USE YOUR OLD PC AS AN ELECTRICAL TIMER

Last Update: August 26, 2002

To use the PC as an electrical timer, you can choose a very very old PC that can run DOS is sufficient.

Software:

DOS v6.22 or Windows 98 running in command mode
RELAY.EXE - to output a hex byte to the parallel port.
WAITFOR.EXE - to wait until a specified time.
DELAY.EXE - to wait for a specified number of seconds.
Download these files.
Detail documentation of these utilities.

Methods:

1. Build a circuit to turn on the relay from the PC printer port.  Here is a link about parallel port.

Parallel port pin 2 - Data bit 0
Parallel port pin 3 - Data bit 1
Parallel port pin 4 - Data bit 2
Parallel port pin 5 - Data bit 3
Parallel port pin 6 - Data bit 4
Parallel port pin 7 - Data bit 5
Parallel port pin 8 - Data bit 6
Parallel port pin 9 - Data bit 7

2. Write a batch file to use the software to program your timer.

　

BACK TO MY HOME PAGE