Peter C Skerlos

US Patent:

39639967, Jun 15, 1976

Filed:

Sep 5, 1974

Appl. No.:

5/503220

Inventors:

Peter Constantine Skerlos - Arlington Heights IL

Assignee:

Zenith Radio Corporation - Chicago IL

International Classification:

H03B 512

US Classification:

331117R

Abstract:

An oscillation system includes a pair of differentially connected oscillator transistors having a resonant tank circuit connected between collector electrodes and a current source transistor connecting both emitter electrodes to ground. The collectors and base electrodes of the oscillator transistors are cross connected to provide regenerative feedback and matched resistors connect each collector to a source of operating potential. A shunt transistor is connected to the collector of one of the oscillator transistors and a series transistor connected to their common emitters. The currents of the shunt and series transistors are combined in a second current source transistor. Control signals applied to the base of the series transistor vary the oscillator current (and thereby its frequency), and produce opposite current changes in the shunt transistor, thus maintaining the DC component of the oscillator output signal at a constant.

US Patent:

41632591, Jul 31, 1979

Filed:

Dec 14, 1977

Appl. No.:

5/860505

Inventors:

Peter C. Skerlos - Arlington Heights IL

Assignee:

Zenith Radio Corporation - Glenview IL

International Classification:

H04N 544
H04N 550

US Classification:

358191

Abstract:

A television receiver includes automatic fine tuning, synchronous detection, and a "window" type tuning system. The synchronous detector has a detector oscillator which is tunable to the nominal frequency of an intermediate frequency signal derived from a received television signal. For fine tuning control, a frequency comparator receives the outputs of a fixed frequency reference oscillator and the synchronous detector oscillator and develops a control signal for locking the tuner to the frequency of a received television signal.

US Patent:

44144326, Nov 8, 1983

Filed:

Sep 21, 1981

Appl. No.:

6/304226

Inventors:

Peter C. Skerlos - Arlington Heights IL
Thomas J. Zato - Palatine IL

Assignee:

Zenith Radio Corporation - Glenview IL

International Classification:

H04M 1108

US Classification:

179 2TV

Abstract:

A television/telephone loudspeaker system is disclosed wherein feedback oscillation caused by having a speaker phone system simultaneously in the transmit and receive mode is minimized. Improved separation of transmit and receive signals is accomplished by microprocessor-controlled dynamic balancing of a bridge network coupled to a telephone isolation transformer to which the incoming and outgoing calls are provided. In addition, by microprocessor sampling of the television receiver's loudspeaker drive voltage from the telephone input line, dynamic proportional attenuation of microphone gain (AGC) is digitally accomplished in simulating full duplex operation. Bridge balancing is accomplished by means of test signals output by the microprocessor during quiet periods with various other audio signal refinements, such as room background noise cancellation, available with the constant monitoring of the microphone signal. Audio and visual indications of an incoming telephone call are provided by the television receiver's tuning system microcomputer which detects and decodes user remote commands and activates a phone relay and phone light emitting diode (LED) drivers.

US Patent:

44196628, Dec 6, 1983

Filed:

May 4, 1981

Appl. No.:

6/260639

Inventors:

Jeffery A. Puskas - Prospect Heights IL
Peter C. Skerlos - Arlington Heights IL
Thomas J. Zato - Palatine IL

Assignee:

Zenith Radio Corporation - Glenview IL

International Classification:

G09G 116

US Classification:

340750

Abstract:

A character generator driven by a microcomputer and providing latched outputs is disclosed. Flexibility in character size and character array positioning on the video display is provided for in this 60-character display generator integrated circuit. A plurality of latched outputs permits the character generator to perform additional functions while reducing the number of dedicated microcomputer outputs required to perform these and similar functions. The character generator is particularly adapted for use in a television receiver where characters are displayed on the face of the cathode ray tube.

