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Need help designing multiple voltage and current output from single input

  1. Feb 13, 2012 #1

    I am in the process of designing a voice activate control system for my truck for various things like wiper motors/windows/etc.

    The development board I am using will have up to 20 outputs @ either 5 or 12V DC around 10mA. However, this is not strong enough to drive a wiper motor or a couple of the various controls I need.

    I was looking into building my own powersupply/converter that I can take some of these inputs with, and be able to have several outputs such as 5V 12V DC & 12V AC and a couple different current ratings depending what each output requires. I could use the car battery as an input/reference power.

    Could you guide me in the right direction to finding base circuit diagrams/parts that I would need to go off of.

  2. jcsd
  3. Feb 13, 2012 #2
    Sorry I didn't make the title clear and could sound confusing.

    I need to convert a single 5V 10mA source to one of the mentioned outputs above. I will need to replicate this for each of my outputs (up to 20) and several of them may require a different output (25mA, or 200mA.., either 12V AC or 5V DC..etc) but this output can only be provided once the individual input source of 5V DC @ 10mA is set high.

    Each output will require its own circuit/design so this doesn't have to be designed as one usit, I don't mind building a small box for each one.

    Hope that clears things up
  4. Feb 15, 2012 #3
    bump, anyone able to point me in the right direction?
  5. Feb 15, 2012 #4

    jim hardy

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    Science Advisor
    Gold Member

    its not clear what you'll need AC for.

    But 10 miliamps at 12 volts could drive a small relay or a buffer that'd drive a bigger relay.

    I use 555 as a buffer, its basic version (not 555C) has stout output that should handle an automotive relay.
    Those automotive relays you can get cheap at any junkyard go pull them out of an old car's under the hood electrical box...
    tie TRIG and THRESH together and use for input, output on non-cmos version is good for 100 ma.

    discovercircuits dot com has a friendly hobbyist forum, you'll find folks to help with making schematics and circuit boards and precautions like "flywheel diode" and "bypass capacitor".
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