William H Thatcher

Author:

William Thatcher

ISBN #:

0668023783

US Patent:

6209338, Apr 3, 2001

Filed:

Jul 2, 1999

Appl. No.:

9/347128

Inventors:

William Bradford Thatcher - Atlanta GA

International Classification:

F25B 4500

US Classification:

62292

Abstract:

A refrigerant storage reservoir, connected by valves to the high and low pressure lines of a refrigeration system, and controlled by a microprocessor based system that monitors temperatures and pressures, provides a means of regulating the overall amount of refrigerant charge in a heating or cooling system to optimize economy or performance during operation. Reference temperature and pressure data profiles, permanently stored in memory, are compared with actual data collected while the refrigeration system is operating. If a reduction of refrigerant charge is indicated, a valve on the high pressure side of the refrigeration system is opened to allow excess refrigerant to flow into the storage reservoir. If an increase in refrigerant charge is indicated, a valve on the low pressure side of the refrigeration system is opened to allow refrigerant to flow from the reservoir into the operating loop of the refrigeration system. In accordance with an alternative embodiment, the microprocessor based system stores temperature and pressure data collected during refrigeration system operation in a local Non-Volatile-Memory (NVM) and uses this self collected data to develop custom temperature and pressure data profiles that reflect the actual installed refrigeration system.

US Patent:

53414241, Aug 23, 1994

Filed:

Sep 2, 1993

Appl. No.:

8/115358

Inventors:

William B. Thatcher - Atlanta GA
Mark E. Schutte - Sugar Hill GA

Assignee:

Scientific-Atlanta, Inc. - Norcross GA

International Classification:

H04K 102

US Classification:

380 7

Abstract:

An off-premises method and apparatus for the interdiction of unauthorized channels of a broadband cable television signal includes common circuitry for adjusting the amplitude and equalization levels of the broadband CATV signals and one or more subscriber modules for generating jamming signals of different frequencies which are used to interdict one or more unauthorized channels. Each subscriber module is associated with a subscriber and is programmable and addressable to adjust the jamming parameters of that subscriber independently of other subscribers. Each subscriber module circuit comprises a plurality of latches, each of which is associated with one of a plurality of digital to analog converters. Each of the digital to analog converters drives one or more frequency agile oscillators with its analog output to generate the jamming signals. The subscriber module is based on a sequential state machine which loads frequency control words corresponding to the jammed channels from a frequency control memory into each latch on a cyclic basis.

US Patent:

50581600, Oct 15, 1991

Filed:

Oct 1, 1990

Appl. No.:

7/593329

Inventors:

Robert O. Banker - Cumming GA
Randolph Schaubs - Stone Mountain GA
Michael Harney - Atlanta GA
Jay C. McMullan - Doraville GA
Anthony Wasilewski - Lawrenceville GA
Gregory S. Durden - Jonesboro GA
Rdy T. Haman - Duluth GA
David Naddor - Doraville GA
William B. Thatcher - Alpharetta GA

Assignee:

Scientific-Atlanta, Inc. - Atlanta GA

International Classification:

H04N 7167

US Classification:

380 20

Abstract:

The present invention discloses a method and apparatus for providing a cable TV system with the ability to issue information from a system manager, determine whether the information is intended for a set top designed to receive out-of-band information or in-band information, send the information to the appropriate circuitry. Reformatting of some information is necessary and is performed by a format translator. For in-band information, information may be sent over one or more of a plurality of data streams. Certain types of information are sent over one or more data streams based on the type of information and characteristics of the data streams. It is further disclosed that for efficiency, similar information intended for several addresses is grouped together in a database manager so that the information may be sent to plural addresses at one time. Scramblers are employed with the capability of inserting data onto nonscrambled channels.

