Shop OBEX P1 Docs P2 Docs Learn Events
Thanks to Chris and Ken, for my piezo — Parallax Forums

Thanks to Chris and Ken, for my piezo

ArchiverArchiver Posts: 46,084
edited 2003-03-27 15:16 in General Discussion
Wright on Chris, it was a piezo buzzer, i found a piezo speaker an
everything works fine, thanks alot i appreciate the help, in my days
we didnt have any piezo, so i'm kind new to this also, but now my
robot JORO2 his happy and chirping away...hihi.. also thanks to Ken
for his patience
John

--- In basicstamps@yahoogroups.com, Chris Savage
<knight_designs@y...> wrote:
> Sounds to me more like the device is a Piezo buzzer,
> which has it's own circuitry inside, if running it
> directly off 5V gives a tone. If that's the case,
> pulsing it with the stamp may not work.
>
> --- smartdim@a... wrote:
> > In a message dated 3/24/2003 10:59:23 AM Pacific
> > Standard Time,
> > johneck790@s... writes:
> >
> > > Hi Ken,
> > >
> > > i'm connecting the piezo across +4.8v (4x1.2v
> > nimh) and ground
> > > and the current is 5 ma
> > >
> > > thanks
> > >
> >
> > hmmmmmmmmm,
> >
> > If indeed the unit is pulling only 5ma, the stamp
> > should be able to directly
> > drive the buzzer.
> >
> > And, the NPN transistor idea should do the same. If
> > I remember correctly,
> > you stated you could pulse an LED?
> >
> > When you pulsed the LED, was the stamp providing
> > ground for the buzzer, or
> > power.
> >
> > If you pulsed the LED using ground, you should be
> > able to do the same to the
> > buzzer. And IF YOU ARE SURE the buzzer uses only
> > 5ma, no resistor is needed.
> > But to be safe, I recommend the transistor
> > idea....Again
> >
> > 2n2222 or 2n3904
> >
> > emitter to ground, base to the stamp pin through 1k
> > ohms and the collector to
> > one side of your buzzer and the other side of the
> > buzzer to your + 4.8 volts.
> >
> > Is the 4.8 volt source using the same ground as the
> > stamp power supply? The
> > ground for your buzzer must be tied to the same
> > ground as your stamp.
> >
> > Don't hesistate to write back if more help is
> > needed.
> > Ken
> >
> >
> > [noparse][[/noparse]Non-text portions of this message have been
> > removed]
> >
> >
> > 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/
> >
> >
>
>
> =====
> Chris Savage
> Knight Designs
> 324 West Main Street
> Montour Falls, NY 14865
> (607) 535-6777
>
> http://www.knightdesigns.com
>
> __________________________________________________
> Do you Yahoo!?
> Yahoo! Platinum - Watch CBS' NCAA March Madness, live on your
desktop!
> http://platinum.yahoo.com

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-03-25 15:09
    Something I might point out if you need more volume from your
    "piezo speaker". If you normally tie one leg of the piezo to
    ground, and the other to an I/O pin. If you use a simple
    inverter (74C14) and connect the piezo across the input and
    output of the inverter you effectively double the voltage that
    the piezo sees to 10V from only a 5V source!

