David Living Perlmutter

US Patent:

41568605, May 29, 1979

Filed:

Aug 3, 1977

Appl. No.:

5/821421

Inventors:

Ali E. Atia - Gaithersburg MD
David Perlmutter - Gaithersburg MD
Paul R. Schrantz - Gaithersburg MD

Assignee:

Communications Satellite Corporation - Washington DC

International Classification:

H01P 706
H01P 130
H01P 116

US Classification:

333229

Abstract:

A device for a resonant microwave cavity which includes a tuning plunger assembly to make the resonant frequency less temperature sensitive. The frequency response of a cavity filter, determined by its resonant frequency, primarily depends on the dimensions of the filter cavity. Since cavity dimensions will vary with changes in ambient temperature, some form of compensation is necessary to stabilize the frequency response. The tuning plunger assembly is comprised of a sandwich of materials having substantially different coefficients of expansion. One of the materials, a potting compound with a high coefficient of thermal expansion, acts as an operator to vary the configuration of the plunger assembly in order to maintain the resonant frequency of the cavity substantially fixed.

US Patent:

39367444, Feb 3, 1976

Filed:

Apr 30, 1974

Appl. No.:

5/465600

Inventors:

David Perlmutter - Island Park NY

International Classification:

G01R 1512
G01R 3102

US Classification:

324158R

Abstract:

A tester for a solid state voltage regulator includes two parallel branches available for interconnection to the two output contacts of the voltage regulator. The two branches both interconnect to the high voltage side of a battery. One of the branches includes a resistor in parallel combination with an indicator bulb. One of the branches includes a normally open switch. For use with automobile alternators having a built-in regulator, the tester can be connected directly to the regulator and test both the regulator and the alternator. When the regulator is independent of the alternator, it can be tested by itself by using actual rotor current available from an alternator used in conjunction with the tester. The on/off condition of the indicator bulb, when the switch and various contact terminals are interconnected, provides an indication of the effective operation of the regulator. A volt meter can be included integrally with the tester to provide output readings of the regulator.