Electronic – Two switching wall warts for a regulated bipolar supply

power supply

Can I connect in series two identical switching wall wart supplies (12 V each) that have no measurable resistance between either DC output pin and either ac pin (measure open and have no ground plug) to make a regulated power supply (±9 V) like this? If so, any hints on how to improve the circuit? I want to power a headphone amp with 300 mA and need a quiet supply.


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Best Answer

Yes you can. No problems at all. In order to use them for low noise schematics, provide good filtering of the linear regulators. Use low inductance ceramics capacitors in parallel with the electrolytic capacitors in the input and output filters. Keep the linear and switching regulators on some distance.