??? 03/04/04 11:59 Read: times |
#65925 - RE: Solenoid operated Pneumatic valves Responding to: ???'s previous message |
Sounds like you got the common problems covered. The optos between the micro and the uln2803 driving the relay is probably a bit excessive. The average industrial PLC has optos on the inputs but none on the outputs. The usual diode across the relay coil is usually sufficient - unless the relay is a big one!
You'll probably also find the solid state relays will work fine also - make sure they're zero volt switching (most are) as these will turn on or off only on a zero crossing of the mains. |