How do I increase circuit voltage

[radb]

Hi,

I'm working on an interface between a radio and a sensor, but am having trouble getting the sensor to detect the voltage being output by the radio. The idea is that when the radio receives a signal, a control line in the radio drops to earth. I wanted to wire this control line to the sensor to wake it up when low, but am having trouble.

The problem is the potential difference between the control line and earth is only 5mV. I would like to boost this up to 5 or 12V for the sensor to activate. I've tried using a PNP transistor circuit, but with my limited electronic knowledge, I think the transistor is detecting the 5mV as a ground.

Any help would be great.

Thanks in advance.

 

[kspalla]

Use simple op amp with gain of 1000 to get 5V from 5mv input.

 

[radb]

Thanks kspalla,

I initially thought an OpAmp would be the go, but got some advice from someone to use a transistor. :|

Back to the drawing board!