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Single Seat Off Road Race Car - HELP — Parallax Forums

Single Seat Off Road Race Car - HELP

ArchiverArchiver Posts: 46,084
edited 2002-03-13 15:58 in General Discussion
>I am working on a dashboard system for a single-seat off road race
>car used in the SAE Mini Baja Competition( I am a Electromechanical
>Engineering Student at Wentworth in Boston) We are looking to sense
>engine rpm and I need a way to output a digital pulse for
>every 'spark' of the ignition (the spark happens on every revolution
>even though the power stroke is every other) anyways.. I know there
>are tachs out there that simply wrap around the spark plug wire. If
>there is anyone who knows how to do this it would be greatly
>appreciated.
>
>Additionally, The fuel level is being sensed using a float that
>changes resistance proportionalto the height of the fuel (230-30 ohms
>over full to empty range). What is the easiest way to condition this
>signal to 0-5v without the luxury of dual supplies. (We are running
>on 12v battery for power). I know how to do it using a differential
>amplifier but that requires the use of a negative supply (I think).
>
>Any help will be greatly appreciated as we are working on this as we
>speak.

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2002-03-11 17:35
    jay, here is a small jpg of a schematic to get the pulses from a spark plug
    wire, or coil wire if you need to count all the firings.

    normdoty@h...



    >From: "jay_mann2000" <jay_mann2000@y...>
    >Reply-To: basicstamps@yahoogroups.com
    >To: basicstamps@yahoogroups.com
    >Subject: [noparse][[/noparse]basicstamps] Single Seat Off Road Race Car - HELP
    >Date: Mon, 11 Mar 2002 16:25:38 -0000
    >
    > >I am working on a dashboard system for a single-seat off road race
    > >car used in the SAE Mini Baja Competition( I am a Electromechanical
    > >Engineering Student at Wentworth in Boston) We are looking to sense
    > >engine rpm and I need a way to output a digital pulse for
    > >every 'spark' of the ignition (the spark happens on every revolution
    > >even though the power stroke is every other) anyways.. I know there
    > >are tachs out there that simply wrap around the spark plug wire. If
    > >there is anyone who knows how to do this it would be greatly
    > >appreciated.
    > >
    > >Additionally, The fuel level is being sensed using a float that
    > >changes resistance proportionalto the height of the fuel (230-30 ohms
    > >over full to empty range). What is the easiest way to condition this
    > >signal to 0-5v without the luxury of dual supplies. (We are running
    > >on 12v battery for power). I know how to do it using a differential
    > >amplifier but that requires the use of a negative supply (I think).
    > >
    > >Any help will be greatly appreciated as we are working on this as we
    > >speak.
    >
    >
    >
    >To UNSUBSCRIBE, just send mail to:
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    >
    >




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  • ArchiverArchiver Posts: 46,084
    edited 2002-03-11 17:50
    That would be of interest to me also but I think the list filters
    attachments. Could you email it to me directly or give me a URL where I can
    find it.
    Thanks


    At 05:35 PM 3/11/02 +0000, norman doty wrote:
    >jay, here is a small jpg of a schematic to get the pulses from a spark plug
    >wire, or coil wire if you need to count all the firings.
    >
    >normdoty@h...
    >
    >
    >
    > >From: "jay_mann2000" <jay_mann2000@y...>
    > >Reply-To: basicstamps@yahoogroups.com
    > >To: basicstamps@yahoogroups.com
    > >Subject: [noparse][[/noparse]basicstamps] Single Seat Off Road Race Car - HELP
    > >Date: Mon, 11 Mar 2002 16:25:38 -0000
    > >
    > > >I am working on a dashboard system for a single-seat off road race
    > > >car used in the SAE Mini Baja Competition( I am a Electromechanical
    > > >Engineering Student at Wentworth in Boston) We are looking to sense
    > > >engine rpm and I need a way to output a digital pulse for
    > > >every 'spark' of the ignition (the spark happens on every revolution
    > > >even though the power stroke is every other) anyways.. I know there
    > > >are tachs out there that simply wrap around the spark plug wire. If
    > > >there is anyone who knows how to do this it would be greatly
    > > >appreciated.
    > > >
    > > >Additionally, The fuel level is being sensed using a float that
    > > >changes resistance proportionalto the height of the fuel (230-30 ohms
    > > >over full to empty range). What is the easiest way to condition this
    > > >signal to 0-5v without the luxury of dual supplies. (We are running
    > > >on 12v battery for power). I know how to do it using a differential
    > > >amplifier but that requires the use of a negative supply (I think).
    > > >
    > > >Any help will be greatly appreciated as we are working on this as we
    > > >speak.
    > >
    > >
    > >
    > >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/
    > >
    > >
    >
    >
    >
    >
    >_________________________________________________________________
    >Join the world's largest e-mail service with MSN Hotmail.
    >http://www.hotmail.com
    >
    >
    >[noparse][[/noparse]Non-text portions of this message have been removed]
    >
    >
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    Larry G. Nelson Sr.
    mailto:L.Nelson@i...
    http://www.ultranet.com/~nr
  • ArchiverArchiver Posts: 46,084
    edited 2002-03-11 19:32
    Hi,
    I did a quick schematic using a LM358 op-amp, 7 resistors (all but one
    preferred values) and a zenner. Should give about 3% accuracy for the
    gauge.
    Which way does the sender go ?. I assumed 30 ohms full, 230 ohms empty.
    All will work from a single rail 12v dc supply. If this is of any use,
    e-mail me and I'll scan the circuit and e-mail it to you.

