Robert A Christopher
Engineers in Boulder, CO

License number
Colorado 20295
Issued Date
Jan 26, 1983
Renew Date
Dec 31, 1985
Expiration Date
Dec 31, 1985
Type
Professional Engineer
Address
Address
427 Mech Engr Dept Box 427 U Of Colorado DEPT BOX, Boulder, CO 80309
LicenseFiles verified this license of Dec 9, 2016 at the Colorado - Department of Regulatory Agencies.

Professional information

Robert Christopher Photo 1

Reel Motor Preamplifier

US Patent:
4177433, Dec 4, 1979
Filed:
Nov 20, 1978
Appl. No.:
5/962278
Inventors:
Robert J. Christopher - Boulder CO
Robert L. Schaaf - Tucson AZ
Assignee:
International Business Machines Corporation - Armonk NY
International Classification:
H03F 320, H03F 368
US Classification:
330265
Abstract:
A high voltage/high current circuitry includes a push-pull voltage amplification stage connected in tandem with a parallel connected push-pull current amplification stage. For the voltage amplification stage a pair of bipolar operational amplifiers are connected in parallel and operate in a push-pull manner. A pair of switching means are positioned at the output of each of the bipolar operational amplifiers while the outputs of the amplifiers are connected to the inputs through a current gain regulating means, an isolation means and a voltage divider means.

Engineers licenses in Colorado