Hey all,
I'm experimenting with a simple white noise generator at the moment. To be exact this one:
https://synthnerd.wordpress.com/2020/03 ... generator/
It's seems that I'm not really able to really spin my head around the basics of how this ciruit works, so maybe you can give me a push in the right direction as not even MFOS gave me clearification as it normally does![:)]( "smile")
I understand the buffer/amplification part of the circuit but I don't really get the noise creation part.
As I understand we reverse the NPN transistor to send voltag through the ermitter to the base to create noise.
1.) To get the the transistor to produce noise, we have to supply a voltage which is higher then the breakdown voltage of the base-ermitter connection of the transistor. Same could be achieved with a Zener diode. Is that correct?
2.) Because of tolerances, the needed breakdown voltage can be higher than stated in the datasheet. So the higher the supply voltag the more likely it is to get the transistor into breakdown, correct?
3.) Why do "newer" "better" transistors produce less noise? Is it because the concrete needed breakdown voltage is higher? Shouldn't all transistors produce a kind of noise which could be amplified?
4.) What does the resistor R2 do? As I understand it regulates the current to the transistor? How does this affect the noise output?
I can get the circuit to work most of the time, but I'm not really understanding what I'm looking for with my transistors or with the resistor.
As I want to build more than one of the generators, it would be great to know what I'm looking for to get consistent results.
Thx!
I'm experimenting with a simple white noise generator at the moment. To be exact this one:
It's seems that I'm not really able to really spin my head around the basics of how this ciruit works, so maybe you can give me a push in the right direction as not even MFOS gave me clearification as it normally does
I understand the buffer/amplification part of the circuit but I don't really get the noise creation part.
As I understand we reverse the NPN transistor to send voltag through the ermitter to the base to create noise.
1.) To get the the transistor to produce noise, we have to supply a voltage which is higher then the breakdown voltage of the base-ermitter connection of the transistor. Same could be achieved with a Zener diode. Is that correct?
2.) Because of tolerances, the needed breakdown voltage can be higher than stated in the datasheet. So the higher the supply voltag the more likely it is to get the transistor into breakdown, correct?
3.) Why do "newer" "better" transistors produce less noise? Is it because the concrete needed breakdown voltage is higher? Shouldn't all transistors produce a kind of noise which could be amplified?
4.) What does the resistor R2 do? As I understand it regulates the current to the transistor? How does this affect the noise output?
I can get the circuit to work most of the time, but I'm not really understanding what I'm looking for with my transistors or with the resistor.
As I want to build more than one of the generators, it would be great to know what I'm looking for to get consistent results.
Thx!
Statistics: Posted by KeenVox — Mon Mar 03, 2025 5:40 pm — Replies 1 — Views 66