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Sensing RPM on a small gas engine (Briggs&Stratton 8hp)

ArchiverArchiver Posts: 46,084
edited 2002-04-16 14:25 in General Discussion
Hello,

I am wondering if anyone has implemented a rpm sensor for a small
gasoline engine using a stamp? I am in search of a pulse for every
spark of the engine (which occurs every revolution) The engine uses
a standard magneto ignition. All help is greatly appreciated. I
haven't had any luck designing my own [noparse]:([/noparse].


Thanks,
J

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2002-04-15 02:41
    I to am in interested in this. There is a company that sells them for racing
    karts http://www.digatron.cc but they are very expensive. I know that that they
    are using a pickup lead that clips to the sparkplug wire, but I have no idea
    how this works. I think that once you determine how to pick up a signal the rest
    would be easy. Or you could always use a hall effect sensor. Jameco sells a nice
    inexpensive one. Sorry couldnt help more.
    Thanks,
    Jim Gorbet
    jay_mann2000 <jay_mann2000@y...> Hello,

    I am wondering if anyone has implemented a rpm sensor for a small
    gasoline engine using a stamp? I am in search of a pulse for every
    spark of the engine (which occurs every revolution) The engine uses
    a standard magneto ignition. All help is greatly appreciated. I
    haven't had any luck designing my own [noparse]:([/noparse].


    Thanks,
    J


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  • ArchiverArchiver Posts: 46,084
    edited 2002-04-15 04:45
    The pickup is a small coil of wire wrapped around the spark plug lead,
    with one of it's ends tied to ground on the engine. When the plug
    fires, it generates a small pulse of current, which must be amplified &
    conditioned before being sent to the stamp. Pulsein might then be used
    to obtain engine rpm. An amplifier might be as simple as a 4049 CMOS
    inverter chip, or maybe a CMOS schmidt trigger, can't remember the
    number of that.

    HTH,

    Leroy

    Jim Gorbet wrote:
    >
    > I to am in interested in this. There is a company that sells them for racing
    karts http://www.digatron.cc but they are very expensive. I know that that they
    are using a pickup lead that clips to the sparkplug wire, but I have no idea
    how this works. I think that once you determine how to pick up a signal the rest
    would be easy. Or you could always use a hall effect sensor. Jameco sells a nice
    inexpensive one. Sorry couldnt help more.
    > Thanks,
    > Jim Gorbet
    > jay_mann2000 <jay_mann2000@y...> Hello,
    >
    > I am wondering if anyone has implemented a rpm sensor for a small
    > gasoline engine using a stamp? I am in search of a pulse for every
    > spark of the engine (which occurs every revolution) The engine uses
    > a standard magneto ignition. All help is greatly appreciated. I
    > haven't had any luck designing my own [noparse]:([/noparse].
    >
    > Thanks,
    > J
    >
    > To UNSUBSCRIBE, just send mail to:
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    >
    >
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    > Yahoo! Tax Center - online filing with TurboTax
    >
    > [noparse][[/noparse]Non-text portions of this message have been removed]
    >
    > To UNSUBSCRIBE, just send mail to:
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  • ArchiverArchiver Posts: 46,084
    edited 2002-04-15 04:49
    please see:

    http://www.pcbcafe.com/BOOKS/SpiceHandBook/09_chapter08-08.php

    Leroy Hall wrote:
    >
    > The pickup is a small coil of wire wrapped around the spark plug lead,
    > with one of it's ends tied to ground on the engine. When the plug
    > fires, it generates a small pulse of current, which must be amplified &
    > conditioned before being sent to the stamp. Pulsein might then be used
    > to obtain engine rpm. An amplifier might be as simple as a 4049 CMOS
    > inverter chip, or maybe a CMOS schmidt trigger, can't remember the
    > number of that.
    >
    > HTH,
    >
    > Leroy
    >
    > Jim Gorbet wrote:
    > >
    > > I to am in interested in this. There is a company that sells them for
    racing karts http://www.digatron.cc but they are very expensive. I know that
    that they are using a pickup lead that clips to the sparkplug wire, but I have
    no idea how this works. I think that once you determine how to pick up a signal
    the rest would be easy. Or you could always use a hall effect sensor. Jameco
    sells a nice inexpensive one. Sorry couldnt help more.
    > > Thanks,
    > > Jim Gorbet
    > > jay_mann2000 <jay_mann2000@y...> Hello,
    > >
    > > I am wondering if anyone has implemented a rpm sensor for a small
    > > gasoline engine using a stamp? I am in search of a pulse for every
    > > spark of the engine (which occurs every revolution) The engine uses
    > > a standard magneto ignition. All help is greatly appreciated. I
    > > haven't had any luck designing my own [noparse]:([/noparse].
    > >
    > > Thanks,
    > > J
    > >
    > > To UNSUBSCRIBE, just send mail to:
    > > basicstamps-unsubscribe@yahoogroups.com
    > > from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.
    > >
    > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    > >
    > >
    > > Do You Yahoo!?
    > > Yahoo! Tax Center - online filing with TurboTax
    > >
    > > [noparse][[/noparse]Non-text portions of this message have been removed]
    > >
    > > To UNSUBSCRIBE, just send mail to:
    > > basicstamps-unsubscribe@yahoogroups.com
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  • ArchiverArchiver Posts: 46,084
    edited 2002-04-15 09:01
    Leroy,
    I have a schmidt trigger inverter. The problem I having is that I can not get
    enough of a pulse to trigger it using a simple coil.. Any ideas as to gauge and
    number of turns? etc?
    Thanks,
    J
    Leroy Hall <leroy@f...> wrote: please see:

