This circuit can be used as an amplifier for musical instruments or even with your cell phone. The circuit is old and was found in the 1990 edition of Radio Electronics Experimenter magazine.
By pressing and releasing PB1, only one LED is lit, drawing a number from 1 to 6, as in a die. The...
We found this circuit in the National Semiconductor Linear Applications Handbook of 1994. The...
The transformer inf this circuit is a 6 or 9 V unit and diodes 1N4002. The filter capacitor is 2...