Simple tester checks Christmas-tree lights


Posted on May 11, 2012

Why is it that you always test 48 bulbs before you find the bad one in a 50-light string? The simple circuit in Figure 1 allows you to divide and conquer, greatly reducing the time it takes to find the bad bulb. The circuit uses a pair of NE2 neon bulbs with current-limiting resistors. You can use a pair of Radio Shack 272-1100 bulb-resistor sets. It`s convenient to house the tester in a clear piece of plastic tubing, with the probe tip emerging from one end and a light-duty power cord emerging from the other end.






Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

IR Remote Control Transmitter ATtiny28
Complementary-output-variable-frequency-inverter
Sonic Kaleidoscope Circuit
M66T Melody Generator diagram
Make this Astable Multivibrator Blinker Circuit Using NAND Gates
noise canceller
Nine-digit password composed of the controller circuit diagram CD4017



Top