    Rob

    Original Message
    From: jay_mann2000 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=brvvARhaQvwiSmd4gLB73d9Eux3MlZrJeJgYxA2-xNl0JTYddMNUCqx9G9ryLKwiKphQM4re7BE4aY5yS4g]jay_mann2000@y...[/url
    Sent: 11 March 2002 16:26
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Single Seat Off Road Race Car - HELP

    >I am working on a dashboard system for a single-seat off road race
    >car used in the SAE Mini Baja Competition( I am a Electromechanical
    >Engineering Student at Wentworth in Boston) We are looking to sense
    >engine rpm and I need a way to output a digital pulse for
    >every 'spark' of the ignition (the spark happens on every revolution
    >even though the power stroke is every other) anyways.. I know there
    >are tachs out there that simply wrap around the spark plug wire. If
    >there is anyone who knows how to do this it would be greatly
    >appreciated.
    >
    >Additionally, The fuel level is being sensed using a float that
    >changes resistance proportionalto the height of the fuel (230-30 ohms
    >over full to empty range). What is the easiest way to condition this
    >signal to 0-5v without the luxury of dual supplies. (We are running
    >on 12v battery for power). I know how to do it using a differential
    >amplifier but that requires the use of a negative supply (I think).
    >
    >Any help will be greatly appreciated as we are working on this as we
    >speak.



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  • ArchiverArchiver Posts: 46,084
    edited 2002-03-12 02:17
    Yeah,
    That would be great! Thanks a lot.. if you want to you can just email me the
    scanned schematic directly.. It is 230 ohms Empty I believe...
    Thanks again,
    J
    Rob <robbed666@b...> wrote: Hi,
    I did a quick schematic using a LM358 op-amp, 7 resistors (all but one
    preferred values) and a zenner. Should give about 3% accuracy for the
    gauge.
    Which way does the sender go ?. I assumed 30 ohms full, 230 ohms empty.
    All will work from a single rail 12v dc supply. If this is of any use,
    e-mail me and I'll scan the circuit and e-mail it to you.

    Rob

    Original Message
    From: jay_mann2000 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=9fs1HocsCTP2wJ-pDA39OqajUYkDVor8L_eDUqFFlNeH25vMo9CKkj-nCCnudbhikn6F-dv-bk2hCfUn]jay_mann2000@y...[/url
    Sent: 11 March 2002 16:26
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Single Seat Off Road Race Car - HELP

    >I am working on a dashboard system for a single-seat off road race
    >car used in the SAE Mini Baja Competition( I am a Electromechanical
    >Engineering Student at Wentworth in Boston) We are looking to sense
    >engine rpm and I need a way to output a digital pulse for
    >every 'spark' of the ignition (the spark happens on every revolution
    >even though the power stroke is every other) anyways.. I know there
    >are tachs out there that simply wrap around the spark plug wire. If
    >there is anyone who knows how to do this it would be greatly
    >appreciated.
    >
    >Additionally, The fuel level is being sensed using a float that
    >changes resistance proportionalto the height of the fuel (230-30 ohms
    >over full to empty range). What is the easiest way to condition this
    >signal to 0-5v without the luxury of dual supplies. (We are running
    >on 12v battery for power). I know how to do it using a differential
    >amplifier but that requires the use of a negative supply (I think).
    >
    >Any help will be greatly appreciated as we are working on this as we
    >speak.



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  • ArchiverArchiver Posts: 46,084
    edited 2002-03-13 05:44
    Norm,

    Please email me that picture too!

