Connect with us

Power from RS-232

Discussion in 'General Electronics Discussion' started by Wox, Sep 4, 2012.

  1. Wox

    Wox

    2
    0
    Sep 4, 2012
    I'm trying to connect this laser sensor to an RS-232 port: link

    I should connect TxD to RxD (DB9 pin 2) and RxD to TxD (DB9 pin 3), but what pins should I connect the "0V" and "+Vs" lines to? As far as I understand, connecting these lines provides power to the laser. According to the laser specs:
    voltage supply range +Vs: 12 ... 28 VDC
    current consumption max. (no load) 80 mA

    Can an RS-232 port handle this and if yes, which pins should I connect "0V" and "+Vs" to?

    Thanks.
     
  2. KrisBlueNZ

    KrisBlueNZ Sadly passed away in 2015

    8,393
    1,266
    Nov 28, 2011
    No. A normal RS-232 port doesn't provide a power supply output; it only has data and flow control outputs, and you can't draw 80 mA from them.

    I'd suggest you use a wall wart (power supply) that can supply 12V at half an amp or so. You might want to cut the plug off it, and run the wires straight into one of the data connectors, to keep things tidy.
     
  3. Wox

    Wox

    2
    0
    Sep 4, 2012
    Ok, thanks. Just out of interest, isn't there any way to draw power from a RS-232 port, even not just a few mamp?
     
  4. KrisBlueNZ

    KrisBlueNZ Sadly passed away in 2015

    8,393
    1,266
    Nov 28, 2011
    Yes, you can draw a few milliamps from the signal and/or flow control outputs. But not 80 mA.
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-