Monday, April 2, 2018

Circuit Schematic Simplest Automatic Solar Light from Water Bottle

Robometricschool. - This is one of the best solar cell application for you to build a project of simple solar light from water bottle in this time. The main component to build this project are solar cells and trnasistors.

Circuit Schematic

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Component Parts

  • D1 = 1N4007____1000V 1A Diodes
  • D2 = 1N4148____75V 150mA Diodes
  • Q1,Q2_____2N2222____75V 0.6A TO-18 NPN transistor
  • R1,R2___1K 0.25W Resistors
  • LED1_____LED RED
  • Solar cell 3.3V-3.6V 100mA
  • 1.2V x 2 AA batteries 500mAh


This is Circuit Schematic Simplest Automatic Solar Light from Water Bottle for you. Accordingly Eleccircuit that published this project describe that this is simplest automatic solar LED light circuit that my son try to make it for basic small solar charger. This circuit is a simplest circuit. He trial it to learn about solar LED light, and makes it all by himself. He needs one LED light that brightest at night. But in daytimes it will go out and charged current to battery.

We can choose to use 2 x AA nickel-metal hydride battery total voltage is 2.4V at 500mAh. It need to used current about 50mA – 80mA. Thus he cannot use a white LED because it use 3.3-3.6V.

As this solar LED garden lights circuit. We use the relay to control current because it’s easy. But Relay works by Coil which use high current about 80mA. The solar cell have 100mA only so cannot use both the relay and to charge the battery.

Thus, I choose to use transistors instead relay, until is the circuit as Figure 1. The small base-emitter current controls the larger collector-emitter current.


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