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Driving a 120V solenoid (or two) — Parallax Forums

Driving a 120V solenoid (or two)

Nightrider7731Nightrider7731 Posts: 46
edited 2005-01-20 17:05 in BASIC Stamp
Disclaimer:· BS2 noob

I'm trying to prototype driving two 120V ASCO solenoids using a BS2.· Where would I go to find the specs on a transistor that could handle this load, or would this be better handled by a relay of some type?· Feel free to drop part #s for reference.

TIA

Comments

  • Jon WilliamsJon Williams Posts: 6,491
    edited 2005-01-05 20:43
    You might want to use an SSR (solid state relay). Checkout the Opto-22 web site (www.opto22.com)

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    Jon Williams
    Applications Engineer, Parallax
    Dallas, TX· USA
  • Eric REric R Posts: 225
    edited 2005-01-07 05:02
    Be sure to check ebay when you find the model number you are looking for. I picked up a variety·SSR's at a good price last fall.

    I have used Crydom·with good results, model # D2W203F and SDV2415.

    Good Luck!
    ·
  • Alan BradfordAlan Bradford Posts: 172
    edited 2005-01-10 00:13
    Hi,

    I use the Opto-22 OAC-5 and Grayhill Mini·modules to drive ASCO valves. The Grayhill number is 70M-OAC5

    The small ASCO Valves (1 inch pipe and smaller) can be safely driven with these Modules. I actually drive 3 valves with one module.· The valves draw about 100-200 MA and the SS's are rated for 3 Amps. I never drive the SSR's more than 50% (1.5 amps). I have never had a failure with one yet. Some of my systems have 30 of these valves run from one Stamp.

    Hope this helps you,

    Alan Bradford

    Plasma Technologies
  • Nightrider7731Nightrider7731 Posts: 46
    edited 2005-01-10 15:11
    Thanks for the updates and info!· The valves are 3/4" and they all will be independantly controlled, so I'm definitely in the green for loads.· And I've already been watching eBay!

    ·
  • Nightrider7731Nightrider7731 Posts: 46
    edited 2005-01-18 20:34
    I've been looking for some SSRs for my project on eBay and I was wondering if a 240V relay (w/ a 3-24v control) could also handle a 120V supply·or are there some internals that need the 240V supply.

    TIA·
  • Alan BradfordAlan Bradford Posts: 172
    edited 2005-01-18 22:00
    Hi,

    Usually the voltage rating is the maximum that the relay can handle. I will not say that is true 100% without knowing the type of SSR you are interested, but that is·what is typical. If you look at the spec sheet it will say the range (60-240 VAC or something·like that)

    Alan Bradford

    Plasma Technologies
  • pvalepvale Posts: 8
    edited 2005-01-19 01:24
    I have some 240V, 25A SSRs in service right now that are handling 120V loads. I don't think they run as hot on the lowered voltage. One of them is handling nearly 20A. Be sure to heatsink your SSRs well, or their lifetime will be short. I don't know if the lowered voltage thing is universal but these relays are Crydom D series, zero-crossing turn on/off.
  • Nightrider7731Nightrider7731 Posts: 46
    edited 2005-01-20 16:59
    Is there a benefit, or preference, to driving·an SSR by a transitor rather than directly from a pin?· It would seem like a good practice, but I'm no EE.

    TIA for all the valuable suggestions this forum provides!
  • Jon WilliamsJon Williams Posts: 6,491
    edited 2005-01-20 17:05
    You'll need to check the specs on the SSR. There are those that are capable of being driven directly from a TTL source.

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    Jon Williams
    Applications Engineer, Parallax
    Dallas, TX· USA
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