Accession Number : ADD007075

Title :   Direct Reading Capacitance Meter.

Descriptive Note : Patent Application,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Shaw,Clifford O

Report Date : 06 Mar 1980

Pagination or Media Count : 17

Abstract : This invention relates to an apparatus for measuring capacitance, especially large capacitance. The resulting measurement is displayed on a meter calibrated in capacitance. One method of determining the capacitance of a large, unknown capacitor is to charge it to a predetermined DC voltage, then discharge it through a known resistor and an SCR while observing the discharge wave form on an oscilloscope. Another method is to insert the unknown capacitor in a bridge circuit in which fixed capacitors and, in some cases, other circuit elements are provided. The present invention obviates the above mentioned prior art by providing a direct reading capacitance meter for measuring a wide range of capacitances. The invention has circuits for a voltage comparator and logic trigger, a flip-flop multi-vibrator, and a ramp generator. The output voltage of the ramp generator is determined by the duration interval of the input pulse, and produces a reading on a meter which is calibrated in three ranges of capacitance to provide the user with a direct reading capacitance meter.

Descriptors :   *Patent applications, *Electrical measurement, Capacitance, Waveform generators

Subject Categories : Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE