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PLC 24V PWM Output to 5V PWM microcontroller logic 1

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krzesniak1

Electrical
May 22, 2015
2
Hello,
I have a problem with conversion 24V PWM (up to 5kHz) signal (PLC output signal 0.5A) to 5V PWM H-bridge (logic input 10mA). I have an idea to make a voltage divider (serial resistors connection 1,9k and 500R), so i have 19V and 5V and 10mA. Would it be sufficient? Is it a good idea? Or maybe should I use some optocoupler or RS-232 to TTL interface? Does anyone faced with such a problem? I would be grateful for help and advice :)
 
 http://files.engineering.com/getfile.aspx?folder=7d9611ae-450d-4d8e-beb2-2c6d25992154&file=voltage_divider.tiff
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Typically in dealing with 5v, you are dealing with solid state circuits, and therefor TTL interface would be best (speed and reliability).

Don
BIN Industrial & PLC Training
 
Thank you for respond! Could you tell me, if the MC1489 or the SN75189 inverter would be a good choice?
 
RS232 to TTL why??

Here is the answer for you.

Opto cuppler is a great idea

Use the FODM124 of Fairchild . connect 2 K ohms between the input diode anode and the 24v PWM
Connect the output collector via 2 K ohms to the 5 V and the Transistor Collector to the Logic input.

Any question forward to : daveross10 at gmail dat com

Good luck
 
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