Signal amplifier works

Uncle Steve · 2013-02-08T19:14:08+00:00

... unless there is no signal at the input. I started with some information at the following two URLS: The first URL goes through the process of building a high-gain amplifier, and it works O.K. with the exception that there is no power. The second URL goes into more detail and shows how to deliver some power to the speaker as in figure 16. I have different parts on hand, and I am working with a 12V supply instead of 9V as in the first URL. Since I am looking to deliver big chunky volts to my speaker, I went ahead and modified Figure 16 and the example in the first URL to obtain the following circuit: 12V +---+----------+----------+ R1 = 510K | | | | R2 = 5.9K | > R2 > R3 | R3 = 220 R1 > < < | C1 = 1uF < | | | Q1, Q2 = 2N2222 | +-- | | Q3 = 2N3055 input | | b |c | o---||-+-(Q1) -----(Q2) -----(Q3) C1 | |e / | 1uf | --- SPKR | | | | o----------+---------------------+ SPKR is a ribbon tweeter with a 2 Ohm, 10 Watt resistor in series. R2 ought to be 6K, but 5.9 is what I have on hand. Driving the circuit with a 50KHz signal produces 10V across the speaker, which decreases to about 8V as the power transistor heats up. I had a problem with thermal runaway until I got a sufficiently beefy heatsink on Q3 and the 7812 supplying the 12V rail. Q3 runs quite hot, but I think I can fix that by substituting a TO-3 package for the TO-220 currently in the circuit, or by reducing the current. Not sure which is the proper solution, but the speaker handles the existing power. 220 Ohms for R3 was derived by guessing, and noting that 1K attenuates the signal too much, but I don't really know how I should be calculating the proper value. The speaker is usually paired with a 5.1 Ohm, 5W...

J

John Larkin 13 years ago

There are infinitely many, and they are being created much faster than you can zap them.

John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators

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J

John Larkin 13 years ago

is

electron

deliver

on

first

A minute minority of electronic circuits, arguably none of them, are trivial.

That's one reason why there are so many bad circuits, and bad circuit designers, around.

John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators

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U

Uncle Steve 13 years ago

worst.

is

electron

that

electrons

beginner

deliver

on

first

speaker,

URL

worked,

a

the

circuits

can

and

depending

Ebers-Moll

It must be difficult, hating your self so much that you cannot entertain the idea of normal relations with normal people.

Regards,

Uncle Steve

More than a century has passed since science laid down sound propositions as to the origins of the universe, but how many have mastered them or possess the really scientific spirit of criticism? A few thousands at the outside, who are lost in the midst of hundreds of millions still steeped in prejudices and superstitions worthy of savages, who are consequently ever ready to serve as puppets for religious impostors. -- Peter Kropotkin

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Uncle Steve 13 years ago

I know. It's difficult not to overshoot. One of the reasons why I'm keen on analogue electronics. The "STOP DESTROYING UNIVERSES" button needs a little debouncing and ideally should have some safety features. The crude lash-up I'm currently using works, but is highly suboptimal.

Regards,

Uncle Steve

More than a century has passed since science laid down sound propositions as to the origins of the universe, but how many have mastered them or possess the really scientific spirit of criticism? A few thousands at the outside, who are lost in the midst of hundreds of millions still steeped in prejudices and superstitions worthy of savages, who are consequently ever ready to serve as puppets for religious impostors. -- Peter Kropotkin

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J

Jim Thompson 13 years ago

worst.

guy is

electron

they

that

obscures

electrons

beginner

deliver

parts on

first

speaker,

URL

series.

a

worked,

a

the

circuits

can

and

depending

comes

Ebers-Moll

Like all lefties, you didn't address the question... you dodged. You're a loser... face it. ...Jim Thompson

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K

krw 13 years ago

worst.

guy is

electron

they

that

obscures

electrons

beginner

deliver

parts on

first

speaker,

URL

series.

a

worked,

a

the

circuits

can

and

depending

comes

Ebers-Moll

Of course, like all lefties, you're clueless. It's evident that you're really not here to learn anything about electronics so it would probably be a wise idea to leave, now. Though wise and lefty certainly don't belong in the same paragraph.

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U

Uncle Steve 13 years ago

worst.

guy is

electron

actually

An

as

they

that

makes

this

the

obscures

electrons

doubt

beginner

than

like

no

deliver

parts on

the first

speaker,

first URL

series.

of a

worked,

had a

transistors

to the

circuits

can

thousand, and

depending

almost

comes

Ebers-Moll

electronics,

Characteristic projection of your own prejudices on others. Clearly you're not here to discuss matters of basic electronics in a civil fashion unless with people who agree with every one of your delusional prejudices.

FTR, I'm not a Leftist but I play them on the Internet.

Regards,

Uncle Steve

More than a century has passed since science laid down sound propositions as to the origins of the universe, but how many have mastered them or possess the really scientific spirit of criticism? A few thousands at the outside, who are lost in the midst of hundreds of millions still steeped in prejudices and superstitions worthy of savages, who are consequently ever ready to serve as puppets for religious impostors. -- Peter Kropotkin

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J

Jim Thompson 13 years ago

Bwahahahahahaha!

You've not presented any "basic electronics" here.

Just BS that is totally incorrect.

And you're clearly not interested in actually learning, rejecting any suggestions from those of us who have been doing circuit design professionally for years (me, I'm 50 years after graduation from M.I.T.)

You have your head firmly up your butt, yet claim you know what you are doing.

So... Don't go away mad... just go away. ...Jim Thompson

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K

krw 13 years ago

The projection is all yours. Like all lefties, you need to be acquainted with a mirror. Clearly you don't want to learn. It's surprising people have helped you this far. You're not worth it.

Like all lefties, you're a liar. It's a requirement.

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Signal amplifier works

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