a circuit that converts positive voltage to negative voltage

[wien]

How can I make a circuit that outputs a negative voltage of -12V if I input a positive voltage?

I don't have a part called LM2575-12BT here, can you recommend it as one of the parts on mouser.kr ?

 

[aliarifat794]

L7912CV is a good option. However, I am not sure if that is available at mouser.kr or not.​

 

[dick_freebird]

Inverting charge pump or negative boost converter.

 

[KlausST]

Hi,

a power supply voltage? -> maybe a switched capacitor inverter
or a signal voltage? --> maybe an inverting OPAMP circuit

in a way that 12V becomes -12V?

and 13V becomes -13V?
or 13v stil become -12V?

What current?
What accuracy?
What efficiency?
Is noise an issue? If yes, specify the max.

Klaus

 

[betwixt]

... and L7912CV is most definitely NOT a good option!
Its a 12V negative regulator, not a charge inverter.

Brian.

 

[dick_freebird]

I've seen but never used those parts made to look like 7812 but with switcher guts in the classic TO-220 form. Seems to me that an inverting version of those could be made same-same. Whether the vendor or the market ever saw traction, no idea.

 

[Easy peasy]

The full data sheet covers this quite well - how to organise the feedback etc - also the need for a delayed start - as the device will otherwise draw a lot of current from the source.

 

[crutschow]

How can I make a circuit that outputs a negative voltage of -12V if I input a positive voltage?

How much -12V current do you need?
What's the load?