How to Make a Voltage Multiplier With Diodes & Capacitors

Diodes and capacitors can be used to build a simple voltage multiplier.

A voltage multiplier is an electrical circuit used to convert AC voltage to a higher level DC voltage. The output of the multiplier is generally an integer multiple of the AC peak voltage (Vpeak). For example, one can theoretically generate 220 VDC from 110 Vpeak AC. This ideal output can be achieved only to a close approximation due to drifts in component values as well as current drawn by the load, which may decrease the output voltage.

Things You'll Need

• A 6-by-6 inch printed circuit board
• A soldering iron
• Solder
• 2 red banana connectors
• 2 black banana connectors
• A permanent marker
• 4 1000 pF unpolarized capacitors
• 4 diodes

Instructions

1. Solder a red and a black banana connector side by side at one end of the circuit board. Keep them apart by at least three to four holes on the board to ensure good isolation. Mark "AC input" near the connectors on the board with a permanent marker.

2. Solder one end of a capacitor to the trace connected to the black banana connector. Solder the other end to another trace not connected to any other component. We will call this Point 1.

3. Connect the positive end of a diode to the trace leading to the red banana connector. We will call this Point 2. Solder the other end of the diode to the trace connected to Point 1.

4. Solder a lead of another capacitor to the trace connected to Point 2. Solder the other end to a trace not connected to any other component. We will call this Point 3.

5. Solder the positive lead of another diode to the lead connected to Point 1. Solder the other end of the diode to the lead connected to Point 3.

6. Connect the positive lead of another diode to the trace connected to Point 3. Solder the other end of the diode to a trace not connected to any other component. We will call this Point 4.

7. Solder another capacitor between Point 1 and Point 4.

8. Solder the positive end of the last diode to the trace connected to Point 4. Solder its other end to a trace not connected to any other component. We will call this Point 5.

9. Solder the last capacitor between Point 3 and Point 5.

10. Solder the second red banana connector to the trace connected to Point 4. Mark "DC out" near the connector on the board with the permanent marker.

11. Solder the second black connector to the trace connected to Point 5.

Tips & Warnings

• This is a times 4 multiplier. That is, a 5 V peak to peak at the input would theoretically give a steady 20 V at the output. The actual output may be lower depending on the load and the precision of the components used.

• Use the soldering iron in a well-ventilated area and be careful when soldering, as the gun gets very hot. Make sure that the components you choose have the appropriate ratings. A 20 V rated capacitor should not be used for an input voltage of 100 V.

References

• All About Circuits: Voltage Multipliers