5v Regulated Solar Power Supply Circuit

The circuit consists of an oscillator transistor and a regulator transistor.
The solar panel charges the battery when sunlight is bright enough to produce a voltage above 1.9v. A diode is required between the panel and the battery as it leaks about 1mA from the battery when it is not illuminated.
The regulator transistor is designed to limit the output voltage to 5v. This voltage will be maintained over the capability of the circuit, which is about 10mA.
The oscillator transistor must be a high-current type as is is turned on for a very short period of time to saturate the core of the transformer.
This energy is then released as a high-voltage pulse.
These pulses are then passed to the electrolytic and appear as a 5v supply with a capability of about 10mA. If the current is increased to 15mA, the voltage drops to about 4v.
The transformer is wired so that it gives POSITIVE feedback.
The transistor turns on via the 1k resistor and this produces expanding flux in the core.
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Read More Source :
http://www.talkingelectronics.com/projects/
PowerSupply5vSolar/PowerSupply5vSolar.html
Thank you.

This entry was posted on Friday, July 27th, 2007 at 2:07 pm and is filed under Automotive, Power supply, switching power supply. You can follow any responses to this entry through the RSS 2.0 feed.