| The +/- 12 Vdc supply was needed for our add on circuits. The soft turn on timer also needed + 12 V. The circuit is farely simple with the 1000 uf capacitor the regulator and the 100 uf capacitor. Just remember to put the caps in backwards for the negetive voltage. The regulators are the 7812 for + 12 V and 7912 for -12V. The transformer I used was purchesed from MCM. It is a center taped 40 VA 2 amp transformer. |
