The C&C T-CAV ac signal converters convert low level voltage into a load independent dc current or voltage signal capable of driving a number of independent instruments. Power for the unit is derived from an auxiliary supply. The output signal is calibrated to rms, based on an arithmetic mean measurement of the rectified input signal, and hence the transducer should be used with undistorted sine waveforms (<1% distortion). Input, output and auxiliary supply are all galvanically isolated from each other allowing the separation of signal circuits.