SIMPLE SWITCH TIME DELAY CIRCUIT DIAGRAM This Switch On Time Delay circuit should work with most any 12 volt DC relay that has a coil re...

SIMPLE SWITCH-OFF TIME DELAY SCHEMATIC DIAGRAM The two circuits di atas illustrate opening a relay contact a short time after the igniti...

SMOKE DETECTOR CIRCUIT USING LDR SCHEMATIC DIAGRAM When there is no smoke the light from the bulb will be directly falling on the LDR.Th...

SOUND LEVEL (DECIBEL) METER CIRCUIT SCHEMATIC DIAGRAM In operation, with no input, the DC voltage at pins 1,2 and 3 of the op-amp will b...

TRANSISTOR TESTER CIRCUIT DIAGRAM Circuit operation is as follows. The 555 timer is set up as a multi-vibrator 12hz. The output on pin 3 dr...