    http://www.pcbcafe.com/BOOKS/SpiceHandBook/09_chapter08-08.php

    Leroy Hall wrote:
    >
    > The pickup is a small coil of wire wrapped around the spark plug lead,
    > with one of it's ends tied to ground on the engine. When the plug
    > fires, it generates a small pulse of current, which must be amplified &
    > conditioned before being sent to the stamp. Pulsein might then be used
    > to obtain engine rpm. An amplifier might be as simple as a 4049 CMOS
    > inverter chip, or maybe a CMOS schmidt trigger, can't remember the
    > number of that.
    >
    > HTH,
    >
    > Leroy
    >
    > Jim Gorbet wrote:
    > >
    > > I to am in interested in this. There is a company that sells them for racing
    karts http://www.digatron.cc but they are very expensive. I know that that they
    are using a pickup lead that clips to the sparkplug wire, but I have no idea how
    this works. I think that once you determine how to pick up a signal the rest
    would be easy. Or you could always use a hall effect sensor. Jameco sells a nice
    inexpensive one. Sorry couldnt help more.
    > > Thanks,
    > > Jim Gorbet
    > > jay_mann2000 Hello,
    > >
    > > I am wondering if anyone has implemented a rpm sensor for a small
    > > gasoline engine using a stamp? I am in search of a pulse for every
    > > spark of the engine (which occurs every revolution) The engine uses
    > > a standard magneto ignition. All help is greatly appreciated. I
    > > haven't had any luck designing my own [noparse]:([/noparse].
    > >
    > > Thanks,
    > > J
    > >
    > > To UNSUBSCRIBE, just send mail to:
    > > basicstamps-unsubscribe@yahoogroups.com
    > > from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.
    > >
    > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    > >
    > >
    > > Do You Yahoo!?
    > > Yahoo! Tax Center - online filing with TurboTax
    > >
    > > [noparse][[/noparse]Non-text portions of this message have been removed]
    > >
    > > To UNSUBSCRIBE, just send mail to:
    > > basicstamps-unsubscribe@yahoogroups.com
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  • ArchiverArchiver Posts: 46,084
    edited 2002-04-16 01:08
    Found something on the WEB last week. Use a clamp-on pickup(from a timing
    light)
    or 40 turns #22 on a Toroid. Connect across the LED of a Schmidt(Darlington?)
    Opto-coupler. Apparently the pulse generated is enough to light the LED( and
    generate a pluse on the output side).

    > Hello,
    >
    > I am wondering if anyone has implemented a rpm sensor for a small
    > gasoline engine using a stamp? I am in search of a pulse for every
    > spark of the engine (which occurs every revolution) The engine uses a
    > standard magneto ignition. All help is greatly appreciated. I haven't
    > had any luck designing my own [noparse]:([/noparse].
    >
  • ArchiverArchiver Posts: 46,084
    edited 2002-04-16 14:25
    very nice

    richard


    Original Message
    From: "Mike DeMetz" <miked@e...>
    To: <basicstamps@yahoogroups.com>
    Sent: Monday, April 15, 2002 7:08 PM
    Subject: [noparse][[/noparse]basicstamps] Re: Sensing RPM on a small gas engine
    (Briggs&Stratton 8hp)


    >
    > Found something on the WEB last week. Use a clamp-on pickup(from a timing
    > light)
    > or 40 turns #22 on a Toroid. Connect across the LED of a
    Schmidt(Darlington?)
    > Opto-coupler. Apparently the pulse generated is enough to light the LED(
    and
    > generate a pluse on the output side).
    >
    > > Hello,
    > >
    > > I am wondering if anyone has implemented a rpm sensor for a small
    > > gasoline engine using a stamp? I am in search of a pulse for every
    > > spark of the engine (which occurs every revolution) The engine uses a
    > > standard magneto ignition. All help is greatly appreciated. I haven't
    > > had any luck designing my own [noparse]:([/noparse].
    > >
    >
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
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