Salas,
I need 12v for a relay based remote control and wanted to get you opinion on using the secondaries used for heater reg to run a reg for the controller as well. Is the a bad idea? Should I get a seperate small transformer.
I need 12v for a relay based remote control and wanted to get you opinion on using the secondaries used for heater reg to run a reg for the controller as well. Is the a bad idea? Should I get a seperate small transformer.
Scope the controller's rail to see if any controller generated noise rides it. Use batteries for that test. If its clean use the same secondaries.
Salas et al.
I would like to use two isolation transformers to get enough volts for the preamp,
It is OK to combine secondaries in series AFTER RECTIFICATION isn't it? I know the secondary voltages won't be 120 and 240, but it's safe to do this, right?
See diagram
I would like to use two isolation transformers to get enough volts for the preamp,
It is OK to combine secondaries in series AFTER RECTIFICATION isn't it? I know the secondary voltages won't be 120 and 240, but it's safe to do this, right?
See diagram
Attachments
Its usually combined by connecting after the rectifiers the bottom of an upper circuit filter / reservoir cap to the top of a lower circuit's one. Just like when stacking batteries.
Yes, but it takes two transformers or two independent secondaries like in your previous schematic. The output is + & 0 while each bridge is connected across each secondary.
Yes. I have two separate transformers. Maybe add two 330K resistors to the capacitor stack, as you do when you stack caps for high voltages?
Thanks SO much.
Thanks SO much.
to Doug in Indy
the (-) from upper bridge connect to the (+)from the bottom bridge, not to the ground as your schematic.
the (-) from upper bridge connect to the (+)from the bottom bridge, not to the ground as your schematic.
Although looking electrically the same if doing it correctly at the bridges, its physically preferable to avoid excess wire runs between the reservoir capacitors and to combine them locally.
Doug do you need +- PSU or only + PSU?
If you need only B+ isn't necessary the 2nd bridge rectifier.
If you need only B+ isn't necessary the 2nd bridge rectifier.
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I thought that was unsafe, because it subjects the secondary windings to higher voltage than they were designed for.
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