A time delay relay is a relay that stays on for a certain amount of time once activated. This time delay relay is made up of a simple adjustable timer circuit which controls the actual relay. The time is adjustable from 0 to about 20 seconds with the parts specified. The current capacity of the circuit is only limited by what kind of relay you decide to use.
Time Delay Relay Schematic
SchematicParts
Part
Total Qty.
Description
Substitutions
R1 1 1 Meg Pot
R2 1 10 K 1/4 Watt Resistor
C1 1 10uf 25V Electrolytic Capacitor
C2 1 0.01uf Ceramic Disc Capacitor
D1,D2 2 1N914 Diodes
U1 1 555 Timer IC
RELAY 1 9V Relay
S1 1 1A 120V SPST Switch
MISC 1 Board, Wire, Socket For U1