Showing posts with label LM317. Show all posts
Showing posts with label LM317. Show all posts

16 August, 2012

Transformerless tube power supply

In 2012 bulky power transformers that work directly from the power grid at 50/60 Hz have mostly disappeared. My objective here is to modernize the power supply for a one-tube transmitter in the same way.

The circuit is based on an electronic transformer for LED or halogen lamps. Electronic transformers usually have a minimum power rating, below which they will not start. This one can tolerate a lower load than most and gives out 12 Volts for a load from less than 10 W and up to 60 W.