Looking for noise generator circuit

[Wowee]

I want to generate white noise in my design.Could somebody provide a cheap circuit.Thanks

 

[flatulent]

two methods

Here are two methods. If you want an approximation, a maximum length feedback shift register sequence will work.

An electronic method is to reverse bias a BJT base emitter junction with a series resistor to limit the current once it breaks over (Zener action). Follow this with an amplifier to get the level to what you want.

If you want extremely wide band noise there are special tubes you can buy.

 

[se7en]

there is specific test equipment on the market

 

[THE BORG]

you can make one from a 5v or 6 v miniture light bulb

just blow the filliment with 12 v paint it with conductive paint paint in a small conductor
and use this too provide a field signal
any field signal is white noise connected too a bjt

some instuments use this approch

as above
but this isnt a special one but its a cheep one

 

[RegUser_2]

Pass a current through a zener diode close to the zener threshold current then AC couple the zener voltage.