Probably a very elementary question, but I've never felt like I had a solid grasp of this.
In audio and analog circuits, I've sometimes seen the use of dual rail power supplies such as +/- 15V. These have been to power op-amps and similar circuits.
If I understand correctly, the positive rail flows current from the source rail to GND. and the positive rail flows current from GND to the negative rail. Is that correct?
My two questions are the following:
1) Why would you need a negative voltage rail? What would lead someone to engineer one into a design?
2) How does a dual rail power supply work? Do you make a 30V supply and tie a rail halfway between the 30V and 0V to GND (thus giving 15V above GND and -15V below GND)?
Thanks!
In audio and analog circuits, I've sometimes seen the use of dual rail power supplies such as +/- 15V. These have been to power op-amps and similar circuits.
If I understand correctly, the positive rail flows current from the source rail to GND. and the positive rail flows current from GND to the negative rail. Is that correct?
My two questions are the following:
1) Why would you need a negative voltage rail? What would lead someone to engineer one into a design?
2) How does a dual rail power supply work? Do you make a 30V supply and tie a rail halfway between the 30V and 0V to GND (thus giving 15V above GND and -15V below GND)?
Thanks!