Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > sci.electronics.design > #447552 > unrolled thread

How to increase the volume of a metronome?

Back to article view | Back to sci.electronics.design

Contents

  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

Page 2 of 2 — ← Prev page 1 [2]

#449033

On Friday, 24 February 2017 14:58:54 UTC, Don Kuenz  wrote:
> tabbypurr wrote:
> > On Friday, 24 February 2017 02:17:12 UTC, Don Kuenz  wrote:
> >> tabbypurr wrote:
> >
> >> > Your asc won't run at all on this machine, no idea why.
> >>
> >> This zip file ought to contain everything you need:
> >>
> >> http://crcomp.net/Diary/metronome.zip
> >>
> >> Thank you,
> >
> > Cheers, works nicely.
> >
> > Your output voltages are lousy compared to the 9v supply.
> >
> > Replacing the 386 and using a transistor output would get you much
> > better swing. But of course it requires other changes to avoid feeding
> > the speaker dc or only operating on one of the 555's transitions.
> > There are a few possible ways to do that. You also don't need the
> > zobel if you're just switching it and using no nfb.
> >
> > Harmonics help with volume. You might inject some at each opportunity,
> > eg output of 555 then again with passives across the speaker. Low duty
> > cycle there should help with power requirements.
> >
> > If you go with added digital logic to process the 555 output into a
> > rising edge at each 555 transition you might add some ringing there.
> > The speaker housing can also be thin and somewhat resonant.
> >
> > I'm assuming you don't need to go to BTL or higher psu voltage.
> 
> You gave me lots of food for thought. The metronome was originally
> conceived to be DIY quick and dirty. Your post may motivate me to try
> harder.
> 
> Sharing this project has been a learning experience for me in many ways.
> In the future, for example, my web server will host all .asc files. The
> "standalone" nature of a usenet post appealed to me, but it's fraught
> with too many ?Windows? gotchas.
> 
> My original circuit used a transistor, a 2N3904. But it outputted too
> low of a volume, ergo this thread. FWIW, my metronome with a transistor
> is available here:
> 
> http://crcomp.net/Diary/metronome3.asc
> 
> Thank you,

Put the speaker in the collector line and you'd get more volume. 
Digital logic is probably the best option, but not the only one. You could probably make it work without the dc by having both npn & pnp trs with CR on their bases. Either transition causes one to pass a single shot of speaker current.
You could probably implement the whole lot with a hex buffer plus an output transistor, no 555.

At 200mA max, 2N3904 is way underrated. You'd need a 2A transistor at least.


NT

[toc] | [prev] | [next] | [standalone]

#449060

On 2/24/2017 9:56 AM, Don Kuenz wrote:
> tabbypurr@gmail.com wrote:
>> On Friday, 24 February 2017 02:17:12 UTC, Don Kuenz  wrote:
>>> tabbypurr wrote:
>>
>>>> Your asc won't run at all on this machine, no idea why.
>>>
>>> This zip file ought to contain everything you need:
>>>
>>> http://crcomp.net/Diary/metronome.zip
>>>
>>> Thank you,
>>
>> Cheers, works nicely.
>>
>> Your output voltages are lousy compared to the 9v supply.
>>
>> Replacing the 386 and using a transistor output would get you much
>> better swing. But of course it requires other changes to avoid feeding
>> the speaker dc or only operating on one of the 555's transitions.
>> There are a few possible ways to do that. You also don't need the
>> zobel if you're just switching it and using no nfb.
>>
>> Harmonics help with volume. You might inject some at each opportunity,
>> eg output of 555 then again with passives across the speaker. Low duty
>> cycle there should help with power requirements.
>>
>> If you go with added digital logic to process the 555 output into a
>> rising edge at each 555 transition you might add some ringing there.
>> The speaker housing can also be thin and somewhat resonant.
>>
>> I'm assuming you don't need to go to BTL or higher psu voltage.
>
> You gave me lots of food for thought. The metronome was originally
> conceived to be DIY quick and dirty. Your post may motivate me to try
> harder.
>
> Sharing this project has been a learning experience for me in many ways.
> In the future, for example, my web server will host all .asc files. The
> "standalone" nature of a usenet post appealed to me, but it's fraught
> with too many ?Windows? gotchas.
>
> My original circuit used a transistor, a 2N3904. But it outputted too
> low of a volume, ergo this thread. FWIW, my metronome with a transistor
> is available here:
>
> http://crcomp.net/Diary/metronome3.asc

I'm not sure all the comments about this circuit are important.  Adding 
a cap and diode to the base drive turns the positive edge into a sharp 
pulse.  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.

