White noise generator

if your small speaker has an impedance of 50 or more ohms and ypu don't need it very loud it could work.

an LM386 is a better choice for a small 4 or 8 ohm speaker.

Bye. Jasen

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Thanks. Would a 741op-amp drive a small speaker? If so would two or three of these in series do the job? Would you bias the + input to half the single supply voltage (12 volts) in each case and use 470pf capacitors between the zener diode and the first stage, between each stage and between the last stage and the speaker?

Roger

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Noise across the audio spectrum of a small speaker. The speaker will be some metres away from the signal generating part of the device. The noise level must be controllable nearly upto the limit of the speaker.

I have just about come around to the idea of a 12 volt Zener diode driving two LM741s followed by a LM368N to drive the speaker. The op-amps would have a 12 volt unbalanced supply with the + inputs of the LM741s biassed to

6 volts. The parts are all available and cheap. I have the speaker. Would this work in your view? R

Pink noise, actually.

John

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Thanks. Should I use a lower voltage zener diode then? The extra noise will not matter.

Roger

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Connect the + input directly to ground and feed the signal through a (?)100 nF capacitor and a resistor into the - input?

Roger

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Record one of Howard Deans' speeches/rants. That's some pretty good white noise.

LOL, yeah, you're right. Maybe even a bit red.

it is. "alt.binaries.schematics.electronics". (note to self:"Avoid IHUG") fwiw Clear and compass/freenet carry it. compass/freenet's server is half-arsed. AFAIK there's me and maybe two other people who actually use it.

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Bye.
   Jasen

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(?)100

My ISP does not provide a.b.s.e which I presume is a binary ng covering electronics. I would be very grateful if you could manage to email me the drawing as a .jpg file.

Roger

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That fellow, whoever he may be, is of so little interest to anyone in this country (NZ) that his rants are unavailable and unrecorded.

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