Texas Instruments Corporation

US Government As Represented by the Secretary of the Army

Walter H Bailey

Mitchell R Rowlette

Ronald E Garnett

Youn H Ting

Mark Eric Miller

Dennis D Buss

Kent Pettus

A control used in a two stage HVAC system has a power supply from a 24 VAC transformer which is full wave rectified (D D D D ) to create DC voltages for a microcontroller (U ) and relays (K -K ). All of the control information needed for the two stage control system is sent to the control from a room thermostat ( ) having first and second stage cooling signal terminals (Y , Y ) over a single line by connecting a diode between the Y , Y terminals creating separate microprocessor recognizable signals.

Method and apparatus for wiring room thermostat to two stage HVAC system

A gas fired furnace system (10) has a controller (14) controlling the supply of gas through a gas valve (12) and air for combustion by means of an induced air draft fan (28), ignition of the gas by means of ignitor (22), the delivery of heated air from a heat exchanger (20) by means of an air blower (34) in response to signals from a thermostat (42). A selected constant flow of air for combustion is provided by controlling the speed of the motor driving the induced motor fan (28) despite changes which may occur in back pressure. Induced draft fan motor parameters proportional to motor torque and motor speed are read on an ongoing basis and inputted to controller (14) which computes a desired voltage and compares that with referenced data stored in the controller memory and makes corrections to the speed of the induced draft fan motor to maintain the constant air flow. The motor speed and motor torque are also monitored to ensure that they are within selected limits indicative of safe operation and responsive to this input energization of a relay (KM1) is controlled to deenergize the gas valve and ignition.

Method for controlling an induced draft fan for use with gas furnaces

Induced draft fan control for use with gas furnaces

A temperature control system is shown in which a thermostat circuit is combined with a power supply to produce a higher anticipator current for a W1 signal while reducing power consumption and heat generation of the circuit. A first relay power signal is provided by an unbalanced bridge rectifier (D1, D2, D3, D4, D7, D8) while current drawn through the anticipator resistor (AR1) by means of an additional bridge rectifier circuit (D7, D8, D9, D10) is merged with the first relay power signal. In a second embodiment, an unbalanced bridge rectifier (D1, D4, D7, D2, D3, D8) has an output connected to a first stage relay power signal line as well as to second and third relay power signal lines. A second stage of the power supply includes a first additional bridge rectifier (D5, D6, D7, D8) connected to the second relay power signal line that drives current through the W1 anticipator while in a third stage of the power supply a second additional rectifier (D20, D21, D7, D8) is connected to the third relay power signal line and draws current through the W2 anticipator. Each stage of power adds more capacitance (C12, C11, C10) as the power requirements increase.

Electrical control system for relay operation responsive to thermostat

A redundant power supply system wherein the standby power supplies are maintained in a powered up state at all times by feeding back a difference signal which is indicative of the voltage difference between the output of the power supply and a further difference voltage. The further difference voltage is indicative of the voltage drop across a diode located between the output from the power supply and the load of the entire power supply system.

Redundant power supply control

A constant false alarm rate is achieved in a moving-target-indicator radar y controlling the threshold in doppler channels according to the level of clutter in range gates near the range rate being examined for the presence of a target. Processing is simplified by using analog signals in charge coupled devices for target detection.

Adaptive threshold detection utilizing a tapped charge transfer device

An improved charge transfer device signal processing system is disclosed. In one aspect of the invention the signal at each node of a bucket brigade delay line is detected to provide a continuous output signal over a major portion of a cycle of a multiphase clock. In a different aspect of the invention the signals detected at the respective nodes of a matched filter are selectively summed to negative or positive summation busses to provide an electronically programmable matched filter. In still a different aspect of the invention a charge transfer device matched filter is provided in which both the magnitude and sign of the respective weighted signals can be selectively controlled. There is also provided an improved configuration for detecting the charge required to recharge the two different electrode portions of a split electrode weighted charge coupled device matched filter.

Charge transfer device signal processing system

A variable tap weight convolution filter comprised of charge transfer devices which may be charge coupled devices, bucket brigade devices or a combination of the two, for performing convolutions of an input signal with tap weights from a second input signal, said tap weights varying as a function of time.

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Versailles, KY, United States of America

Walter H Bailey