Please can anybody give me a method to convert a +12V supply to a -12V supply without the use of opamps. We do not have a -ve power supply on board and want to avoid the use of a -ve supply battery. Since opamps requires a -ve supply, it is ruled out.
Please help me out.

 

hi

here's a circuit to derive a negative output from a positive rail. however this has certain limitations like the current output. with light loads this can suffice. but if you need as high as 500ma. you can use TL497A as polarity inverter, although it was originally designed for downward or upward transformation application, this device is from Texas Instrument, check on the datasheet.

 

Originally posted by mozikluv@Feb 24 2005, 07:26 AM
hi

here's a circuit to derive a negative output from a positive rail. however this has certain limitations like the current output. with light loads this can suffice. but if you need as high as 500ma. you can use TL497A as polarity inverter, although it was originally designed for downward or upward transformation application, this device is from Texas Instrument, check on the datasheet.

[post=5572]Quoted post[/post]​

Thanks very much. I'll revert to you as soon as I try it.

 

Originally posted by mozikluv@Feb 24 2005, 07:26 AM
hi

here's a circuit to derive a negative output from a positive rail. however this has certain limitations like the current output. with light loads this can suffice. but if you need as high as 500ma. you can use TL497A as polarity inverter, although it was originally designed for downward or upward transformation application, this device is from Texas Instrument, check on the datasheet.

[post=5572]Quoted post[/post]​

Tried TL497A. Works great. Thank you.

 

hi shaun,

am glad that device help solve your problem