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Step 5Build/ Test your power supply
If you are building a power supply please see the schematic/ parts list below. This design worked fine for me. Thanks Tim!
If you were lucky enough to find a wall wart power supply lying around, also test that it is working but wait to dismantle it because it might be more convenient to keep it in its plastic housing depending on how small it is.
Below I soldered the two leads of my transformer to each side of the power track. The secondary coil, or leads with lower voltage, are then piped into the rectifier and regulator setup.
Read on if you want to learn a little about how a power supply works:
AC to DC power supplies do 4 incredibly important things in those tiny, ugly, black boxes.
1. They step down your high 120VAC (for US) to a reasonable number, in our case between 6 and 12 ideally.
2. A cooperation of diodes (electrical one way valves) forces this stepped down AC current into a very sloppy DC current so that our small DC electronics can use it! This is also called a rectifier and can be bought as a separate component.
3. Capacitors smooth this bumpy current.
4. A voltage regulator or zener diode trims whatever small, slightly bumpy, DC voltage you now have down to a much smoother and lower voltage current.
Schematic
Parts list for +5v power supply
- 1 Transformer, 120VAC to 6-12 VDC
- 4 1N4001 Diodes
- 1 470uF Electrolytic Capacitor
- 2 .1uF 100VDC Metal Poly Capacitors
- 1 LM7805 Voltage Regulator
If you were lucky enough to find a wall wart power supply lying around, also test that it is working but wait to dismantle it because it might be more convenient to keep it in its plastic housing depending on how small it is.
Below I soldered the two leads of my transformer to each side of the power track. The secondary coil, or leads with lower voltage, are then piped into the rectifier and regulator setup.
Read on if you want to learn a little about how a power supply works:
AC to DC power supplies do 4 incredibly important things in those tiny, ugly, black boxes.
1. They step down your high 120VAC (for US) to a reasonable number, in our case between 6 and 12 ideally.
2. A cooperation of diodes (electrical one way valves) forces this stepped down AC current into a very sloppy DC current so that our small DC electronics can use it! This is also called a rectifier and can be bought as a separate component.
3. Capacitors smooth this bumpy current.
4. A voltage regulator or zener diode trims whatever small, slightly bumpy, DC voltage you now have down to a much smoother and lower voltage current.
Schematic
Parts list for +5v power supply
- 1 Transformer, 120VAC to 6-12 VDC
- 4 1N4001 Diodes
- 1 470uF Electrolytic Capacitor
- 2 .1uF 100VDC Metal Poly Capacitors
- 1 LM7805 Voltage Regulator
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