Abstract: A touch-screen control panel interface has a dielectric flat or curved front panel and a printed circuit board with a front side and a reverse side which is the component side. Alphanumeric display module(s) or an LCD display and optional protective cap mounted on the reverse side of the circuit board are visible through window cutout(s) on the board. An array of LED indicators can be mounted on the back side of the circuit board and visible through cutouts in the board. Metallized capacitive pads on or adjacent the back side of the front panel at touch locations permit selection of various modes, functions, and settings. These pads may be formed on the flat front side of the circuit board, on the back of the front plate, or on an intermediate membrane. A microprocessor is connected with the various components and with capacitive pad. Icons may be printed onto the flat panel, in registry with the metallized capacitive electrode pads.

Abstract: A battery powered thermostat senses a battery voltage drop to a low-battery voltage level. At that point, the thermostat microprocessor provides a LOW BATTERY alert message, visible on the thermostat display. If the occupant fails to replace the power cells or does not notice the LOW BATTERY message, when the battery voltage drops further the microprocessor alters the thermostat set points. This reduces the number of heating or cooling cycles per day, and reduces the number of actuations of the latching relays in the thermostat, conserving remaining battery life. At a further drop in battery voltage the set points are changed additionally. Additional functions, such as second level heat, second level cooling, and fan speed, are disabled. The change in heat or cooling cycles induces the occupant to check the thermostat where he or she will notice the LOW BATTERY message.

Abstract: A furnace controller circuit includes a microprocessor with input ports and output ports including ports to issue control signals for actuation of inducer, gas burner, and furnace blower. A temperature-actuated limit switch commences a furnace shut-down sequence when the temperature of the furnace heat exchanger exceeds a predetermined limit temperature, and then resets to permit a turn-on sequence. An LED visible fault indicator is coupled to the microprocessor to provide visible fault messages. A non-volatile memory device coupled with the microprocessor is operative to store fault indications when present. In the event of power restoration after power failure, the limit switch status and other fault status are maintained. A lockout period is computed based on length of furnace run time until fault and recent fault history. Limit switch and other safety faults are recorded and these can be weighted and ranked based on age of each fault occurrence.

Abstract: A touch-screen control panel interface has a dielectric flat or curved front panel and a printed circuit board with a front side and a reverse side which is the component side. Alphanumeric display module(s) or an LCD display and optional protective cap mounted on the reverse side of the circuit board are visible through window cutout(s) on the board. An array of LED indicators can be mounted on the back side of the circuit board and visible through cutouts in the board. Metallized capacitive pads on or adjacent the back side of the front panel at touch locations permit selection of various modes, functions, and settings. These pads may be formed on the flat front side of the circuit board, on the back of the front plate, or on an intermediate membrane. A microprocessor is connected with the various components and with capacitive pad. Icons may be printed onto the flat panel, in registry with the metallized capacitive electrode pads.

Abstract: A baseboard radiator element is formed of an aluminum tube and fins or vanes of aluminum sheet. An elongated strip of sheet aluminum is bent into a fin assembly of generally rectangular fins alternating with spacer members, with the fins having central apertures. The fin assembly is placed into a fixture and the tube is forced through the aligned apertures to create strong mechanical and thermal contact between tube and fins. The fin structure can be used with center tubes of other materials. A brass or steel connector insert is fitted into the end of the aluminum tube, and the end of the tube is deformed inward using a collet or jaw device to create a hermetic seal with the tube. The process can also be used for joining aluminum tubing to tubing of aluminum or other materials.

Abstract: A voltage or power conditioning and control device may be used in line with a source of AC line power and a reactive load such as a single-phase induction motor. The device operates to absorb some of the power reflected by the AC load and generate a synthetic power wave to supplement and correct the applied power in level and phase. The device employs a pair of power capacitors, and a pair of electronic switch devices each with a diode in parallel. Gating or command signals are generated based on the line voltage and timing, e.g., zero crossings. The phase or timing of the command signals is selected for a normal or no-boost mode, a voltage boost mode, or a voltage reduction mode. The capacitors are considered in series with the load, and improve the power factor to the load. A variation of this device may be used in conjunction with a solar array or other local power source.

