Hand Crank Generator

Here is the circuit of a compact hand powered generator that can awake little electronics by hand crank. This is a great vacation device that you can rely on to operate your small electronics. The prototype generates up to near 150mA of current at 5 volts, enough for a wide range of minuscule devices!

It is easy to use a small dc motor as the “dynamo” of a hand crank generator, but mechanical construction of the associated “gear-train” unit is an awkward task. That is why an easy method is used here. In this project, a commonly available 5V DC plastic gear robot motor forms the heart of the power generator. A 60mm dia robot wheel, fitted with a 40mm long pcb stud, works as the crank shaft.

Hand crank generator

Basic circuit diagram of the Hand Crank Generator is shown below. Diode D1 (1N5819/1N4007) is used for input polarity protection. While cranking, about 5 VDC available across the output terminals is stored by the super capacitor C1 (1F/5.5V) for a finite duration. If the output is not available while cranking the motor in clockwise direction, just reverse the connection of the motor wires at the input of the circuit.

Hand crank generator circuit


  • M1: 5VDC Plastic Gear Robot Motor
  • D1: 1N5819/1N4007
  • C1: 1F/5.5V Super Capacitor

The “raw” output available from this circuit can be used in a number of ways. At first, a zener-diode based 5.1 V regulator circuit is connected to the prototype to get a stable (low current) 5.1VDC supply. It’s fine!

Hand crank 5V generator


  • C2: 100nF
  • R1: 47 Ω¼ W
  • ZD1: 5.1V ½ W

Lab Note

  • Prototype was also tested with 1N4007 as D1, and 2200uF/25V electrolytic capacitor as C1. However, for better efficiency try to use 1N5819 as D1 and the 1F/5.5V super capacitor as D1
  • The raw ouput can be processed to get a stable 5V (or 3.3V) with the help of a lowdrop voltage regulator like LM 1117-5.0 ( LM1117-3.3) available in SOT-223 package. Tested application circuit is shown below

Hand crank 33V generator

Componets bought from

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