-- 

Rick C

[toc] | [prev] | [next] | [standalone]

#449067

On 2/24/2017 2:11 PM, rickman wrote:
> On 2/24/2017 9:56 AM, Don Kuenz wrote:
>> tabbypurr@gmail.com wrote:
>>> On Friday, 24 February 2017 02:17:12 UTC, Don Kuenz  wrote:
>>>> tabbypurr wrote:
>>>
>>>>> Your asc won't run at all on this machine, no idea why.
>>>>
>>>> This zip file ought to contain everything you need:
>>>>
>>>> http://crcomp.net/Diary/metronome.zip
>>>>
>>>> Thank you,
>>>
>>> Cheers, works nicely.
>>>
>>> Your output voltages are lousy compared to the 9v supply.
>>>
>>> Replacing the 386 and using a transistor output would get you much
>>> better swing. But of course it requires other changes to avoid feeding
>>> the speaker dc or only operating on one of the 555's transitions.
>>> There are a few possible ways to do that. You also don't need the
>>> zobel if you're just switching it and using no nfb.
>>>
>>> Harmonics help with volume. You might inject some at each opportunity,
>>> eg output of 555 then again with passives across the speaker. Low duty
>>> cycle there should help with power requirements.
>>>
>>> If you go with added digital logic to process the 555 output into a
>>> rising edge at each 555 transition you might add some ringing there.
>>> The speaker housing can also be thin and somewhat resonant.
>>>
>>> I'm assuming you don't need to go to BTL or higher psu voltage.
>>
>> You gave me lots of food for thought. The metronome was originally
>> conceived to be DIY quick and dirty. Your post may motivate me to try
>> harder.
>>
>> Sharing this project has been a learning experience for me in many ways.
>> In the future, for example, my web server will host all .asc files. The
>> "standalone" nature of a usenet post appealed to me, but it's fraught
>> with too many ?Windows? gotchas.
>>
>> My original circuit used a transistor, a 2N3904. But it outputted too
>> low of a volume, ergo this thread. FWIW, my metronome with a transistor
>> is available here:
>>
>> http://crcomp.net/Diary/metronome3.asc
>
> I'm not sure all the comments about this circuit are important.  Adding
> a cap and diode to the base drive turns the positive edge into a sharp
> pulse.  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.

