Saturday, April 6, 2013

Nestbox Solar Powered Wireless CCTV Camera Circuit

Below is the circuit used to power the CCTV camera, provide lighting
inside the nestbox, and charge batteries from a PV solar panel.

Circuit diagram for CCTV powered by Solar Panel with Battery Backup

D1 is a Schottky Diode used to prevent battery charge escaping through
the solar panel at night. Something like a 1N5817 (1 Amp 20 Volt diode)
will do the job and it has a very low voltage drop of under 0.45
Volts. D2 and D3 are ultrabright LEDs used to illuminate the inside of
the nestbox. R3 and R4 are resistors chosen (400 Ohms) to ensure that
no more than 30mA of current gets to the sensitive LEDs, with R5 (a 10k
variable resistor) used to increase the resistance and therefore dim
the LED s if they are too bright.The LM317T is a voltage regulator *
used to bring the voltage of the solar panel and batteries down to just
over 8 volts using resistors R1 (270 Ohm) and R2 (1500 Ohm) to set
this value. K is the wireless CCTV camera. A switch (not labelled) is
used to manually turn the camera on and off as required.