Help Me With My OCL AMP Design, Thanks
How Can I design a OCL AMP?
Is it possible to put mutiple transitors together in diffrent configurations and then it will work?
using common emiter set up then a common collecter set up
I had shorted the output of pnp and npn trasntiors, it works fine and has the correct idle current which I wanted it to be, 20MA.
Plorbem is that I am getting no sound. I have excatly 0 volts in the speaker
but it is not amplifiing any sound
TransistorAmp circuit design software for bipolar transistor amplifiers
I used trasntior amp for design but I haven't used any load resitors.
I am guessing even if I had used load resitors it wouldn't work
Load resitors i am reffering to for common emiter is r3
Howto design a transistor amp in common-emitter configuration with TransistorAmp 1.1 software
and also r3 for common collector
Howto design a transistor amp in common-collector configuration with TransistorAmp 1.1 software
How Can I design a OCL AMP?
Is it possible to put mutiple transitors together in diffrent configurations and then it will work?
using common emiter set up then a common collecter set up
I had shorted the output of pnp and npn trasntiors, it works fine and has the correct idle current which I wanted it to be, 20MA.
Plorbem is that I am getting no sound. I have excatly 0 volts in the speaker
but it is not amplifiing any sound
TransistorAmp circuit design software for bipolar transistor amplifiers
I used trasntior amp for design but I haven't used any load resitors.
I am guessing even if I had used load resitors it wouldn't work
Load resitors i am reffering to for common emiter is r3
Howto design a transistor amp in common-emitter configuration with TransistorAmp 1.1 software
and also r3 for common collector
Howto design a transistor amp in common-collector configuration with TransistorAmp 1.1 software
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Are you trying to make a direct-coupled power amplifier? That is the most common type, for many years now.
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The simple trick with such an amplifier is to use a large capacitor in the ground leg of the nfb network.
This reduces the gain to unity at DC, so that the input offset voltage is not multiplied by the AC gain.
Most audio amplifiers do this. A random example: http://i2.wp.com/circuitszone.com/w...reo-amplifier-based-LM1876.jpg?resize=350,200
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works like a charm..Whats happening here is that I am having no sound at all.
I don't have a feed back loop either, just trying to get some sound comming out of the speaker.
I'm tyring to use a common emiter setup to gain some voltage then feed that into a common collecter set up. then use npn and a pnp to make it ocl.
I have the out puts of the emiter and collector set up shorted, so the dc voltage is zero since the trasntiors will give out the dc voltage at the out put due to the dc voltaged usied to bias it, thefore it needs a capacitor at the out put to block the dc voltage.
I don't have a feed back loop either, just trying to get some sound comming out of the speaker.
I'm tyring to use a common emiter setup to gain some voltage then feed that into a common collecter set up. then use npn and a pnp to make it ocl.
I have the out puts of the emiter and collector set up shorted, so the dc voltage is zero since the trasntiors will give out the dc voltage at the out put due to the dc voltaged usied to bias it, thefore it needs a capacitor at the out put to block the dc voltage.
An amplifier cannot amplifiy a signal it never gets, apply a signal to the input then trace it through the amp. Does it get to the base/gate of the outputs, does it get to the drivers?
You have referred us to a number of circuit tutorials, but please make a drawing of exactly what you BUILT, and post it.
You have referred us to a number of circuit tutorials, but please make a drawing of exactly what you BUILT, and post it.
Thanks for the help guys, heres what I had built.
I had also tried chaging to a common base instead of emiter for the voltage gain stage.
Since I thought 50k input inpediance could be too high so i am getting no sound.
The common base had 1.3ohms input inpediance but no sound either
same idle current, both sides postive and negative side idle current is at 20ma, seems a bit odd though
should I be getting 40ma both sides instead of 20?
Also if I tap the speaker, it seems to be stuck in the middle,
and it i push the speaker in and out enough the back voltage caused by the inducatance of the speaker will blow my tip41c
refer to the circuit with just the circuit diagram,
I had also tried chaging to a common base instead of emiter for the voltage gain stage.
Since I thought 50k input inpediance could be too high so i am getting no sound.
The common base had 1.3ohms input inpediance but no sound either
same idle current, both sides postive and negative side idle current is at 20ma, seems a bit odd though
should I be getting 40ma both sides instead of 20?
Also if I tap the speaker, it seems to be stuck in the middle,
and it i push the speaker in and out enough the back voltage caused by the inducatance of the speaker will blow my tip41c
refer to the circuit with just the circuit diagram,
Attachments
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Sorry for the doubble post, but it dosen't seem like I can edit my old post any more
Heres the two solutions I had come up with, which could solve the plorbems but I have not tried them yet.
What I would do is remove the shorted together outputs of the common emiter stage, then add a load resitor, input to next stage, but then next stage dosen't have any biasing resitors then connect to speakrers.
The other solution is doing the same thing as above but not having a load resitor
Heres the two solutions I had come up with, which could solve the plorbems but I have not tried them yet.
What I would do is remove the shorted together outputs of the common emiter stage, then add a load resitor, input to next stage, but then next stage dosen't have any biasing resitors then connect to speakrers.
The other solution is doing the same thing as above but not having a load resitor
So I currently have the drivers connected in common base operation
removed the shorted out puts of the and shorted inputs of the common base configuration.
I then feed the output of common base into the common collector without any biasing transitors, inserted a 33 ohm reistor load and powerd up. Zero idle current flowing
Seems like the plorbem here is the common base or common emitter configuration biasing is not working porperly? I have connected every thing up using the diagram I got from transitor amp, but have not connected a load resitor.
So it seems like currently, the side on the right is working fine, common collecter set up. but the stuff on the left is not ok.
Added the load resitor, and it seems to be biasing the common collecter transitors with too much voltage
(instead of working as a load resitor it became the biasing resitor instead),
I am getting 0.5Amps and 0.7Amps on postibe and negative supply. Used a 1K for load resitor and transitor amp says the value should be 1.3K
I know common collector setup has no voltage gain, does it have enough gain to put out some sound?
Would it have enough gain if I use a few stages of common collector setup folowed by common collector set up
removed the shorted out puts of the and shorted inputs of the common base configuration.
I then feed the output of common base into the common collector without any biasing transitors, inserted a 33 ohm reistor load and powerd up. Zero idle current flowing
Seems like the plorbem here is the common base or common emitter configuration biasing is not working porperly? I have connected every thing up using the diagram I got from transitor amp, but have not connected a load resitor.
So it seems like currently, the side on the right is working fine, common collecter set up. but the stuff on the left is not ok.
Added the load resitor, and it seems to be biasing the common collecter transitors with too much voltage
(instead of working as a load resitor it became the biasing resitor instead),
I am getting 0.5Amps and 0.7Amps on postibe and negative supply. Used a 1K for load resitor and transitor amp says the value should be 1.3K
I know common collector setup has no voltage gain, does it have enough gain to put out some sound?
Would it have enough gain if I use a few stages of common collector setup folowed by common collector set up
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