Linear DC power supply with regulated voltage.
Input is AC voltage (120 Vac rms @ 60 Hz).
Output is smooth DC voltage ( ~3.3 Vdc to 15 Vdc).
Steps:
1. Input is a US wall socket with 120 Vac @ 60 Hz. Transformer with 120:24 turn ratio steps the voltage down to 24 Vac.
2. Blue/Green- Diode bridge rectifier produces a rectified (positive only) voltage.
3. Red - Filter capacitor smooths the rectified waveform into a DC voltage, but leaves some ripples (see the difference between max/min voltages at Red).
4. Orange - Voltage regulator circuit smooths out the ripple and produces clean output voltage (see the smaller difference between max/min voltages at Orange).
Change the pot to vary output voltage from ~3.3 Vdc to 15 Vdc.
Change the filter capacitor value to a smaller value (400 uF) to really see the smoothing power of the voltage regulator circuit.
For more info on how these work:
http://en.m.wikipedia.org/wiki/Power_supply#DC_power_supply
The voltage regulator circuit was designed by N1HFX. See all the great info for this design at: www.rason.org/Projects/discreg/discreg.htm
