Connect with us

Tool-activated vacuum

Discussion in 'General Electronics Discussion' started by jamesho, Apr 1, 2017.

Scroll to continue with content
  1. jamesho

    jamesho

    2
    0
    Apr 1, 2017
    Hi

    I'm trying to make a tool-activated (chop saw) vacuum cleaner, and I'm haveing a few issues that i hope one of you fine people may be able to correct me.

    I'm using this circuit
    https://cdn.instructables.com/FHS/MUSM/GZHJZI61/FHSMUSMGZHJZI61.LARGE.gif

    And a solid state relay, a Fatek SSR-25AA.

    I have built and it part works.
    Switching on the saw, the vacuum starts. However, the saw does not work.
    The relay LED illumates when the saw is switched, but it's just doesn't spin up. I've confirmed the saw is good, by powering separately.

    Any help would be appreciated.
    James
     
  2. davenn

    davenn Moderator

    13,813
    1,945
    Sep 5, 2009
    yes, that's right, because you cannot power the saw in series with the relay

    MOST stuff on instructables www site is crap, garbage, waste of computer and internet space

    I assume you mean Fotek ... I can find no reference to Fatek

    presumably this is the relay you have ? note the input and output voltage ratings

    ssr.jpg


    Dave
     
  3. jamesho

    jamesho

    2
    0
    Apr 1, 2017
    Fotek is the one...
    Thanks for confirming I cannot power the saw in series with the relay.
    The voltage on the relay look the same.
    80-250VAC input, 24-380VAC
    Is than an issue, both input and switched are 240V?

    If I cannot power the saw in series, any pointers how i can make a tool-activated vacuum?

    Thanks
    J
     
  4. davenn

    davenn Moderator

    13,813
    1,945
    Sep 5, 2009
    the problem is you cannot draw the current required by the saw through the relay circuitry

    you need additional circuitry
    the power switch for the saw needs additional contacts so that it also switches power to the relay input
     
  5. duke37

    duke37

    5,364
    771
    Jan 9, 2011
    A current relay could be used where a high current instead of a high voltage is used to pull the relay in.
    Alternatively, a current transformer with the saw current passing through the primary and the secondary connected to a load resistor and the SSR.
    I think that devices similar to what you want are available but do not know where to find them.
     
  6. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,491
    2,833
    Jan 21, 2010
    Google "green power board" They typically have one or two outlets which turn on the others when power is drawn. You'll need to check that these can switch your load safely, but they're a ready-made option that doesn't require fooling with mains voltages.

    Incidentally, that instructable seems to use a current relay, although I have little doubt that this is either not mentioned or is buried somewhere. A link to the actual instructable would help, but only to confirm stuff we already know (either about the circuit or instructables themselves).
     
  7. KMoffett

    KMoffett

    723
    75
    Jan 21, 2009
    Did I miss something? Why not a 240VAC relay in parallel with the saw? Use the contacts to switch the vacuum on and off with the saw switch.

    Ken
     
  8. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,491
    2,833
    Jan 21, 2010
    I guess because it needs to be after the power switch for the saw. Otherwise the vacuum will be powered whenever the saw is powered. And you might as well just power them from the same outlet -- no relay required at all.
     
  9. KMoffett

    KMoffett

    723
    75
    Jan 21, 2009
    Many years ago I had that problem.But starting the saw and the vacuum at the same time would trip the breaker in the panel. I made a circuit that sensed the saw current and delayed the start of the vacuum by an adjustable delay of a couple of seconds. I also added an adjustable delay after the saw stopped before the vacuum shut down. Caught the dust while the blade was spinning down. And a switch to select the automatic start/stop or run the vacuum by itself. Posted on an electronics group. Months later this what appeared on the market: https://www.woodcraft.com/products/...acuum-switch?gclid=CPKa8vTehdMCFZC4wAodNr8ELQ Can't believe it was a total coincidence. But, they marketed it and I didn't. Also made a knee switch, with an added lightweight remote start/stop pendent on a coil cord. And clip the attach it to my belt or shirt. This would allow me the hold up the near end of an 8-foot board to be ripped, without having to hold it and reach for the knee switch 6 feet away.

    Ken
     
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

-