Hi, I want to reduce DC voltage with -15 volt (bias voltage). For example, I have sine input wave with 0/30 volt DC amplitude and I want to convert to sine wave with -15/+15 volts amplitude, what the circuit or component used for this work? thanks.

 

... thinking that a center tapped transformer could accomplish this ...
The output ground terminal would be the center tap on the secondary side.
It would necessarily have a 1:1 winding ratio. What is the load requirement, in watts? What will it be used for?
... see this reference:
https://en.m.wikipedia.org/wiki/Center_tap

There is frequently a safety hazard associated with these transformers, since one side will likely be directly connected to a dangerous AC voltage source. It may be that a better choice would be what is called an isolation transformer, which insulates the secondary side from the primary side, and could potentially prevent a serious injury.

 

Use a capacitor to block the DC component, it will center the signal on 0V.

 

... thinking that a center tapped transformer could accomplish this ...
The output ground terminal would be the center tap on the secondary side.
It would necessarily have a 1:1 winding ratio. What is the load requirement, in watts? What will it be used for?
... see this reference:
https://en.m.wikipedia.org/wiki/Center_tap

There is frequently a safety hazard associated with these transformers since one side will likely be directly connected to a dangerous AC voltage source. It may be that a better choice would be what is called an isolation transformer, which insulates the secondary side from the primary side, and could potentially prevent a serious injury.

The load is very low. About 20 watts. For use in piezoelectric.

 

Use a capacitor to block the DC component, it will center the signal on 0V.

@mohammadreza emadi It is hard for me to be sure what you are asking for, but if it is what it sounds like, this advice it spot on. A simple DC blocking capacitor is precisely the way to do interstage AC coupling when there is a bias voltage that needs to be isolated.

 

Use a capacitor to block the DC component, it will center the signal on 0V.

please send more information. thanks a lot.

 

... not certain that I understand the application completely. ... Would appreciate a picture of the waveform or possibly a circuit diagram. ... There seems to be some kind of minimum number of forum posts before attachment privileges are acquired. You are almost there I think, ... just a few more posts.

 

This is what Sensacell was referring to -

Regards, Dana.

 

can I use IC op-amp 741 for this work? use for piezoelectric.

 

Why not use the capacitor solution from #8? Other requirements for this?

 

Why not use the capacitor solution from #8? Other requirements for this?

Hi, if i use the capacitor in this circuit, the voltage drop in exist in work and it's not good. can I use op-amp 741?

 

Hi, if i use the capacitor in this circuit, the voltage drop in exist in work and it's not good. can I use op-amp 741?

Not. The output power of the amplifier is milliwatts. 1mW = 0.001W