Supply Polarity Splitter

179

02:56:43

When you work with op amps and signals a lot you'll find yourself in need of a negative supply rail. Now if you're like me and don't have an expensive bench top power supply, or if your circuit needs to be powered with one single battery. Then this little circuit comes in real handy.

It basically splits the source voltage in half and uses one for the positive rail and the other for the negative rail. It also creates a virtual ground point, which is ofcourse needed.

Leds are there for demonstration purposes.

published 10 years ago

hurz

10 years ago

It does work only for symmetric load of both rails. Change the current at upper led by increase the 470 ohm. This will cause a voltage drop at lower led! It only works if the drawn current is 10 times lower then the voltage divider current. Or both rails are loaded symmetrical! In this case here, only ~300uA unsymmetrical load is possible, which is a very weak symmetric supply.

kaivanveldhoven

10 years ago

Thanks for the comment hurz. I have tested this irl with a 741 op amp in just a non inverting configuration, amplifying a sine wave. This did work for me. So I guess an op amp is pretty symmetrical then..

hurz

10 years ago

The caps help to filter the unsymmetric load.

kaivanveldhoven

10 years ago

Ah, I get it. Thanks

add comment in editor

EveryCircuit is an easy to use, highly interactive circuit simulator and schematic capture tool. Real-time circuit simulation, interactivity, and dynamic visualization make it a must have application for professionals and academia. EveryCircuit user community has collaboratively created the largest searchable library of circuit designs. EveryCircuit app runs online in popular browsers and on mobile phones and tablets, enabling you to capture design ideas and learn electronics on the go.