Converting negative analog voltage to positive

[zhiling0229]

Hey guys,

I need to find out how to convert an analog voltage that is negative to a positive voltage. For example a -1.87V to 1.87V.

Thanks guys. Really appreaciate it.

 

[audioguru2]

An inverting opamp with the input resistor the same value as the negative feedback resistor, and positive and negative supplies.

 

[zhiling0229]

Thanks Audio guru your a great help  ;D,

Was wondering is there an alternative method instead of using another OP-AMP.

 

[audioguru2]

Was wondering is there an alternative method instead of using another OP-AMP.

Opamps are inexpensive, small and work very well.
A single transistor has a 0.65V offset voltage that would need adjustment to reduce, and it changes with temperature change.
You could use a two-transistor differential amplifier as an inverter. It is the input stage of an opamp.