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Rapid fire — Parallax Forums

Rapid fire

Rob311Rob311 Posts: 83
edited 2006-04-08 07:03 in General Discussion
I want to be able to turn on and off an electric device rather fast, .25-5 seconds.
Im looking for somethign along the lines of a relay that once powered will turn on and off realy quick, almost like a strob light.
Any sugestions?

Comments

  • Paul Sr.Paul Sr. Posts: 435
    edited 2006-04-06 18:11
    Motor with a cam - lobe hits/closes contact.
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2006-04-06 18:45
    What's the application?
    pwssr's idea is interesting -- sort of a Gattling gun effect
  • Rob311Rob311 Posts: 83
    edited 2006-04-06 23:29
    HA HA HA gattling gun is right!
    im looking to have a solenoid fire quickly, its sort of hammering a nail into a board.
  • Tim-MTim-M Posts: 522
    edited 2006-04-06 23:41
    How about a simple push button activiated·555 timer to output a pulse train that, via relay or transistor,·fires your solenoid?· Your output could be adjustable that way, to set the 'rapid-fire' rate at the speed you'd like.· Or, this could all be Basic Stamp driven and be more versitile yet!

    Tim
  • Rob311Rob311 Posts: 83
    edited 2006-04-06 23:44
    I will have to look into the 555 timer... any idea how to wire it? never used one b4...
    And as to the basic stamp idea, I was forced to throw that one out due to its price.
    ...actuly my original idea was to use a stamp and multiple solinoids, pull out the mechanisim that holds the pushing peice in the solinoid and line them up. then i could time the diffrent solinoids and the one rod would fire throu all of them, sort of a rail gun... but that was also thrown out do to pricing.. lol
  • Tim-MTim-M Posts: 522
    edited 2006-04-07 00:31
    OK, here is a link to get you started with 555 timers:

    http://home.cogeco.ca/~rpaisley4/LM555.html

    Take a look at the 555 calculator link at number three to calculate the resistor and capacitor values to give you the speed you want.· You should be able to put your circuit together for only a couple of dollars... 20-80 cents for the 555 timer, pennies for the resistors and capacitors, then a MOSFET transistor on the output of the timer, and your other misc. stuff like the push button.

    Tim
  • Rob311Rob311 Posts: 83
    edited 2006-04-07 01:57
    wow that pretty cool
    1 more question, at no point does it comment on the voltage of the capacitors, only the charge... does it matteR?
  • Tim-MTim-M Posts: 522
    edited 2006-04-07 15:40
    Yep, it matters. Capacitor voltage rating needs to be at least a minimum of the highest voltage that the cap will 'see', and it's nice to see it slightly higher for peace of mind 'headroom'. Higher voltage rating doesn't particularly matter. I find it easy for most simple dc circuits to use the supply voltage, rate above that for nearly all or all caps, and go from there.

    Tim
  • SteveWSteveW Posts: 246
    edited 2006-04-07 15:46
    > I find it easy for most simple dc circuits to use the supply voltage, rate above that for nearly all or all caps, and go from there.

    Except for Tantalum capacitors used as supply decouplers, where twice the supply voltage is a reasonable starting point, especially if they can ever see sharp voltage rises (power turned on by a switch / plug, rather than a voltage regulator or switch mode power supply, where the voltage rises (relatively) slowly.)

    Steve
  • Tim-MTim-M Posts: 522
    edited 2006-04-07 16:46
    Good point Steve. Wow, I missed that - wasn't thinking power supplies at the time!

    Thanks,

    Tim
  • Rob311Rob311 Posts: 83
    edited 2006-04-08 01:02
    thank you nice people
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2006-04-08 07:03
    Why not a BS-1. After all, it is programable.

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