Temperature switch project kit

This kit is available in two variations, this is the temperature activated version or light activated switch is available. The output of the board can be used to control other electronic circuits, turning them on automatically when it goes light, dark, hot or cold.

The board has space for an LED with current limit resistor (both available separately) which will light when the output turns on. The Darlington pair transistor configuration allows an output current of up to ½ an amp to be controlled. Operating voltage 3V to 10V (lower voltages allow for better adjustment of the switching point).

Possible applications include:

• Garden light that switches on automatically at night
• Draw alarm, which sound when a dark draw is opened
• Line following robot (using 2 light activated boards)
• Babies bath over temperature indicator
• Automatic fan

See ldr_temp.pdf for an application note detailing these projects.

Kit contents:

• 1 x 47Kohm potentiometer
• 2 x BC337 NPN transistors
• 1 x thermistor
• 1 x 220ohm resistor
• 1 x heat activated switch PCB

PCB dimensions: 53mm x 25.5mm.