Version 4
SHEET 1 960 936
WIRE -384 96 -512 96
WIRE -288 96 -384 96
WIRE 64 96 -288 96
WIRE 112 96 64 96
WIRE 496 96 112 96
WIRE 112 112 112 96
WIRE -384 128 -384 96
WIRE -288 192 -288 96
WIRE -240 192 -288 192
WIRE 112 192 112 176
WIRE 112 192 -16 192
WIRE 112 224 112 192
WIRE -384 256 -384 208
WIRE -240 256 -384 256
WIRE 16 256 -16 256
WIRE -384 304 -384 256
WIRE -240 320 -320 320
WIRE 176 320 -16 320
WIRE 176 336 176 320
WIRE -240 384 -288 384
WIRE 64 384 64 96
WIRE 64 384 -16 384
WIRE 496 400 496 96
WIRE -384 448 -384 384
WIRE -320 448 -320 320
WIRE -320 448 -384 448
WIRE 16 448 16 256
WIRE 16 448 -320 448
WIRE 176 448 176 416
WIRE 240 448 176 448
WIRE 272 448 240 448
WIRE 368 448 336 448
WIRE 432 448 368 448
WIRE -512 464 -512 96
WIRE -384 464 -384 448
WIRE -288 464 -288 384
WIRE 176 496 176 448
WIRE 496 512 496 496
WIRE 368 528 368 448
WIRE 496 528 496 512
WIRE -512 592 -512 544
WIRE -384 592 -384 528
WIRE -384 592 -512 592
WIRE -288 592 -288 528
WIRE -288 592 -384 592
WIRE 176 624 176 576
WIRE 368 624 368 592
WIRE 496 624 496 608
WIRE -512 640 -512 592
FLAG -512 640 0
FLAG 112 224 0
FLAG 176 624 0
FLAG 496 624 0
FLAG 368 448 Base
FLAG 240 448 Cap
FLAG 496 512 Spkr
FLAG 368 624 0
SYMBOL Misc\\NE555 -128 288 M0
SYMATTR InstName U1
SYMBOL res -368 112 M0
SYMATTR InstName Tempo1
SYMATTR Value 125k
SYMBOL res -368 288 M0
WINDOW 0 36 43 Left 2
WINDOW 3 49 74 Left 2
SYMATTR InstName Tempo2
SYMATTR Value 125k
SYMBOL cap -368 464 M0
WINDOW 0 -23 6 Left 2
WINDOW 3 -41 58 Left 2
SYMATTR InstName C2
SYMATTR Value 2.2µF
SYMBOL res 160 320 R0
WINDOW 0 -59 39 Left 2
WINDOW 3 -58 71 Left 2
SYMATTR InstName Vol1
SYMATTR Value 5
SYMBOL Misc\\battery -512 448 R0
WINDOW 0 11 6 Left 2
WINDOW 3 5 126 Left 2
WINDOW 123 0 0 Left 2
WINDOW 39 5 98 Left 2
SYMATTR InstName V1
SYMATTR Value PULSE(0 9 0 0.001)
SYMATTR SpiceLine Rser=2
SYMBOL cap -304 464 R0
SYMATTR InstName C3
SYMATTR Value 0.1nF
SYMBOL cap 96 112 R0
SYMATTR InstName C4
SYMATTR Value 10µF
SYMBOL res 160 480 R0
WINDOW 0 -57 41 Left 2
WINDOW 3 -59 68 Left 2
SYMATTR InstName Vol2
SYMATTR Value 995
SYMBOL npn 432 400 R0
SYMATTR InstName Q1
SYMATTR Value 2N3904
SYMBOL res 480 512 R0
SYMATTR InstName Speaker
SYMATTR Value 8
SYMBOL cap 272 464 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName C1
SYMATTR Value 1µF
SYMBOL schottky 384 592 R180
WINDOW 0 24 64 Left 2
WINDOW 3 24 0 Left 2
SYMATTR InstName D1
SYMATTR Value BAT54
SYMATTR Description Diode
SYMATTR Type diode
TEXT -392 616 Right 2 !.tran 1 uic
TEXT -8 176 Left 2 ;1
TEXT -8 240 Left 2 ;2
TEXT -8 304 Left 2 ;3
TEXT -8 360 Left 2 ;4
TEXT -296 368 Left 2 ;5
TEXT -296 304 Left 2 ;6
TEXT -296 240 Left 2 ;7
TEXT -296 176 Left 2 ;8


-- 

Rick C

[toc] | [prev] | [next] | [standalone]

#449069

On Friday, 24 February 2017 19:11:25 UTC, rickman  wrote:
> On 2/24/2017 9:56 AM, Don Kuenz wrote:
> > tabbypurr wrote:
> >> On Friday, 24 February 2017 02:17:12 UTC, Don Kuenz  wrote:
> >>> tabbypurr wrote:
> >>
> >>>> Your asc won't run at all on this machine, no idea why.
> >>>
> >>> This zip file ought to contain everything you need:
> >>>
> >>> http://crcomp.net/Diary/metronome.zip
> >>>
> >>> Thank you,
> >>
> >> Cheers, works nicely.
> >>
> >> Your output voltages are lousy compared to the 9v supply.
> >>
> >> Replacing the 386 and using a transistor output would get you much
> >> better swing. But of course it requires other changes to avoid feeding
> >> the speaker dc or only operating on one of the 555's transitions.
> >> There are a few possible ways to do that. You also don't need the
> >> zobel if you're just switching it and using no nfb.
> >>
> >> Harmonics help with volume. You might inject some at each opportunity,
> >> eg output of 555 then again with passives across the speaker. Low duty
> >> cycle there should help with power requirements.
> >>
> >> If you go with added digital logic to process the 555 output into a
> >> rising edge at each 555 transition you might add some ringing there.
> >> The speaker housing can also be thin and somewhat resonant.
> >>
> >> I'm assuming you don't need to go to BTL or higher psu voltage.
> >
> > You gave me lots of food for thought. The metronome was originally
> > conceived to be DIY quick and dirty. Your post may motivate me to try
> > harder.
> >
> > Sharing this project has been a learning experience for me in many ways.
> > In the future, for example, my web server will host all .asc files. The
> > "standalone" nature of a usenet post appealed to me, but it's fraught
> > with too many ?Windows? gotchas.
> >
> > My original circuit used a transistor, a 2N3904. But it outputted too
> > low of a volume, ergo this thread. FWIW, my metronome with a transistor
> > is available here:
> >
> > http://crcomp.net/Diary/metronome3.asc
> 
> I'm not sure all the comments about this circuit are important.  Adding 
> a cap and diode to the base drive turns the positive edge into a sharp 
> pulse. 