Abstract: A motor start circuit for an AC induction motor employs a DC relay whose NC contacts are placed in series with the start capacitor. A half full-wave rectifier arrangement has an AC input connected to the junction of the relay switch and the start capacitor, and DC outputs applied across the relay actuator coil. In the event of intermittent application of power to the motor, any residual charge on the start capacitor will feed current to the actuator coil to hold the relay switch open until the residual charge has decayed sufficiently, to avoid damage to the motor from capacitive discharge. A high magnetic retentivity core can be used to hold the relay off for sufficient time for stored energy to dissipate.

Abstract: A wall plate for a wall thermostat blocks intrusion air from the thermostat. The wall plate has a wire passage aligned with the wall penetration through which the thermostat wires emerge. The wall plate member directs any intrusion air that flows out the penetration away from the cavity of said thermostat. An insulating layer, e.g., a closed-cell foam sheet, in the wall plate insulates the thermostat from direct thermal contact with the wall. The closed-cell material closes around the thermostat wires. Bosses or feet on the thermostat back plate create a standoff between the wall plate and the thermostat.

Abstract: A plug or grommet fits into the opening in the back plate of a thermostat and blocks or diverts intrusion air from entering the interior of the thermostat housing from the wall penetration for the thermostat wires. The thermostat wires are fed through the grommet, which is a soft rubbery material that closes over the wires and blocks the intrusion air. Alternatively, a wall plate can be used between the back plate of the thermostat and the wall where the thermostat is mounted.

Abstract: A plug or grommet fits into the opening in the back plate of a thermostat and blocks or diverts intrusion air from entering the interior of the thermostat housing from the wall penetration for the thermostat wires. The thermostat wires are fed through the grommet, which is a soft rubbery material that closes over the wires and blocks the intrusion air. Alternatively, a wall plate can be used between the back plate of the thermostat and the wall where the thermostat is mounted.

Abstract: An actuation circuit for an electromechanical relay employs a microprocessor and a switching transistor to actuate a relay over a wide range of applied voltages. The switching transistor is connected in series with the actuator coil. A voltage sensing circuit is connected to one input of the microprocessor, which produces a pulse-width modulated actuator output to gate the switching transistor. The microprocessor is suitably programmed so as to produce a pulse width modulated signal actuator signal whose duty cycle is a function of applied voltage. The RMS current through the relay coil is sufficient to ensure good actuation, but does not overstress the coil. The relay is selected to have its rated actuation voltage at or below a lower end of the expected range of applied voltages. A relay actuation boost arrangement can include a transistor or an SUS (silicon unidirectional switch) or similar negative resistance device.

Abstract: An arrangement for driving actuator coils for two or more driven devices employs a microprocessor or similar controller and an actuator driver circuit. The actuator driver circuit controls two or more relay actuator coils from a single microprocessor output terminal. This output terminal can provide a high, low, or pulse output signal. An amplifier switching device, such as a transistor, whose base is coupled to the output terminal of the microprocessor, drives the first relay actuator coil as its load. A rectifying diode is connected to one end of a capacitor and thence through a negative resistance device to a second relay actuator coil or other driven device. The coil impedances are selected so that the second coil has a significantly higher impedance than the first coil. When output pulses appear at the microprocessor output terminal, the transistor switch pulses on and off, and thus energizes the first coil.

Abstract: Arrangement for dc signaling between a transmitter or transceiver over a single pair of conductors to another transceiver or receiver of similar design. The conductors carry a dc communications voltage at a level V.sub.comm (e.g., 24 to 35 volts dc) and power for the tranceivers, receivers and/or transmitters of the system. The transceiver comprises a microprocessor having a signal input terminal V.sub.in, a signal output terminal V.sub.out, a sensor input circuit coupled to a sensor transducer, e.g., a temperature sensor, and a control output circuit coupled to control an external device, e.g., a furnace relay. A voltage limiting circuit device coupled to the pair of conductors supplies the microprocessor with a supply voltage V.sub.dd at a predetermined level (e.g., 5 volts dc) less than the communications voltage level V.sub.comm.