A Logarithmic Voltage Quantizer

This paper describes an analog to digital converter which converts voltage into a number which is proportional to the logarithm of the voltage. The device is completely automatic. It can handle input data at the rate of 10,000 voltage samples per second. The accuracy of conversion or quantization is determined by the designer´s selection of the circuit parameters. The Radiation Laboratory quantizer has a maximum quantization error of 5 per cent. Samples of duration greater than .5 microsecond can be quantized.