Hi again everybody. I've been searching for answers on providing a negative voltage from a single source or other workarounds. I have breadboarded an op-amp sine wave oscillator using an LM741 from a schematic in one of Forrest Mims III's books but it's clipping of the lower half of the wave because it can't swing below zero volts.

So my question is how can I reference the voltage so the wave form doesn't have to swing below zero volts thus using a single battery supply? Otherwise, can I create (easily) a negative voltage source with a single battery? Is it possible?


Attached is the schematic of the circuit. Thanks in advance.
Doc

 

One way to solve the problem is to take another 741 opamp and connect it up as a voltage-follower and then use two equal valued resistors around 10Kohms to set the input to the voltage follower to Vcc /2. Take the output of the voltage follower and use it in place of the ground reference in your circuit.

hgmjr

 

Thanks - I think I understand. Before I ask you to elaborate, I'll work on it first. That helps me learn.

 

Here is an example of a voltage follower presented in the AAC ebook section of this forum.

hgmjr

 

YOu can use a rail splitter like the TLE2426 from Texas Instruments. In fact, here is a page that discusses the circuit in question along with other ideas:

http://tangentsoft.net/elec/vgrounds.html