondary series transformer output but looks like the OP would then have to 'tame' a high voltage to meet requirements (assuming the second supply is required for driving relays or similar).
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three terminal (3T) regulators need 3V headroom (min) . more than that heat sinking and power waste become a concern. check v span unloaded to max load from the transformer.
BTW > Better grounding is thru 2 bridge rectifiers grounded after the Capacitor banks. instead of grounded at the transformer using a single bridge ( good threads on this )
BTW > Better grounding is thru 2 bridge rectifiers grounded after the Capacitor banks. instead of grounded at the transformer using a single bridge ( good threads on this )
a heavy pulling amp can cause voltage drop
and even if only small, the little headroom you have have for the low power voltage reg might be gone
can be done, usually only for low voltage and low power , other than that it becomes impractical, fitting more copper on a limited area.
wind 10 or so turns using a gauge properly sized for the current. lightly loaded, measure the voltage > calculate volts / turn . to decide.
I'd use both rails if I knew how and if it would work, then they could share the load. How would I do that. I don't mind using a couple regulators if need be.
not enough info to answer
what exactly are the two loads?
what transformer? the data sheet has some info on regulation and loading. use it to calc. the equivalent R of each winding.
if the aux reg current is a significant % over the other side a misbalance can exist.
quiescent conditions are probably worst case.
It just takes ohms law here.
It shouldn't be a problem as long as the load on the positive voltage is light , like to power a couple opamps in single supply mode ....
Ive built a few chip amps that had a preamp tone control section using a couple opamps in a single supply configuration and didn't have any problems but I was probably using less then 30ma of current ....
Ive built a few chip amps that had a preamp tone control section using a couple opamps in a single supply configuration and didn't have any problems but I was probably using less then 30ma of current ....
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