Author Topic: OPTO-COUPLER INTERFACED WITH PLC  (Read 12460 times)


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« on: October 28, 2014, 08:36:17 AM »
Im working on a school project and im new to electronics, on my project im using PLC S7-200 SIEMENS and its got 24VDC output but I want my PLC to driver a motor driver circuit and the circuit takes 5VDC on its input. So I decided to use an opto-coupler to isolate the 24VDC frm my PLC to 5VDC motor driver circuit. My problem is on choosing the type of opto-coupler(phototransitor type) which can take 24V on the input side. Can anyone help me with the opto-coupler which can take 24V tht I can use. The one I've seen is a 4N25-28 series, on their data sheets I only see the Voltage - Output (Max) which is 70V and Voltage - Forward (Vf) is 1.3V, so im not sure if this 1.3Vf is the minimum voltage the can be supplied on the input side or what.  Can someone clear me or help on this problem