positive, neg. volt

[irishape]

I understand how to use pos. neg v but how to use both in same circuit eludes me because I am in prelearning mode. Maybe this attachment will allow you to see what I mean. Thank you. IA

 

[cowboybob]

Are you referring to the + and - signs on the op-amps?

If so, they indicate: If a - sign, the inverting input and is a + sign, the non-inverting input to the op-amp.

 

[LukeeeeBennett]

If you have 2 batteries for examples, you can "reference ground" between them then relative to that ground 1 will be -V and the other +V.

View attachment 60232

 

[Gobbledok]

Hi Irishape,

they are called 'bipolar power supply' and here is the general basic schematic:
View attachment 60233

 

[irishape]

positive, neg volt

Hi Gobbledok, are you saying to use a transformer with center tap to ground and picking up + and - from rectifier? This circuit is for a noise maker which I would like to use that source type rather than batteries. Also would that common ground be used on the whole circuit as Luke shows with the batteries?

 

[Gobbledok]

Hi irishape,

Yes that's right. The centre-tap is then your ground-reference for the whole circuit and you connect it to other grounds which may exist on the same circuit.

Yes your+/- voltage come from the bridge rectifier. Take note that the bottom regulator is a 7915 (instead of 7815) which is a negative regulator.

 

[irishape]

Hi irishape,

Yes that's right. The centre-tap is then your ground-reference for the whole circuit and you connect it to other grounds which may exist on the same circuit.

Yes your+/- voltage come from the bridge rectifier. Take note that the bottom regulator is a 7915 (instead of 7815) which is a negative regulator.

Thank you very much, you are going to have me so smart that the smoke will clear out in my work area enough I can see what I am doing. Cheers

 

[Gobbledok]

Haha the good ol' magic smoke. Don't worry, there's plenty left where that came from.