Wanted: Free or inexpensive educational material


Thread Starter

Bill Newton

Greetings Smart Masses,

I was wondering if anyone could point me in the right direction. I'm looking for a good source of free (or close to free) relay logic based educational material. Not all the parts of our process are networked together and are also not managed by a plc. I need to make a "snooze alarm" out of 2 on delay timers and 2 regular relays. The L1 power is provided when a low level alarm is made. The FN controller doesn't offer a "repeat alarm" function and once it is silenced the operator leaves it to run out of material. I want to make the alarm continue periodically until the low level alarm is no longer true. My problem is in my head when I try to draw it out everything is happening at once and I can't seem to make it make sense on paper. I would greatly appreciate your assistance on these matters.