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Re: How to increase the volume of a metronome?

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rickman <gnuarm@gmail.com> wrote:
> On 2/24/2017 4:23 PM, tabbypurr@gmail.com wrote:
>> On Friday, 24 February 2017 20:46:36 UTC, rickman  wrote:
>>> On 2/24/2017 3:37 PM, tabbypurr wrote:
>>
>>>>> I get some  600+mA into the speaker which I would think is
>>>>> enough, but you'll have to test it to see.  This also solves the power
>>>>> consumption issue dropping the current over most of the cycle to what it
>>>>> takes to charge the timing cap.
>>>>>
>>>>> When I was working on radio design we were able to drive a 2 watt
>>>>> speaker using just 5 volts.  I can't imagine you won't get enough volume
>>>>> out of this.  If you don't, try increasing the value of C1.  That will
>>>>> give you a wider pulse.
>>>>>
>>>>> If Vol1 and Vol2 are supposed to be a volume potentiometer, you will
>>>>> find the pulse width changing as you change the volume.  Add a series
>>>>> resistor in line with C1 to give a consistent pulse width over the
>>>>> volume range and reduce the value of C1 to suit.  This may reduce the
>>>>> volume too much which means you will need a second transistor.  This is
>>>>> a bit more complex, so come back and I'll show you how to add that.
>>>>>
>>>>> As others have said, the 2N3904 is not rated for the currents, but they
>>>>> are only pulses, so it won't over heat the devices.  Still, a 1 amp part
>>>>> would be good.  No need for a heat sink.
>>>>
>>>>
>>>> A 5.2 ohm woofer on a 9v line: 1A transistor is not enough.
>>>
>>> A 9 volt line from a 9 volt battery with a 2 ohm output resistance.  A 1
>>> amp transistor will drive the speaker from his junk pile just fine.  I
>>> didn't see where he was going to connect this to a woofer.
>>
>> IIUC he dropped the idea of a battery and went with a wallwart. Either
>> way it has a 100uF cap on the psu rails. 5.2 ohm speaker
>> with or without 2ohm supply impedace still gets you over 1A.
>>
>> Woofer details are in loudspeaker.lib.
>
> Who changed it to a 5.2 ohm woofer?  That sounds like overkill to me.

Measured voice coil resistance (Re) is one of the parameters used in
loudspeaker.lib. My metronome uses a Realistic Minimus 0.3 Bookshelf
Speaker (shown here http://www.ebay.com/itm/272541834843 ). It gives the
beat a "warm" timbre.

That Realistic speaker displays a measured voice coil resistance of 6.5
ohms. It's closer to the Dayton Audio RS225-8 8" Reference Woofer in
loudspeaker.lib than the IB3858 speaker used in my metronome.asc.

Vol1 and Vol2 do indeed represent a pot. If anyone knows a better way to
do that in spice, please let me know.

On another note, the LM386 may obviate the need for a wall wart.
Regardless, the transistor ideas that you guys are kicking around pique
my interest and will be followed up on.

Learning something new every day. Carry on. :0)

Thank you,

--
Don Kuenz KB7RPU

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Thread

How to increase the volume of a metronome? Don Kuenz <g@crcomp.net> - 2017-02-13 15:28 +0000
  Re: How to increase the volume of a metronome? Tim Wescott <tim@seemywebsite.com> - 2017-02-13 11:15 -0600
    Re: How to increase the volume of a metronome? Don Kuenz <g@crcomp.net> - 2017-02-13 19:28 +0000
  Re: How to increase the volume of a metronome? Don Y <blockedofcourse@foo.invalid> - 2017-02-13 11:21 -0700
    Re: How to increase the volume of a metronome? Don Kuenz <g@crcomp.net> - 2017-02-13 19:28 +0000
      Re: How to increase the volume of a metronome? Don Y <blockedofcourse@foo.invalid> - 2017-02-13 13:00 -0700
  Re: How to increase the volume of a metronome? bitrex <bitrex@de.lete.earthlink.net> - 2017-02-13 13:42 -0500
    Re: How to increase the volume of a metronome? Don Kuenz <g@crcomp.net> - 2017-02-13 19:58 +0000
  Re: How to increase the volume of a metronome? Tim Wescott <seemywebsite@myfooter.really> - 2017-02-13 12:43 -0600
    Re: How to increase the volume of a metronome? Don Kuenz <g@crcomp.net> - 2017-02-13 19:47 +0000
    Re: How to increase the volume of a metronome? bitrex <bitrex@de.lete.earthlink.net> - 2017-02-13 18:05 -0500
  Re: How to increase the volume of a metronome? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-02-13 21:30 +0200
    Re: How to increase the volume of a metronome? Don Kuenz <g@crcomp.net> - 2017-02-13 19:54 +0000
      Re: How to increase the volume of a metronome? Don Kuenz <g@crcomp.net> - 2017-02-23 05:54 +0000
        Re: How to increase the volume of a metronome? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-02-23 16:43 +0200
          Re: How to increase the volume of a metronome? Don Kuenz <g@crcomp.net> - 2017-02-23 15:23 +0000
            Re: How to increase the volume of a metronome? tabbypurr@gmail.com - 2017-02-23 16:29 -0800
              Re: How to increase the volume of a metronome? Don Kuenz <g@crcomp.net> - 2017-02-24 02:15 +0000
                Re: How to increase the volume of a metronome? tabbypurr@gmail.com - 2017-02-24 01:49 -0800
                Re: How to increase the volume of a metronome? Don Kuenz <g@crcomp.net> - 2017-02-24 14:56 +0000
                Re: How to increase the volume of a metronome? tabbypurr@gmail.com - 2017-02-24 07:21 -0800
                Re: How to increase the volume of a metronome? rickman <gnuarm@gmail.com> - 2017-02-24 14:11 -0500
                Re: How to increase the volume of a metronome? rickman <gnuarm@gmail.com> - 2017-02-24 15:28 -0500
                Re: How to increase the volume of a metronome? tabbypurr@gmail.com - 2017-02-24 12:37 -0800
                Re: How to increase the volume of a metronome? rickman <gnuarm@gmail.com> - 2017-02-24 15:46 -0500
                Re: How to increase the volume of a metronome? tabbypurr@gmail.com - 2017-02-24 13:23 -0800
                Re: How to increase the volume of a metronome? rickman <gnuarm@gmail.com> - 2017-02-24 17:49 -0500
                Re: How to increase the volume of a metronome? Don Kuenz <g@crcomp.net> - 2017-02-25 03:43 +0000
                Re: How to increase the volume of a metronome? tabbypurr@gmail.com - 2017-02-24 23:03 -0800
                Re: How to increase the volume of a metronome? rickman <gnuarm@gmail.com> - 2017-02-25 03:20 -0500
  Re: How to increase the volume of a metronome? Jasen Betts <jasen@xnet.co.nz> - 2017-02-15 11:11 +0000

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