    |\
    I/O>
    o----| \o----> to piezo
    | |/
    |
    o
    > to piezo

    -Beau Schwabe

    >Wright on Chris, it was a piezo buzzer, i found a piezo speaker an
    >everything works fine, thanks alot i appreciate the help, in my days
    >we didnt have any piezo, so i'm kind new to this also, but now my
    >robot JORO2 his happy and chirping away...hihi.. also thanks to Ken
    >for his patience
    >John
    >
    >--- In basicstamps@yahoogroups.com, Chris Savage
    ><knight_designs@y...> wrote:
    > > Sounds to me more like the device is a Piezo buzzer,
    > > which has it's own circuitry inside, if running it
    > > directly off 5V gives a tone. If that's the case,
    > > pulsing it with the stamp may not work.
    > >
    > > --- smartdim@a... wrote:
    > > > In a message dated 3/24/2003 10:59:23 AM Pacific
    > > > Standard Time,
    > > > johneck790@s... writes:
    > > >
    > > > > Hi Ken,
    > > > >
    > > > > i'm connecting the piezo across +4.8v (4x1.2v
    > > > nimh) and ground
    > > > > and the current is 5 ma
    > > > >
    > > > > thanks
    > > > >
    > > >
    > > > hmmmmmmmmm,
    > > >
    > > > If indeed the unit is pulling only 5ma, the stamp
    > > > should be able to directly
    > > > drive the buzzer.
    > > >
    > > > And, the NPN transistor idea should do the same. If
    > > > I remember correctly,
    > > > you stated you could pulse an LED?
    > > >
    > > > When you pulsed the LED, was the stamp providing
    > > > ground for the buzzer, or
    > > > power.
    > > >
    > > > If you pulsed the LED using ground, you should be
    > > > able to do the same to the
    > > > buzzer. And IF YOU ARE SURE the buzzer uses only
    > > > 5ma, no resistor is needed.
    > > > But to be safe, I recommend the transistor
    > > > idea....Again
    > > >
    > > > 2n2222 or 2n3904
    > > >
    > > > emitter to ground, base to the stamp pin through 1k
    > > > ohms and the collector to
    > > > one side of your buzzer and the other side of the
    > > > buzzer to your + 4.8 volts.
    > > >
    > > > Is the 4.8 volt source using the same ground as the
    > > > stamp power supply? The
    > > > ground for your buzzer must be tied to the same
    > > > ground as your stamp.
    > > >
    > > > Don't hesistate to write back if more help is
    > > > needed.
    > > > Ken
    > > >
  • ArchiverArchiver Posts: 46,084
    edited 2003-03-25 22:27
    --- johneck26 <johneck790@s...> wrote:
    > Wright on Chris, it was a piezo buzzer, i found a
    > piezo speaker an
    > everything works fine, thanks alot i appreciate the
    > help, in my days
    > we didnt have any piezo, so i'm kind new to this
    > also, but now my
    > robot JORO2 his happy and chirping away...hihi..
    > also thanks to Ken
    > for his patience
    > John

    No problem...In the past in pilfering Piezos from old
    boards, it can be hard to tell if certain devices are
    buzzers, or speakers (Piezo) when cased in the same
    black housing, which I have both kinds here.

    To differentiate, I simply apply 5-10VDC (Momentarily)
    to one in the correct polarity (Both devices seem
    polarized) and if it beeps, it's a buzzer...If not, I
    assume it's the piezo speaker. That's my old logic
    anyway...I rarely use the devices anymore except the
    ones that come in computer cases in place of the
    speaker. Anyway, take care!



    =====
    Chris Savage
    Knight Designs
    324 West Main Street
    Montour Falls, NY 14865
    (607) 535-6777

    http://www.knightdesigns.com

    __________________________________________________
    Do you Yahoo!?
    Yahoo! Platinum - Watch CBS' NCAA March Madness, live on your desktop!
    http://platinum.yahoo.com
  • ArchiverArchiver Posts: 46,084
    edited 2003-03-26 02:04
    Beau:

    Am I missing something? If you are using a 5V rail-to-rail supply, then
    connecting it from either rail to an output pin should result in the applied
    voltage being rail- to rail-, with the minuses being the amount of voltage
    dropped internally when the pin is switched, or floated (on the other leg)
    due to loading. So if you use an inverter, doesn't that still just give you
    rail- to rail-, with pretty much the same rail to rail (minus those losses
    above) applied voltage?

    Mic
    Original Message
    From: Beau Schwabe <bschwabe@a...>
    To: <basicstamps@yahoogroups.com>
    Sent: Tuesday, March 25, 2003 10:09 AM
    Subject: Re: [noparse][[/noparse]basicstamps] Thanks to Chris and Ken, for my piezo


