Hello I am new here, I need you regarding a montage that I have to make. I have an input PWM signal which varies from 0 to + 15V. I have to find an electronic assembly in order to obtain at output a PWM signal varying from 0 to -10V. I have a -10V power supply. However, I have the constraint of only use bipolar transistors. Did you know a montage allowing me to do this? thanks in advance

 

How much current do you need from the output PWM?
What frequency is the PWM?

 

I have an input PWM signal which varies from 0 to + 15V. I have to find an electronic assembly in order to obtain at output a PWM signal varying from 0 to -10V.

Your post is ambiguous.
Are you referring to the variation in the PWM duty-cycle or the variation in its averaged DC voltage?

For the former you could use a PNP transistor.
For the latter, you could use an op amp.

 

Most power supplies do not work near 0V. Most will not work below 2.5V.

Please state input voltage range. (+10 or -10?)
Output voltage range? 0 to -10V
Output current?

 

Most power supplies do not work near 0V

I think the -10V supply is just for power, not that he wants to control it.

 

Hello I am new here, I need you regarding a montage that I have to make. I have an input PWM signal which varies from 0 to + 15V. I have to find an electronic assembly in order to obtain at output a PWM signal varying from 0 to -10V. I have a -10V power supply. However, I have the constraint of only use bipolar transistors. Did you know a montage allowing me to do this? thanks in advance

Does "montage = assembly", and is that the same thing as a circuit?

 

Thanks a lot for your answers and sorry for my mistakes in english,
I will try to be more precise, I am currently looking for an electronic function allowing me to invert a square wave. I do not have any precision on my input frequency nor on my necessary output current as well as on my input / output impedances. The only thing I know is that it is a square wave varying from 0 to + 15V. Thus, I must obtain a square signal at the output varying from 0 to -10V (level of my power supply) or a little below. So naturally I would have gone for an inverting amplifier but unfortunately my condition is to only use bipolar and mosfet transistors. I have a voltage of -10V as a power supply to help me. Do you think this function is achievable with only negative supply voltage? If yes, do you know a circuit to do this? Thank you very much for your help

Recapitulation :
Input voltage range : 0 to +15V
Signal shape: square
Input frequency : ?
Input impedance : ?

Ouput voltage range : 0 to -10V
Signal shape: square + no dephasage between entry and exit
Output frequency : same frequency as input
Output impedance : ?

 

When the input is 15V should the output be 0V or -10V?

 

Like this?

 

Like this?

View attachment 252899

Exactly, thank you very much Irving ! I still need to learn a lot of things.

 

Exactly, thank you very much Irving ! I still need to learn a lot of things.

You're welcome.

It may need tuning for your specifics, eg frequency, driving source, output load, etc. but feel free to shout out when you know more.

 

Below is a slightly simpler alternate design using a PNP transistor in a grounded-base configuration:

 

Below is a slightly simpler alternate design using a PNP transistor in a grounded-base configuration:

View attachment 252915

Nice, but it does a phase inversion that the TS didn't want. He wanted +15v -> -10v, yours does +15v -> 0v, 0v -> -10v, though it might be OK if his eventual need is edge driven.

 

Cool. Two ways of doing it to one problem. How would you do it with a LM393?

 

How would you do it with a LM393?

Why would you want to use an LM393 when you can do it with one transistor?