simce
Full Member level 4
digital input conditioner
Hi there.
I must design 24 channel digital input card on size of single europa. I need solution that does not use relays that are for 220V where coil is placed as input because there is not enough space for this solution, nor solution with optocupler and current limiter with resistor since this way it will disipate about 0,6Wx26ch=15.6W (led current is 3mA/channel).
I need some other solution (if there exists one)!
Or maybe someone can tell me how this problem is solved in industrial PLC controllers.
Some schematic is also welcomed.
Hi there.
I must design 24 channel digital input card on size of single europa. I need solution that does not use relays that are for 220V where coil is placed as input because there is not enough space for this solution, nor solution with optocupler and current limiter with resistor since this way it will disipate about 0,6Wx26ch=15.6W (led current is 3mA/channel).
I need some other solution (if there exists one)!
Or maybe someone can tell me how this problem is solved in industrial PLC controllers.
Some schematic is also welcomed.