Time Delay Relay II
Electronic Schematics > Miscellaneous > Time Delay Relay II

By jawaharlal@excite.com

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 for Time Delay Relay


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  


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.

Title: Time Delay Relay II
electronic circuit
Source: www.aaroncake.net/circuits/
Published on: 2005-02-10
Reads: 826
Print version: Print version

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Electronic circuits > Miscellaneous > Time Delay Relay II