But then he'll only hear every other edge. That's fine if the OP doesn't mind losing the ability to hahve different mark/space ratios, but I presumed from his design that wasn't the case.

> 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.


NT

[toc] | [prev] | [next] | [standalone]

#449071

On 2/24/2017 3:37 PM, tabbypurr@gmail.com wrote:
> On Friday, 24 February 2017 19:11:25 UTC, rickman  wrote:
>> On 2/24/2017 9:56 AM, Don Kuenz wrote:
>>> tabbypurr wrote:
>>>> On Friday, 24 February 2017 02:17:12 UTC, Don Kuenz  wrote:
>>>>> tabbypurr wrote:
>>>>
>>>>>> Your asc won't run at all on this machine, no idea why.
>>>>>
>>>>> This zip file ought to contain everything you need:
>>>>>
>>>>> http://crcomp.net/Diary/metronome.zip
>>>>>
>>>>> Thank you,
>>>>
>>>> Cheers, works nicely.
>>>>
>>>> Your output voltages are lousy compared to the 9v supply.
>>>>
>>>> Replacing the 386 and using a transistor output would get you much
>>>> better swing. But of course it requires other changes to avoid feeding
>>>> the speaker dc or only operating on one of the 555's transitions.
>>>> There are a few possible ways to do that. You also don't need the
>>>> zobel if you're just switching it and using no nfb.
>>>>
>>>> Harmonics help with volume. You might inject some at each opportunity,
>>>> eg output of 555 then again with passives across the speaker. Low duty
>>>> cycle there should help with power requirements.
>>>>
>>>> If you go with added digital logic to process the 555 output into a
>>>> rising edge at each 555 transition you might add some ringing there.
>>>> The speaker housing can also be thin and somewhat resonant.
>>>>
>>>> I'm assuming you don't need to go to BTL or higher psu voltage.
>>>
>>> You gave me lots of food for thought. The metronome was originally
>>> conceived to be DIY quick and dirty. Your post may motivate me to try
>>> harder.
>>>
>>> Sharing this project has been a learning experience for me in many ways.
>>> In the future, for example, my web server will host all .asc files. The
>>> "standalone" nature of a usenet post appealed to me, but it's fraught
>>> with too many ?Windows? gotchas.
>>>
>>> My original circuit used a transistor, a 2N3904. But it outputted too
>>> low of a volume, ergo this thread. FWIW, my metronome with a transistor
>>> is available here:
>>>
>>> http://crcomp.net/Diary/metronome3.asc
>>
>> I'm not sure all the comments about this circuit are important.  Adding
>> a cap and diode to the base drive turns the positive edge into a sharp
>> pulse.
>
> But then he'll only hear every other edge. That's fine if the OP doesn't mind losing the ability to hahve different mark/space ratios, but I presumed from his design that wasn't the case.
>
>> 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.

-- 

Rick C

[toc] | [prev] | [next] | [standalone]

#449076

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.


NT

[toc] | [prev] | [next] | [standalone]

#449083

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. 
BTW, I reduced the cap to 10 uF.  It's just a freakin metronome.