    > Something I might point out if you need more volume from your
    > "piezo speaker". If you normally tie one leg of the piezo to
    > ground, and the other to an I/O pin. If you use a simple
    > inverter (74C14) and connect the piezo across the input and
    > output of the inverter you effectively double the voltage that
    > the piezo sees to 10V from only a 5V source!
    >
    > |\
    > I/O>
    o----| \o----> to piezo
    > | |/
    > |
    > o
    > to piezo
    >
    > -Beau Schwabe
    >
    > >Wright on Chris, it was a piezo buzzer, i found a piezo speaker an
    > >everything works fine, thanks alot i appreciate the help, in my days
    > >we didnt have any piezo, so i'm kind new to this also, but now my
    > >robot JORO2 his happy and chirping away...hihi.. also thanks to Ken
    > >for his patience
    > >John
    > >
    > >--- In basicstamps@yahoogroups.com, Chris Savage
    > ><knight_designs@y...> wrote:
    > > > Sounds to me more like the device is a Piezo buzzer,
    > > > which has it's own circuitry inside, if running it
    > > > directly off 5V gives a tone. If that's the case,
    > > > pulsing it with the stamp may not work.
    > > >
    > > > --- smartdim@a... wrote:
    > > > > In a message dated 3/24/2003 10:59:23 AM Pacific
    > > > > Standard Time,
    > > > > johneck790@s... writes:
    > > > >
    > > > > > Hi Ken,
    > > > > >
    > > > > > i'm connecting the piezo across +4.8v (4x1.2v
    > > > > nimh) and ground
    > > > > > and the current is 5 ma
    > > > > >
    > > > > > thanks
    > > > > >
    > > > >
    > > > > hmmmmmmmmm,
    > > > >
    > > > > If indeed the unit is pulling only 5ma, the stamp
    > > > > should be able to directly
    > > > > drive the buzzer.
    > > > >
    > > > > And, the NPN transistor idea should do the same. If
    > > > > I remember correctly,
    > > > > you stated you could pulse an LED?
    > > > >
    > > > > When you pulsed the LED, was the stamp providing
    > > > > ground for the buzzer, or
    > > > > power.
    > > > >
    > > > > If you pulsed the LED using ground, you should be
    > > > > able to do the same to the
    > > > > buzzer. And IF YOU ARE SURE the buzzer uses only
    > > > > 5ma, no resistor is needed.
    > > > > But to be safe, I recommend the transistor
    > > > > idea....Again
    > > > >
    > > > > 2n2222 or 2n3904
    > > > >
    > > > > emitter to ground, base to the stamp pin through 1k
    > > > > ohms and the collector to
    > > > > one side of your buzzer and the other side of the
    > > > > buzzer to your + 4.8 volts.
    > > > >
    > > > > Is the 4.8 volt source using the same ground as the
    > > > > stamp power supply? The
    > > > > ground for your buzzer must be tied to the same
    > > > > ground as your stamp.
    > > > >
    > > > > Don't hesistate to write back if more help is
    > > > > needed.
    > > > > Ken
    > > > >
    >
    >
    >
    > 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 2003-03-26 02:21
    In a message dated 3/25/2003 6:11:57 PM Pacific Standard Time,
    michael_duerksen@c... writes:

    > Beau:
    >
    > Am I missing something? If you are using a 5V rail-to-rail supply, then
    > connecting it from either rail to an output pin should result in the
    > applied
    > voltage being rail- to rail-, with the minuses being the amount of voltage
    > dropped internally when the pin is switched, or floated (on the other leg)
    > due to loading. So if you use an inverter, doesn't that still just give you
    > rail- to rail-, with pretty much the same rail to rail (minus those losses
    > above) applied voltage?
    >
    > Mic
    >

    Mic & Beau,

    I was wondering the same......


    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2003-03-26 16:10
    At 09:21 PM 3/25/03 -0500, you wrote:
    >In a message dated 3/25/2003 6:11:57 PM Pacific Standard Time,
    >michael_duerksen@c... writes:
    >
    > > Beau:
    > >
    > > Am I missing something? If you are using a 5V rail-to-rail supply, then
    > > connecting it from either rail to an output pin should result in the
    > > applied
    > > voltage being rail- to rail-, with the minuses being the amount of voltage
    > > dropped internally when the pin is switched, or floated (on the other leg)
    > > due to loading. So if you use an inverter, doesn't that still just give you
    > > rail- to rail-, with pretty much the same rail to rail (minus those losses
    > > above) applied voltage?
    > >
    > > Mic
    > >
    >
    >Mic & Beau,
    >
    >I was wondering the same......

    Consider a piezo like a capacitor... charge it by applying power...

    +5V>
    |peizo|
    <GND
    + 5V -

    ...Now reverse polarity...

    GND>
    |peizo|
    <+5V
    + 5V -

    ...for a brief moment the piezo will
    see 10V before it reverses polarity itself.


    -Beau Schwabe
  • ArchiverArchiver Posts: 46,084
    edited 2003-03-27 03:04
    Thanks. Interesting thought. I never even heard of a piezo used that way.
    So, essentially, because of the switching process, which I didn't fully
    understand then or now, so I'll take your word for that part, you will get a
    LOUD but relatively short pulsed tone?

