Building a Low-Cost Low-Noise Negative- or Positive-Rail Power Supply

RE: Building a Low-Cost Low-Noise Negative- or Positive-Rail Power Supply

cristiano.sar — Sat, 27 Dec 2025 00:12:49 GMT

Very nice, would it be easy to adapt the circuit to accept 12v DC as input?

RE: Building a Low-Cost Low-Noise Negative- or Positive-Rail Power Supply

Jan Cumps — Wed, 13 Mar 2024 16:38:37 GMT

Circuit nitpick: should C1 be outside of the Optional LCD Circuit area?

RE: Building a Low-Cost Low-Noise Negative- or Positive-Rail Power Supply

Jan Cumps — Tue, 12 Mar 2024 18:33:21 GMT

I just wound that transformer. It took me 30 minutes to complete the exercise.

The chop-stick helps to keep everything under control while winding.

RE: Building a Low-Cost Low-Noise Negative- or Positive-Rail Power Supply

ggabe — Tue, 12 Sep 2023 22:15:29 GMT

Nice test. I wonder what a low emission optimized driver, like the SN6507 or LT1533 would do noise and maximum output current wise, with the same transformer.

RE: Building a Low-Cost Low-Noise Negative- or Positive-Rail Power Supply

shabaz — Sun, 10 Sep 2023 13:16:46 GMT

Just in case anyone is curious how to incrementally prototype with toroidal transformer windings.. the photo here shows how an extra winding was added.. simply thread another wire into the existing transformer without desoldering it all off the board. You can see an extra couple of windings crudely soldered in at the 1 and 2 o'clock positions in the photo.

It's all ugly, and eventually I needed a PCB, but for the initial design this worked fine.

RE: Building a Low-Cost Low-Noise Negative- or Positive-Rail Power Supply

michaelkellett — Sun, 10 Sep 2023 09:21:29 GMT

Interesting blog - thanks.

I wonder if there are any off the shelf transformers one might use.

Very hard to search through Farnell's range (or other web sites) because the search engines are not expecting it.

I've considered using a single chip linear audio power amp and a simple transformer in the past.

This is because custom wound transformers are so expensive and diy hand wound won't do for high rel use (project is a survey drone) .