US Patent:

53596013, Oct 25, 1994

Filed:

Mar 8, 1993

Appl. No.:

8/027782

Inventors:

Anthony J. Wasilewski - Alpharetta GA
William B. Thatcher - Atlanta GA

Assignee:

Scientific-Atlanta, Inc. - Atlanta GA

International Classification:

H04H 106

US Classification:

370 73

Abstract:

An apparatus providing a dynamic virtual service capability in a multi-service communications system is claimed. A dynamic virtual service comprises an associated group of basic services wherein only one of the basic services in the group is active at any time. Basic services comprise a number of service components which are transmitted to the apparatus on one or more of a plurality of different frequency channels. The apparatus comprises a service selection switch for selecting either one of the basic services directly or one of the dynamic virtual services. A dynamic virtual service map is provided that defines for each dynamic virtual service, on a time-varying basis, the currently active one of the group of basic services that comprise that dynamic virtual service. Means responsive to the service selection switch and to the dynamic virtual service map are provided for automatically selecting the currently active basic service of a subscriber selected dynamic virtual service. Finally, the apparatus provides means for receiving and accessing the service components of a selected basic service from the frequency channel carrying those components.

US Patent:

59370670, Aug 10, 1999

Filed:

Nov 12, 1996

Appl. No.:

8/745483

Inventors:

William Bradford Thatcher - Atlanta GA
Anthony J. Wasilewski - Alpharetta GA

Assignee:

Scientific-Atlanta, Inc. - Norcross GA

International Classification:

H04L 908
H04L 932
H04N 7167

US Classification:

380 21

Abstract:

An encryption control system to process an input transport data stream into an output transport data stream includes an input demultiplexer, a first secure microprocessor, a second secure microprocessor and an output multiplexer. The input transport data stream includes first entitlement managment message data. The input demultiplexer culls the first entitlement managment message data from the input transport data stream, the first entitlement management message data including an encrypted multi-session key. The first secure microprocessor processes the first entitlement management message data to recover the multi-session key by decrypting the encrypted multi-session key using a first algorithm. The second secure microprocessor re-encrypts the multi-session key using a second algorithm and formats second entitlement management message data based on the first entitlement management message data with the re-encrypted multi-session key substituted for the encrypted multi-session key. The output multiplexer provides the output transport data stream based on the input transport data stream with the second entitlement management message data substituted for the first entitlement management message data.

US Patent:

52854973, Feb 8, 1994

Filed:

Apr 1, 1993

Appl. No.:

8/041727

Inventors:

William B. Thatcher - Atlanta GA

Assignee:

Scientific Atlanta - Norcross GA

International Classification:

H04L 900

US Classification:

380 49

Abstract:

Methods and apparatus for encoding compressed data streams efficiently, and methods and apparatus for decoding the encrypted data streams efficiently and inexpensively, are disclosed. In an encoder 10', an incoming data stream is fed to a Huffman coding block 10 that performs data compression. The output codewords of the Huffman coding block are fed to a forward error correction block 30, the output of which is a series of data blocks and associated parity data. The data blocks are fed to an error insertion block 32, which inserts a one-bit error in each data block. The parity data is fed to a first encryption block 34 that produces encrypted parity data. The output of the error insertion block 32, the encrypted parity data, and a synchronization word output by a sync generator 50 are fed to a multiplexer 48. A seed generator block 36 generates random numbers for use by the first encryption block 34 as seeds for encrypting the parity data. A multisession key register 40 stores a multisession key employed as a seed in a second encryption block 38 to encrypt the random number seed.

US Patent:

54636892, Oct 31, 1995

Filed:

Sep 2, 1993

Appl. No.:

8/115357

Inventors:

Mark E. Schutte - Sugar Hill GA
William B. Thatcher - Atlanta GA
Lamar E. West - Maysville GA

Assignee:

Scientific-Atlanta - Norcross GA

International Classification:

H04K 100

US Classification:

380 7

Abstract:

An off-premises method and apparatus for the interdiction of unauthorized channels of a broadband cable television signal includes common circuitry for adjusting the amplitude and equalization levels of the broadband CATV signals and one or more subscriber modules for generating jamming signals of different frequencies which are used to interdict one or more unauthorized channels. Each subscriber module is associated with a subscriber and is programmable and addressable to adjust the jamming parameters of that subscriber independently of other subscribers. Each subscriber module circuit comprises a plurality of latches, each of which is associated with one of a plurality of digital to analog converters. Each of the digital to analog converters drives one or more frequency agile oscillators with its analog output to generate the jamming signals. The subscriber module is based on a sequential state machine which loads frequency control words corresponding to the jammed channels from a frequency control memory into each latch on a cyclic basis.