    Darryl

    At 05:35 PM 11/03/02 +0000, you wrote:
    >jay, here is a small jpg of a schematic to get the pulses from a spark plug
    >wire, or coil wire if you need to count all the firings.
    >
    >normdoty@h...
    >
    >
    >
    > >From: "jay_mann2000" <jay_mann2000@y...>
    > >Reply-To: basicstamps@yahoogroups.com
    > >To: basicstamps@yahoogroups.com
    > >Subject: [noparse][[/noparse]basicstamps] Single Seat Off Road Race Car - HELP
    > >Date: Mon, 11 Mar 2002 16:25:38 -0000
    > >
    > > >I am working on a dashboard system for a single-seat off road race
    > > >car used in the SAE Mini Baja Competition( I am a Electromechanical
    > > >Engineering Student at Wentworth in Boston) We are looking to sense
    > > >engine rpm and I need a way to output a digital pulse for
    > > >every 'spark' of the ignition (the spark happens on every revolution
    > > >even though the power stroke is every other) anyways.. I know there
    > > >are tachs out there that simply wrap around the spark plug wire. If
    > > >there is anyone who knows how to do this it would be greatly
    > > >appreciated.
    > > >
    > > >Additionally, The fuel level is being sensed using a float that
    > > >changes resistance proportionalto the height of the fuel (230-30 ohms
    > > >over full to empty range). What is the easiest way to condition this
    > > >signal to 0-5v without the luxury of dual supplies. (We are running
    > > >on 12v battery for power). I know how to do it using a differential
    > > >amplifier but that requires the use of a negative supply (I think).
    > > >
    > > >Any help will be greatly appreciated as we are working on this as we
    > > >speak.
    > >
    > >
    > >
    > >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/
    > >
    > >
    >
    >
    >
    >
    >_________________________________________________________________
    >Join the world's largest e-mail service with MSN Hotmail.
    >http://www.hotmail.com
    >
    >
    >[noparse][[/noparse]Non-text portions of this message have been removed]
    >
    >
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  • ArchiverArchiver Posts: 46,084
    edited 2002-03-13 15:58
    message here, no problem.
    norm



    >From: Darryl Teichroeb <dteich@s...>
    >Reply-To: basicstamps@yahoogroups.com
    >To: basicstamps@yahoogroups.com
    >Subject: Re: [noparse][[/noparse]basicstamps] Single Seat Off Road Race Car - HELP
    >Date: Tue, 12 Mar 2002 22:44:09 -0700
    >
    >Norm,
    >
    >Please email me that picture too!
    >
    >Darryl
    >
    >At 05:35 PM 11/03/02 +0000, you wrote:
    > >jay, here is a small jpg of a schematic to get the pulses from a spark
    >plug
    > >wire, or coil wire if you need to count all the firings.
    > >
    > >normdoty@h...
    > >
    > >
    > >
    > > >From: "jay_mann2000" <jay_mann2000@y...>
    > > >Reply-To: basicstamps@yahoogroups.com
    > > >To: basicstamps@yahoogroups.com
    > > >Subject: [noparse][[/noparse]basicstamps] Single Seat Off Road Race Car - HELP
    > > >Date: Mon, 11 Mar 2002 16:25:38 -0000
    > > >
    > > > >I am working on a dashboard system for a single-seat off road race
    > > > >car used in the SAE Mini Baja Competition( I am a Electromechanical
    > > > >Engineering Student at Wentworth in Boston) We are looking to sense
    > > > >engine rpm and I need a way to output a digital pulse for
    > > > >every 'spark' of the ignition (the spark happens on every revolution
    > > > >even though the power stroke is every other) anyways.. I know there
    > > > >are tachs out there that simply wrap around the spark plug wire. If
    > > > >there is anyone who knows how to do this it would be greatly
    > > > >appreciated.
    > > > >
    > > > >Additionally, The fuel level is being sensed using a float that
    > > > >changes resistance proportionalto the height of the fuel (230-30 ohms
    > > > >over full to empty range). What is the easiest way to condition this
    > > > >signal to 0-5v without the luxury of dual supplies. (We are running
    > > > >on 12v battery for power). I know how to do it using a differential
    > > > >amplifier but that requires the use of a negative supply (I think).
    > > > >
    > > > >Any help will be greatly appreciated as we are working on this as we
    > > > >speak.
    > > >
    > > >
    > > >
    > > >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/
    > > >
    > > >
    > >
    > >
    > >
    > >
    > >_________________________________________________________________
    > >Join the world's largest e-mail service with MSN Hotmail.
    > >http://www.hotmail.com
    > >
    > >
    > >[noparse][[/noparse]Non-text portions of this message have been removed]
    > >
    > >
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