    Mike
    Original Message
    From: Beau Schwabe <bschwabe@a...>
    To: <basicstamps@yahoogroups.com>
    Sent: Wednesday, March 26, 2003 11:10 AM
    Subject: Re: [noparse][[/noparse]basicstamps] Thanks to Chris and Ken, for my piezo


    > At 09:21 PM 3/25/03 -0500, you wrote:
    > >In a message dated 3/25/2003 6:11:57 PM Pacific Standard Time,
    > >michael_duerksen@c... writes:
    > >
    > > > Beau:
    > > >
    > > > Am I missing something? If you are using a 5V rail-to-rail supply,
    then
    > > > connecting it from either rail to an output pin should result in the
    > > > applied
    > > > voltage being rail- to rail-, with the minuses being the amount of
    voltage
    > > > dropped internally when the pin is switched, or floated (on the other
    leg)
    > > > due to loading. So if you use an inverter, doesn't that still just
    give you
    > > > rail- to rail-, with pretty much the same rail to rail (minus those
    losses
    > > > above) applied voltage?
    > > >
    > > > Mic
    > > >
    > >
    > >Mic & Beau,
    > >
    > >I was wondering the same......
    >
    > Consider a piezo like a capacitor... charge it by applying power...
    >
    > +5V>
    |peizo|
    <GND
    > + 5V -
    >
    > ...Now reverse polarity...
    >
    > GND>
    |peizo|
    <+5V
    > + 5V -
    >
    > ...for a brief moment the piezo will
    > see 10V before it reverses polarity itself.
    >
    >
    > -Beau Schwabe
    >
    >
    >
    >
    > 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 2003-03-27 15:16
    Not exactly, The piezo will be louder, but the tone is determined by your
    switching speed.

    Folks, a piezo is a crystal, but it has properties similar to a capacitor.

    Try this:
    +9VBattery terminal>
    piezo
    momentary switch----<-9VBattery terminal

    Initially when you press the button, the piezo will produce a louder pop, than
    successive attempts at pressing the button, because the crystal in the piezo is
    "charged" and deflects. Now, if you short the leads of the piezo without
    applying
    any power, you will hear another loud pop because now the crystal has become
    "discharged" and relaxed. This mechanical motion results in the production of
    sound.

    Equiv circuit:
    (charge)
    +9VBattery terminal>
    piezo
    <-9VBattery terminal

    (discharge)
    -9VBattery terminal>
    piezo
    <-9VBattery terminal

    ...with one terminal tied to ground the above circuit is essentially what
    you are
    doing when you toggle a pin HIGH or LOW.

    Now think about this, instead of shorting the leads of the piezo as mentioned
    above, simply reverse the polarity. This causes the piezo to "charge" in the
    opposite direction thus causing the crystal to deflect in the opposite
    direction.
    With roughly twice the mechanical displacement, the result is a louder sound.

    Equiv circuit: (notice no discharge!)
    (charge)
    +9VBattery terminal>
    piezo
    <-9VBattery terminal

    (charge)
    -9VBattery terminal>
    piezo
    <+9VBattery terminal


    -Beau Schwabe


    >Thanks. Interesting thought. I never even heard of a piezo used that way.
    >So, essentially, because of the switching process, which I didn't fully
    >understand then or now, so I'll take your word for that part, you will get a
    >LOUD but relatively short pulsed tone?
    >
    >Mike
    >
    Original Message
    >From: Beau Schwabe <bschwabe@a...>
    >To: <basicstamps@yahoogroups.com>
    >Sent: Wednesday, March 26, 2003 11:10 AM
    >Subject: Re: [noparse][[/noparse]basicstamps] Thanks to Chris and Ken, for my piezo
    >
    >
    > > At 09:21 PM 3/25/03 -0500, you wrote:
    > > >In a message dated 3/25/2003 6:11:57 PM Pacific Standard Time,
    > > >michael_duerksen@c... writes:
    > > >
    > > > > Beau:
    > > > >
    > > > > Am I missing something? If you are using a 5V rail-to-rail supply,
    >then
    > > > > connecting it from either rail to an output pin should result in the
    > > > > applied
    > > > > voltage being rail- to rail-, with the minuses being the amount of
    >voltage
    > > > > dropped internally when the pin is switched, or floated (on the other
    >leg)
    > > > > due to loading. So if you use an inverter, doesn't that still just
    >give you
    > > > > rail- to rail-, with pretty much the same rail to rail (minus those
    >losses
    > > > > above) applied voltage?
    > > > >
    > > > > Mic
    > > > >
    > > >
    > > >Mic & Beau,
    > > >
    > > >I was wondering the same......
    > >
    > > Consider a piezo like a capacitor... charge it by applying power...
    > >
    > > +5V>
    |peizo|
    <GND
    > > + 5V -
    > >
    > > ...Now reverse polarity...
    > >
    > > GND>
    |peizo|
    <+5V
    > > + 5V -
    > >
    > > ...for a brief moment the piezo will
    > > see 10V before it reverses polarity itself.
    > >
    > >
    > > -Beau Schwabe
    > >
Sign In or Register to comment.