Ultra High Gain Preamp

174

02:30:39

I suppose this is two stage, but it still has a sensitivity of 1-2uV! That gives each stage an average gain of 1000. Actually, I’m not sure that’s the true average, but rather that because of the design, when these two are coupled it gives a higher overall gain.

published 8 years ago

hurz

8 years ago

Jason you know, build it test it and see what it does in reality.

jason9

8 years ago

I’m just a 13 year old. I don’t have access to the money needed to buy the components.

jason9

8 years ago

If you could bias it correctly in real life and it actually had the high amplification shown here, then it would serve as a good RNG.

hurz

8 years ago

Then wait till you have more money.

jason9

8 years ago

You mean, like, 5 years? That’s more than the age of this app! (This app has been around for about 3 years, right?)

hurz

8 years ago

Print it or draw it on paper and wait 5 years till you got the money as UPS slave OR invest some dollars in your future as engineer. Its up to you.

tonyinselby

8 years ago

You can buy components very cheaply from sellers such as Geek or Alibaba. 300 general purpose transistors for $8 or a few hundred assorted resistors for $5 or so are typical. Sure, they're often cheap Chinese knockoffs, but you're not repairing the ISS, after all. Just be prepared to wait 6-8 weeks for delivery.

jason9

8 years ago

6-8 weeks? I didn’t even know deliveries could take that long. I suppose they can if they’re Chinese since they have to literally cross the worlds largest ocean. Also, I was trying to get my family to buy some components on Amazon for the first two chapters of Make: Electronics, and they ended up having to buy a $75 kit because they were having trouble finding all the components with the right values and the cost was piling up anyway. They agreed not to get anything more because of the cost even though chapters 3 and 4 of the book were the only ones of real interest.

tonyinselby

8 years ago

The delivery time is the price you pay for, say, fifty 555 timers for under six dollars.

thebugger

8 years ago

Noise is your biggest enemy. If you don't have any means to separate the signal from the noise you'll probably end up with either an oscillator with these gain levels or a white noise amplifier. At 1uV different atmospheric and thermal noises become prevalent and worsen the SNR ratio (a lot).

jason9

8 years ago

@thebugger, this could be a true random number generator. Not a pseudo random number generator, but an actual, true, 100% unpredictable RNG. With 1uV of sensitivity, that’s the only real application that this could be used for. Hmmm, I suppose that with that much sensitivity, the power supply would have to be ultra stable so that any signal from it would also have to be from things like thermal noise. Maybe if this was done on a breadboard, that would pick up a bunch of noise too further increasing the effectiveness as an RNG.

hurz

8 years ago

Years ago, buggzy also presented such a circuit. I think it was even a 3 stage bjt amplifier. And we told him (secuture and I) its probably more a noise generator or even better a radio receiver. He answered we are talking bullshit. He is using shielding and ultra low noise transistors bc549 bla bla bla. Two days later he presented the very same circuit with a different headline and called his amplifier from now on "am radio receiver". Oh boy time goes by....

thebugger

8 years ago

Random number generators can be made much simpler with only one or two transistors. There's a circuit EC can't simulate where the CE junction of the transistor is reversed and the base - unconnected. When the appropriate voltage is added to the emitter terminal (through a resistor) the circuit starts making white noise, which is as close to random as you'd get. http://www.experimentalistsanonymous.com/ve3wwg/lib/exe/fetch.php?cache=&media=white_noise_stage.png

thebugger

8 years ago

And there's also the chua oscillator.

hurz

8 years ago

Its the EB junction and the Collector keeps open. Apply almost any voltage (not a appropiate one, what ever this is) to a diode in reverse will cause noise. BTW, any diode junction (PN junction) does cause noise in forward and in reverse. From this reason noise-reduced amplifier do have as less as possible transistors as component. Watch one of your amplifier called "noiseless" and count the number of transistors. LOL

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