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Alternating Signal Direction?? — Parallax Forums

Alternating Signal Direction??

ArchiverArchiver Posts: 46,084
edited 2002-07-07 17:22 in General Discussion
Hello All,

I have a slightly off topic question. My project is Basic Stamp
controlled, but my question is regarding a small side circuit that I hope
you can help with. I have 5 volt pulses coming from an optical sensor that
trigger a transistor acting as a switch - simple enough. I would like to
have the pulse train trigger two transistors, one at a time, alternating
from one to the other. One pulse triggers the first transistor, the next
pulse triggers the second, the next triggers the first again - and so on.
What methods would you guys recommend to create this alternating effect to
direct signal pulses from one transistor to the other?

Many thanks for any and all input,

Tim

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2002-07-07 03:29
    I would suggest a flip flop integrated circuit, easier than doing it with
    transistors.
    Unless your driving something that needs more than 20ma or so, you could
    forego the
    transistors.

    Original Message
    From: Tim and Jo [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=h032uquIe_z8ySGkUQZp_PVs1U1tuggpvOlh6u_VVlmy7KBEOQPaS_d76mXRSE29KcFz]dema@t...[/url
    Sent: Saturday, July 06, 2002 8:48 PM
    To: Basic Stamp List
    Subject: [noparse][[/noparse]basicstamps] Alternating Signal Direction??


    Hello All,

    I have a slightly off topic question. My project is Basic Stamp
    controlled, but my question is regarding a small side circuit that I hope
    you can help with. I have 5 volt pulses coming from an optical sensor that
    trigger a transistor acting as a switch - simple enough. I would like to
    have the pulse train trigger two transistors, one at a time, alternating
    from one to the other. One pulse triggers the first transistor, the next
    pulse triggers the second, the next triggers the first again - and so on.
    What methods would you guys recommend to create this alternating effect to
    direct signal pulses from one transistor to the other?

    Many thanks for any and all input,

    Tim




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  • ArchiverArchiver Posts: 46,084
    edited 2002-07-07 04:14
    Thanks Earl,

    Is that the basic purpose of a flip-flop? Can you recommend any part
    numbers?

    Tim
    Original Message
    From: "Earl Bollinger" <earlwbollinger@a...>
    To: <basicstamps@yahoogroups.com>
    Sent: Saturday, July 06, 2002 7:29 PM
    Subject: RE: [noparse][[/noparse]basicstamps] Alternating Signal Direction??


    > I would suggest a flip flop integrated circuit, easier than doing it with
    > transistors.
    > Unless your driving something that needs more than 20ma or so, you could
    > forego the
    > transistors.
    >
    >
    Original Message
    > From: Tim and Jo [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=HHvEZK_o3OXKpoySVFf6-iHp3IGyt7mfGqYp_rFK6Bsc2jsWv5eDMez2M8ZKz40NnVg]dema@t...[/url
    > Sent: Saturday, July 06, 2002 8:48 PM
    > To: Basic Stamp List
    > Subject: [noparse][[/noparse]basicstamps] Alternating Signal Direction??
    >
    >
    > Hello All,
    >
    > I have a slightly off topic question. My project is Basic Stamp
    > controlled, but my question is regarding a small side circuit that I hope
    > you can help with. I have 5 volt pulses coming from an optical sensor
    that
    > trigger a transistor acting as a switch - simple enough. I would like to
    > have the pulse train trigger two transistors, one at a time, alternating
    > from one to the other. One pulse triggers the first transistor, the next
    > pulse triggers the second, the next triggers the first again - and so on.
    > What methods would you guys recommend to create this alternating effect to
    > direct signal pulses from one transistor to the other?
    >
    > Many thanks for any and all input,
    >
    > Tim
    >
    >
    >
    >
    > 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/
    >
    >
    >
    >
    >
    > 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/
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2002-07-07 12:42
    The flipflops originally were used for memory storage many years ago. You
    could store a 1 or a 0 in it and read that value as many times as needed.
    Another old use was as a frequency divider (divide by two).

    The standard flip flop would be a SN7474 dual flipflop
    It now comes in a number varieties such as 74L74, 74LS74, 74HC74 and so on.
    But for your purposes they are all the same.
    http://www.fairchildsemi.com/ds/74/74ACT74.pdf
    Here in the US, you can get them at Radio Shack fairly easily. But
    www.jameco.com, www.allelectronics.com,
    www.bgmicro.com, www.digikey.com should have some variety of the flipflop.

    Another flip flop type is the CMOS version CD4013 which has a wider voltage
    range over the regular TTL versions
    http://rocky.digikey.com/WebLib/Texas%20Instruments/Web%20data/CD4013B.pdf
    Radio shack sells these too (or it may be one or the other I forget right
    now).

    The basic operation would be that you run your signal into clock/pulse
    input. Everytime you get a pulse or clock it will toggle the flipflop,
    splitting your signal like you wanted. You can use clear input to reset the
    flipflop back to a known state.

    Original Message
    From: Tim and Jo [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=4zTvECtiN75xo0G-Awfq6G0caZO3V4hG3v8-KChK9ehAZYu-Dl9IADhptc9mrAFnN7Cm]dema@t...[/url
    Sent: Saturday, July 06, 2002 10:15 PM
    To: basicstamps@yahoogroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] Alternating Signal Direction??


    Thanks Earl,

    Is that the basic purpose of a flip-flop? Can you recommend any part
    numbers?

    Tim
    Original Message
    From: "Earl Bollinger" <earlwbollinger@a...>
    To: <basicstamps@yahoogroups.com>
    Sent: Saturday, July 06, 2002 7:29 PM
    Subject: RE: [noparse][[/noparse]basicstamps] Alternating Signal Direction??


    > I would suggest a flip flop integrated circuit, easier than doing it with
    > transistors.
    > Unless your driving something that needs more than 20ma or so, you could
    > forego the
    > transistors.
    >
    >
    Original Message
    > From: Tim and Jo [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=4zTvECtiN75xo0G-Awfq6G0caZO3V4hG3v8-KChK9ehAZYu-Dl9IADhptc9mrAFnN7Cm]dema@t...[/url
    > Sent: Saturday, July 06, 2002 8:48 PM
    > To: Basic Stamp List
    > Subject: [noparse][[/noparse]basicstamps] Alternating Signal Direction??
    >
    >
    > Hello All,
    >
    > I have a slightly off topic question. My project is Basic Stamp
    > controlled, but my question is regarding a small side circuit that I hope
    > you can help with. I have 5 volt pulses coming from an optical sensor
    that
    > trigger a transistor acting as a switch - simple enough. I would like to
    > have the pulse train trigger two transistors, one at a time, alternating
    > from one to the other. One pulse triggers the first transistor, the next
    > pulse triggers the second, the next triggers the first again - and so on.
    > What methods would you guys recommend to create this alternating effect to
    > direct signal pulses from one transistor to the other?
    >
    > Many thanks for any and all input,
    >
    > Tim
    >
    >
    >
    >
    > 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/
    >
    >
    >
    >
    >
    > 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/
    >
    >



    To UNSUBSCRIBE, just send mail to:
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  • ArchiverArchiver Posts: 46,084
    edited 2002-07-07 17:22
    Thanks for all the info and links Earl - that helps very much! Looks like
    just the solution I'd hoped for.

    Tim

    Original Message
    From: "Earl Bollinger" <earlwbollinger@a...>
    To: <basicstamps@yahoogroups.com>
    Sent: Sunday, July 07, 2002 4:42 AM
    Subject: RE: [noparse][[/noparse]basicstamps] Alternating Signal Direction??


    > The flipflops originally were used for memory storage many years ago. You
    > could store a 1 or a 0 in it and read that value as many times as needed.
    > Another old use was as a frequency divider (divide by two).
    >
    > The standard flip flop would be a SN7474 dual flipflop
    > It now comes in a number varieties such as 74L74, 74LS74, 74HC74 and so
    on.
    > But for your purposes they are all the same.
    > http://www.fairchildsemi.com/ds/74/74ACT74.pdf
    > Here in the US, you can get them at Radio Shack fairly easily. But
    > www.jameco.com, www.allelectronics.com,
    > www.bgmicro.com, www.digikey.com should have some variety of the flipflop.
    >
    > Another flip flop type is the CMOS version CD4013 which has a wider
    voltage
    > range over the regular TTL versions
    > http://rocky.digikey.com/WebLib/Texas%20Instruments/Web%20data/CD4013B.pdf
    > Radio shack sells these too (or it may be one or the other I forget right
    > now).
    >
    > The basic operation would be that you run your signal into clock/pulse
    > input. Everytime you get a pulse or clock it will toggle the flipflop,
    > splitting your signal like you wanted. You can use clear input to reset
    the
    > flipflop back to a known state.
    >
    >
    Original Message
    > From: Tim and Jo [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=VJ_SY59dlTyuQjbmiwbLsY47eOw99o4XI6zWSjJuQKCB8itish9FG2wlv4cGsGv1WGDS]dema@t...[/url
    > Sent: Saturday, July 06, 2002 10:15 PM
    > To: basicstamps@yahoogroups.com
    > Subject: Re: [noparse][[/noparse]basicstamps] Alternating Signal Direction??
    >
    >
    > Thanks Earl,
    >
    > Is that the basic purpose of a flip-flop? Can you recommend any part
    > numbers?
    >
    > Tim
    >
    Original Message
    > From: "Earl Bollinger" <earlwbollinger@a...>
    > To: <basicstamps@yahoogroups.com>
    > Sent: Saturday, July 06, 2002 7:29 PM
    > Subject: RE: [noparse][[/noparse]basicstamps] Alternating Signal Direction??
    >
    >
    > > I would suggest a flip flop integrated circuit, easier than doing it
    with
    > > transistors.
    > > Unless your driving something that needs more than 20ma or so, you could
    > > forego the
    > > transistors.
    > >
    > >
    Original Message
    > > From: Tim and Jo [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=VJ_SY59dlTyuQjbmiwbLsY47eOw99o4XI6zWSjJuQKCB8itish9FG2wlv4cGsGv1WGDS]dema@t...[/url
    > > Sent: Saturday, July 06, 2002 8:48 PM
    > > To: Basic Stamp List
    > > Subject: [noparse][[/noparse]basicstamps] Alternating Signal Direction??
    > >
    > >
    > > Hello All,
    > >
    > > I have a slightly off topic question. My project is Basic Stamp
    > > controlled, but my question is regarding a small side circuit that I
    hope
    > > you can help with. I have 5 volt pulses coming from an optical sensor
    > that
    > > trigger a transistor acting as a switch - simple enough. I would like
    to
    > > have the pulse train trigger two transistors, one at a time, alternating
    > > from one to the other. One pulse triggers the first transistor, the
    next
    > > pulse triggers the second, the next triggers the first again - and so
    on.
    > > What methods would you guys recommend to create this alternating effect
    to
    > > direct signal pulses from one transistor to the other?
    > >
    > > Many thanks for any and all input,
    > >
    > > Tim
    > >
    > >
    > >
    > >
    > > 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/
    > >
    > >
    > >
    > >
    > >
    > > 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/
    > >
    > >
    >
    >
    >
    > 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.
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    >
    >
    >
    >
    >
    > 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.
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    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
    >
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