Time Delay Relay-2
-
When activated by pressing a button, this time delay relay will activate a load after a specified amount of time. This time is adjustable to whatever you want simply by changing the value of a resistor and/or capacitor. The current capacity of the circuit is only limited by what kind of relay you decide to use.
Schematic
Parts:
|
Part |
Total Qty. |
Description |
Substitutions |
|
C1 |
1 |
See Notes |
|
|
R1 |
1 |
See Notes |
|
|
D1 |
1 |
1N914 Diode |
|
|
U1 |
1 |
4011 CMOS NAND Gate IC |
|
|
K1 |
1 |
6V Relay |
|
|
S1 |
1 |
Normally Open Push Button Switch |
|
|
MISC |
1 |
Board, Wire, Socket For U1 |
Notes:
1. Email jawaharlal@excite.com with comments, questions, etc.
2. To calculate the time delay, use the equation R1 * C1 * 0.85=T, where R1 is the value of R1 in Ohms, C1 is the value of C1 in uF, and T is the time delay in seconds.
3. S1 may be replaced with an NPN transistor so the circuit can be triggered by a computer, other circuits, etc.
4. Most any 6V relay will work for K1. If you use a large relay, you my need to add a transistor to the output of the circuit in order to drive the larger load.