-- 

Rick C

[toc] | [prev] | [next] | [standalone]

#449126

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

[toc] | [prev] | [next] | [standalone]

#449134

On Saturday, 25 February 2017 03:45:26 UTC, Don Kuenz  wrote:
> rickman <gnuarm@gmail.com> wrote:
> > On 2/24/2017 4:23 PM, tabbypurr 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,

You don't need to waste current with a single transistor output, just have the 555 output a short fixed length pulse when it goes high rather than a long variable one. 100uF seems small for battery use.

Compared to AA or AAA, 9v PP3s are low capacity and high price per capacity. I avoid using them when practical.


NT

[toc] | [prev] | [next] | [standalone]

#449141

On 2/24/2017 10:43 PM, Don Kuenz wrote:
>
> 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)

I tried something a bit different, a simpler design.  Personally, if I 
were going to do anything more complex than this, I would use an MPU 
which will give you dead accurate timing and volume independent of 
battery state, wall wart or anything else plus the sound can be 
controlled both in volume and tone.  But this design only has two 
transistors and a few passives and should give you a decent sound.  The 
power consumption is very low, 8 mA (average) on the fastest setting 
(about 5 beats per second) giving a life of well over 60 hours from a 9 
volt battery in normal use.

The speaker gets a pulse that is only a few ms wide, but the current is 
controlled rather than the pulse width.  So the sound will remain the 
same over the full volume.  Here is the LTspice file.  You will need the 
files for the 2N2426 component too.  Run using the alternate solver.

----nujt.asy----
Version 4
SymbolType CELL
LINE Normal 24 16 24 80
LINE Normal 48 72 48 96
LINE Normal 24 72 48 72
LINE Normal 48 24 48 0
LINE Normal 24 24 48 24
LINE Normal 6 44 12 36
LINE Normal 6 44 24 53
LINE Normal 12 36 24 53
LINE Normal 0 32 9 40
LINE Normal -16 32 0 32
WINDOW 0 56 32 Left 0
WINDOW 3 56 72 Left 0
SYMATTR Value UJT
SYMATTR Prefix X
SYMATTR Description N-Channel Unijunction Transistor, Netlist order E, 
B1, B2
PIN -16 32 NONE 0
PINATTR PinName E
PINATTR SpiceOrder 1
PIN 48 96 NONE 0
PINATTR PinName B1
PINATTR SpiceOrder 2
PIN 48 0 NONE 0
PINATTR PinName B2
PINATTR SpiceOrder 3

----2n2646.sub----
* Transistor unijonction N  (1)E Emetteur, (2)B1 Base 1, (3)B2 Base 2
* IP=.5U IV=6M VB1(sat)=3 Rbb=6.1K Vob1=3.6  MFG=Motorola
.SUBCKT X2N2646 E B1 B2
DE E 4 EMITTER
VE 4 5 DC 0
HVE 6 0 VE 1K
RVE 0 6 1MEG
*BBB 5 7 I=0.00028*V(5,7)+0.00575*V(5,7)*V(6,0)
GBB 5 7 poly(2) (5,7) (6,0) 0 0.00028 0 0 0.00575
CBB 5 7 35P
RB1 7 B1 RMOD 38.15
RB2 B2 5 RMOD 2.518K
.MODEL RMOD RES(R=1,TC1=0.01)
.MODEL EMITTER D (IS=21.3P N=1.8)
.ENDS

