Fog Control
Here is the schematic:
Here is the software
Parts list:
- 3 - 1k ohm 1/4 or 1/2 watt resistors
- 1 - NPN switching transistor
- 1 - relay
- 1 - rectifier diode (1NX001 type)
- 1 - DB-25 male sub-d connector
Notes:
The transistor does need to be able to handle the current and voltage of the
relay. The small 2N2222 transistors work for smaller relays but blow out
on bigger ones.
The voltage on the relay driver needs to be enough to drive the relay.
(ie 5v relay, 5v power supply).
The +5 power on the switches needs to only be 5volts. If this is any higher
you will ruin your parallel port. You have been warned.
All grounds need to be tied together. This may feal counter intuitive but
needs to be done for the circuit to work properly.
The input switches can be anything. An AC relay switching the power to the
parrallel port (The from fog Machine).