Timed Night Light Essentials
www.kitronik.co.uk/2139
Now you must attach the battery clip. It needs to be connected to the terminals marked ‘Power’.
The red lead should be soldered to the ‘+’ terminal also marked ‘red’ and the black lead should be
soldered to the ‘-’ terminal also marked ‘black’. Connect the PP3 snap on to the 3xAA battery box.
Do not use a 9V battery with this circuit.
Checking Your Circuit
Check the following before you connect power to the board:
Check the bottom of the board to ensure that:
All the leads are soldered.
Pins next to each other are not soldered together.
Check the top of the board to ensure that:
The body of the four FETs matches the outline on the PCB.
The flat edge on the LED lines matches the outline on the PCB.
The red wire on the power clip goes to the connection marked ‘red’ and the black wire to the connection marked
‘black’.
R1 & R7 are 10K resistors (brown, black, orange colour bands).
R5 is a 47 resistor (yellow, purple, black colour bands).
R2 has 220K printed on the side.
Testing the PCB
Set the duration to min – fully anti-clockwise.
Set the light level so that it points at the other trimmer.
Power the board up and cover the LDR – the LED should turn on for about five seconds. Uncover the LDR, then cover
it again, the LED should turn on again for about five seconds. The duration and light level can be adjusted.
If the circuit doesn’t function as expected, use the fault finding flow chart to locate the problem.
ATTACH THE BATTERY CONNECTOR
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