A General Purpose Electronic Multiplier

An electronic multiplier has been developed which appears to bring to the art of analog computation some new and highly desirable features. This device has a dynamic range of 500 to 1 for an absolute accuracy of about 1%. Either or both analog voltages may vary arbitrarily with time, and may contain components in the frequency range from 0 to 150 sinusoidal cycles, products as low as 5mv-rms can be detected. The sensitivity of the instrument is denoted by the over-all attenuation of 3. The drift of the unit is less than 20 mv at the output over an 8hr period from a cold start. The above characteristics have been achieved by the application of what is known as the Differance in Magnitude Method. There are no balancing adjustments other than a dc level control located on the front panel. An attenuator is also provided for setting the input voltage to the proper level so as to provide maximum output voltage without overloading the instrument.