US Patent:

44569254, Jun 26, 1984

Filed:

Oct 4, 1982

Appl. No.:

6/432464

Inventors:

Peter C. Skerlos - Arlington Heights IL
Thomas J. Zato - Palatine IL
Frank C. Templin - Arlington Heights IL

Assignee:

Zenith Radio Corporation - Glenview IL

International Classification:

H04M 1108
H04N 500

US Classification:

358 85

Abstract:

A television receiver incorporating telephone interface circuitry permitting the viewer to remotely place outgoing calls by recalling a selected number from memory is disclosed. An infrared link is used for remotely answering incoming calls, initiating outgoing calls and programming a nonvolatile memory with a plurality of preferred telephone numbers for future use. The nonvolatile memory circuit is accessed by means of a microcomputer in response to user-initiated, remotely generated commands. The television receiver's display performs a user interactive function in displaying television/telephone mode operation information, the contents of user-accessed locations in the nonvolatile memory and the telephone number being stored in memory during the programming mode of operation. The microcomputer controls not only the telephone mode of operation of the system, but also television operation in generating digital tune words in response to a channel number entry and providing these tune words to an indirect frequency synthesis type of television receiver tuner. The contents of the nonvolatile memory may be updated, or changed, as desired by user selection of appropriate controls followed by entry of the new telephone number which is presented on the video display as it is entered for user verification.

US Patent:

46332979, Dec 30, 1986

Filed:

Apr 1, 1985

Appl. No.:

6/718572

Inventors:

Peter C. Skerlos - Arlington Heights IL
Thomas J. Zato - Palatine IL
Gary A. Jones - Arlington Heights IL

Assignee:

Zenith Electronics Corporation - Glenview IL

International Classification:

H04N 900

US Classification:

358 22

Abstract:

A microprocessor based TV/TTX processor includes a stored pages ROM in the TTX processor for storing on-screen display messages and lists of functions and characteristics as pages of TTX data. An RGB switch is coupled to receive the output of a character generator in the TTX processor and to receive the video output of the TV for selectively displaying information from each source with or without the on-screen messages and lists. The stored pages ROM relieves the microprocessor of the necessity of generating the on-screen messages and lists. Items on the list are controllable by the viewer and an indication of the status of the item is given by the microprocessor changing a character in the display memory of the TTX processor.

US Patent:

41818911, Jan 1, 1980

Filed:

Jun 5, 1978

Appl. No.:

5/912790

Inventors:

Peter C. Skerlos - Arlington Heights IL

Assignee:

Zenith Radio Corporation - Glenview IL

International Classification:

H04B 126

US Classification:

325464

Abstract:

A limited-channel tuning system for a television receiver includes a memory whose activation time is directly related to its useful life. A channel address information means is coupled through an encoder to a series of flipflops which supply a first set of inputs of a corresponding plurality of comparators. The encoder also directly supplies a memory-accessing decoder and second set of inputs of the comparators. The outputs of the comparators are coupled through a NOR gate to a flipflop. The output of the flipflop supplies one input of an AND gate. A clock source drives all flipflops and the other input of the AND gate. The output of the AND gate drives a one-shot multivibrator for activating the memory with a short duration Read pulse only after a change in channel address input information occurs.

US Patent:

39461483, Mar 23, 1976

Filed:

Oct 3, 1974

Appl. No.:

5/511855

Inventors:

Peter Constantine Skerlos - Arlington Heights IL

Assignee:

Zenith Radio Corporation - Chicago IL

International Classification:

H04N 550

US Classification:

178 58AF

Abstract:

A color television receiver has a tuner converting the received signal to an intermediate frequency and fine tuning means for varying the converted frequency. An intermediate frequency filter couples the converted signal to a synchronous demodulator which includes a variable frequency reference oscillator in a closed loop control system which tracks the IF frequency thereby providing an extended range of tuning adjustment. A two pole switch is operable to couple the DC component of the closed loop control system error signal to the tuner and the AC component of the error signal to the reference oscillator thereby providing an "exact tuning" operation.