Programmable Cyclic Set On-Off Timer With Relay Output

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This project is to build cyclic on-off programmable timer. In this project user can set ON timer and Off time using keys and 7 segment display. Relay is provided as output, where relay will be remained ON for ON time and it will goes OFF after ON time overs. And Relay will remain Off till Off time overs.

We Requires 4 keys for operation like Change digit, shift digit and start and stop timer.

Step 1: Component Required

Components required are as follows for the project as Follows

1 x PIC16F876A
1 x PIC Dev Board

4 x Keys

4 x 7 Segment Common Cathod or Common Anode

+5v Power Supply

4 x BC547 Transistor

I have used Common cathode 7 segment along with NPN transistor.

Step 2: Operation

Set the set timer using keys and display.
Use menu key to enter into options and set the ON time and Off time.

After that Start the timer, Timer will be running continue.

Here is small video of the operation of the project:

Step 3: Schematic

Here is schematic of complete project:

Step 4: Executable File

please find executable in following path



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    4 Discussions


    3 months ago

    Do you have a schematic or connection diagram perhaps?

    2 replies

    Reply 3 months ago

    please find the schematic in the steps. I have updated the schematic.


    3 months ago on Step 2

    Recently i have added blinking as well