SST-01 The softstart for toroidal transformers

Picture of the pcb. The pcb is doublesided with plated through holes and the copper is extra thick.


As you can see at the picture the pcb will be at mains potential and therefore lethal. You must ensure that this pcb is well protected against unintentional touching. All parts are dangerous to touch when the mains is switched on.

Do you have an amplifier with a toroid, 500 VA or more? Do you have problems with burned fuses in the wall? Maybe you also are having trouble with mains switches which don't last long. Maybe this soft start circuit may be something for you. It's easy to build and it's virtually impossible to burn the traces. The pcb has 95 um (2.7 oz.) copper and is double sided with a professional look and quality.

Interesting features:

  1. Fast reset time.
  2. Consumes very little power.
  3. Very thick copper traces, virtually impossible to burn off.
  4. No need for high current rating of the mains switch.