----Metronome_UJT.asc----
Version 4
SHEET 1 1992 3388
WIRE -448 368 -624 368
WIRE -352 368 -448 368
WIRE -288 368 -352 368
WIRE -64 368 -288 368
WIRE -64 400 -64 368
WIRE -288 416 -288 368
WIRE -448 432 -448 368
WIRE -64 528 -64 480
WIRE -624 544 -624 368
WIRE -288 560 -288 496
WIRE -240 560 -288 560
WIRE -288 576 -288 560
WIRE -64 592 -64 528
WIRE -448 608 -448 512
WIRE -384 608 -448 608
WIRE -352 608 -384 608
WIRE -128 640 -160 640
WIRE -448 704 -448 608
WIRE -288 704 -288 672
WIRE -208 704 -288 704
WIRE -160 704 -160 640
WIRE -160 704 -208 704
WIRE -64 736 -64 688
WIRE -288 752 -288 704
WIRE -64 784 -64 736
WIRE -624 896 -624 624
WIRE -448 896 -448 768
WIRE -448 896 -624 896
WIRE -288 896 -288 832
WIRE -288 896 -448 896
WIRE -64 896 -64 864
WIRE -64 896 -288 896
WIRE -624 928 -624 896
FLAG -624 928 0
FLAG -384 608 E1
FLAG -208 704 B1
FLAG -240 560 B2
FLAG -352 368 V9
FLAG -64 528 SPKR
FLAG -64 736 VOL
SYMBOL voltage -624 528 R0
WINDOW 123 0 0 Left 2
WINDOW 39 24 124 Left 2
SYMATTR SpiceLine Rser=1
SYMATTR InstName V1
SYMATTR Value 9
SYMBOL nujt -336 576 R0
SYMATTR InstName U2
SYMATTR Value X2N2646
SYMATTR Description N-Channel Unijunction Transistor
SYMBOL res -304 400 R0
SYMATTR InstName R1
SYMATTR Value 100
SYMBOL res -304 736 R0
SYMATTR InstName R2
SYMATTR Value 100
SYMBOL res -464 416 R0
SYMATTR InstName SPEED
SYMATTR Value 25k
SYMBOL cap -464 704 R0
SYMATTR InstName C1
SYMATTR Value 10µ
SYMBOL npn -128 592 R0
SYMATTR InstName Q1
SYMATTR Value 2SCR512P
SYMBOL res -80 384 R0
SYMATTR InstName SPKR
SYMATTR Value 5.2
SYMBOL res -80 768 R0
SYMATTR InstName VOL
SYMATTR Value 1
TEXT -640 248 Left 2 !.tran 0 2 0 .01m
TEXT -640 280 Left 2 !.options plotwinsize=0
TEXT -640 312 Left 2 ;.options trtol=1e-1
TEXT -640 -200 Left 2 ;Unijunction Transistor 2N2646\n \nUse the 
Alternate-solver.\nControl Panel -> SPICE -> Solver:Alternate\n \nThe 
discharge slope is too steep at the end and thus a very small\ntime step 
would be required to improve the simulation accuracy\nof the lower 
peaks. This is a model issue!
TEXT -336 248 Left 2 !.include 2n2646_ltspice.sub
TEXT -640 48 Left 2 ;A small modification of the model has been required 
for 
LTspice.\nhttp://www.duncanamps.com/spice/miscsemi/2n2646.sub\n***RB1 7 
2 38.15 RMOD\n***RB2 3 5 2.518K RMOD \nRB1 7 2 RMOD 38.15 \nRB2 3 5 RMOD 
2.518K
TEXT -40 720 Left 2 ;Volume Control - 0 to 100 ohms gives \n1.2 Amp to 6 
mA to speaker.
TEXT -320 304 Left 2 ;Speed control - 25 kohms to 250 kohms gives 
\nabout 5 beats per second to 1 beat in 2 seconds.


-- 

Rick C

[toc] | [prev] | [next] | [standalone]

#447723

On 2017-02-13, Don Kuenz <g@crcomp.net> wrote:
>
> Greetings,
>
> Comments are sought on additional circuitry to increase the speaker
> volume of the circuit shown between the lines. Comments on circuit
> simplifications are also sought. (Maybe a 555 with a couple of pots is
> as simple as it gets sometimes?)
>
> The Tempo1/Tempo2 resistor pair signifies a pot as does the Vol1/Vol2
> pair. Is there a better way to capture pots with LTSpice?

 use a stronger transistor, eg TIP31, 2N3055, etc.
 a 4 ohm speaker.
 and increase the supply voltage to 12V 

a capacitor in series with pin3 and a diode up from ground will save
much energy. maybe start with 100nF and increase it if that's too quiet.

if that's still not enough, you'll want a real audio amplifier... 
(actually you probably want a real audio amp as it is).

-- 
This email has not been checked by half-arsed antivirus software 

[toc] | [prev] | [standalone]

Page 2 of 2 — ← Prev page 1 [2]

Back to top | Article view | sci.electronics.design

csiph-web