Thomas J Glad

57129770, Jan 27, 1998

Sep 18, 1995

8/529867

Thomas J. Glad - Nevada City CA
Gregory S. Gillespie - Nevada City CA
David R. Kissinger - Pike CA
William L. Harris - Nevada City CA

TDK Systems, Inc. - Nevada City CA

H04N 132
G06F 1314

39520009

The present invention provides apparatus and method for connecting Data Terminal Equipment (DTE) to communication networks. The present invention provides an adaptable universal modem that can be reconfigured to meet different specifications in different countries, thereby allowing a user to use a single universal modem across different specifications in different countries. The universal modem includes a microcontroller, a programmable data pump, and a programmable DAA. A user reads a particular country code on each country's unique identifier and provides the information to a modem setup program. The modem setup program configures the universal modem according to the country information entered by the user, thereby permanently storing the home country code in modem flash memory. The universal modem of the present invention reverts to a default home configuration upon power-up to meet the requirements of various PTT (Postal Telephone & Telegraph) authorities. The country code can be changed after power-up by entering a country code change command in the modem setup program.

46911723, Sep 1, 1987

Sep 10, 1985

6/774544

Kiyoshi Fukahori - Grass Valley CA
Thomas Glad - Grass Valley CA

Silicon Systems, Inc. - Tustin CA

H03G 320

330129

An apparatus for adjusting the amplitude of an electronic signal to a predetermined level in a MOS integrated circuit device. A variable amplifier comprising a plurality of operational amplifier stages whose gain is controlled by capacitor ratios is utilized to amplify an input signal. The output of the variable amplifier is coupled to a comparator comprising a single operational amplifier to compare the output with a reference signal level corresponding to the desired output level of the circuit. The comparator generates an instruction signal to a flip-flop circuit and an up/down counter to provide digital control to the amplifier gain stages. The digital bits of the counter, depending on whether high or low, selectively switch the appropriate capacitors into operation to vary the gain of each operational amplifier stage.

56664311, Sep 9, 1997

May 10, 1994

8/240860

Gregory S. Gillespie - Nevada City CA
Thomas J. Glad - Nevada City CA

TDK U.S.A. Corporation - Port Washington NY

H03G 300

381109

Method and apparatus for controlling the volume of an internal PC speaker. In the present invention, pulse width modulation (PWM) techniques are used to selectively reduce the signal power generated at the speaker. By substituting a high frequency signal having a symmetric duty cycle for portions of the digital audio signal, the average signal power is reduced. The frequency of the substitute signal is much higher than the speaker bandwidth, contributing negligible power to the output. The ratio of audio signal to high frequency signal determines the output signal level. In the preferred embodiment of the present invention, a three bit counter is used to separate the audio signal into intervals having eight states apiece. A signal providing -6 dB of attenuation is generated by substituting the toggling output from the least significant bit of the counter during four out of the eight states. A signal providing -12 dB of attenuation is generated by substituting the same toggling output during six out of the eight states.