Abstract: A microprocessor circuit, and a method of monitoring and controlling an outside device using a single pin of a microprocessor, are disclosed. The microprocessor circuit includes a microprocessor having a pin, a first junction and a second junction that are both electrically coupled to the pin, and a capacitor by which the second junction is electrically coupled to the pin. The microprocessor circuit is capable of receiving at the first junction an input signal and providing a related signal to the pin in response to the input signal. The capacitor prevents signals below a certain frequency level from being communicated from the pin to the second junction. The microprocessor is capable of generating a control signal at the pin that includes at least one component that is above the certain frequency level, so that the generating of the control signal produces an output signal at the second junction.

Abstract: A method and circuit design for establishing the operating status of a direct drive, multiple speed motor. More specifically, the invention furnishes a method for providing feedback to an air distribution system indicating first whether the system motor is operating and second which speed winding has been selected. The circuit design senses the voltage differences between the speed windings of the motor and also between the first speed motor winding and the power supply. The voltage difference sensed by the circuit will determine whether a light emitting diode (LED) illuminates. The illumination of the LED indicates to the system controller whether the motor is operating and the speed winding that has been selected, thus providing the necessary feedback to the air distribution system controller.

Abstract: A microprocessor-based burner control apparatus for use in preventing incorrect ignition signals. An inverting circuit inverts and limits the magnitude of a periodic input supply voltage to create an activating signal. This activating signal is applied to the reset terminal of the microprocessor, which enters an active state during the logic high level of the activating signal and enters an inactive state during the logic low level of the activating signal. The processor is connected to the output circuits, which can only be operated during the positive half-cycle of the input supply voltage. During initial operation of the system, the microprocessor is only active during the negative half-cycle, at which time the outputs cannot be activated. The microprocessor then performs a series of tests on the system, and if all the tests are passed, the microprocessor generates an output signal.

Abstract: A circuit for producing signals representative of at least two flame current levels is disclosed herein. The circuit includes two electrodes locatable in a flame, where a voltage potential is set up between the electrodes, and the current flow is measured therebetween (flame current). The circuit includes an amplifying portion for amplifying the flame current and applying a signal to a microprocessor. The microprocessor samples the signal and outputs a signal representative of the flame current level.

Abstract: A motor controller for a recreational vehicle (RV) heating system is disclosed. The motor controller regulates the amount of current supplied to an electrical motor in a blower of the heating system in response to the operating voltage and a signal from a microprocessor. The microprocessor operates a linear program in response to a cyclical signal provided at a reset terminal. The motor controller includes a locked rotor sensor which determines if the motor is turning. The motor controller utilizes a resistor as a voltage limiting means and a field effect transistor (FET) for bypassing the resistor. The microprocessor and motor controller provide a highly reliable and readily adaptable heating system which is not disadvantageously susceptible to variations in the supply voltage.

Abstract: A microprocessor-based controller with synchronous reset including a processor for processing information having an input receiving an input signal and an output providing an output signal. The input signal conveys information about the process and the output signal controls at least one parameter related to the process. The controller includes a reset circuit for applying a reset signal to a reset terminal of the processor. The reset circuit receives a substantially constant supply signal and is responsive to reception of that supply signal to generate the reset signal, which reset signal has succeeding repetitive first and second signal levels.

Abstract: An apparatus for controlling the speed of a combustion blower motor includes first means for generating an output signal representative of a differential pressure. A second means provides a second signal representative of a desired airflow output of the blower and a summation circuit receives the first signal and the second signal and generates a command signal in response thereto. A power output circuit receives the command signal and responsively provides a regulated level of power to the motor for controlling the speed thereof. The first means may be embodied as a diaphragm-type differential pressure transmitter while the second means may be embodied as an adjustable voltage source or as a source which provides an output signal representative of a temperature.

Abstract: A differential pressure control apparatus includes a switch responsive to a pneumatic differential pressure for signaling the actuation of a blower motor. A signal generating section is provided and controls the speed of a blower for regulating the differential pressure. This section includes first means for sensing a projected light beam and second means for modulating the light beam. The first means and the second means are positionably displaceable one to the other in response to the magnitude of the differential pressure. Two preferred embodiments are disclosed.

Abstract: A microprocessor-based burner control apparatus includes an input stage adapted for controllably generating an input signal which is repetitively transitional between a first logic state and a second logic state. A synchronously controlled output stage includes a capacitor, a rectified source of alternating voltage and a microprocessor-switched transistor for controllably charging the capacitor during a half cycle of the alternating voltage having a first polarity. The capacitor is discharged during half cycles of the alternating voltage having a second polarity and the charging and discharging activity thereby actuates a load device. A programmable microprocessor is coupled to the input and output stages and is adapted to receive a synchronizing signal whereby the charging and discharging activity occurs in a predetermined relationship to the synchronizing signal. A method for controlling the operation of a combustible fuel burner is also disclosed.

Abstract: The thermostat of the present invention includes a sensor for providing a signal representative of the actual temperature within a space. A microcomputer is coupled to the sensor and intermittently utilizes power at a first level when in an operating state for controllably generating output signals in response to the temperature signal. The microcomputer is adapted to be connected to a battery as a sole power source therefor. An isolating interface device such as an electromagnetic relay is coupled to the microcomputer and is adapted for connection to temperature-affecting equipment such as a heating or cooling system controller. The relay actuates the equipment in response to output signals from the microcomputer. A voltage detection circuit may optionally be provided for signalling a low battery voltage condition.

Abstract: A runners watch which includes a lightweight case dimensioned to be worn on the wrist of the wearer. A display face is formed on the case. Clock circuitry is disposed within the case for operating the display face in order to display the time of the day, the date and elapsed time to the wearer. A sensor in the case detects the stride of the wearer when the wearer is running or jogging. Circuitry within the case is responsive to the sensor for computing the distance traveled by the wearer. Circuitry within the case is also responsive to the sensor for computing the rate of travel by the wearer. Switches are provided on the case for being operated to display the computed distance and the computed rate of travel.

Abstract: An energy conserving thermostatic control system having digitally implemented control functions for use with a heating and/or air conditioning system is disclosed. The digital thermostat includes an LCD data display for simultaneously displaying present time and ambient temperature. Slide switches are provided for setting and indicating set point information such as day temperature, night temperature, night-to-day transition time, and day-to-night transition time. The switch contacts of each slide switch are multiplexed to the display driver conductors for conveying time and temperature set point data during time and temperature scan intervals which alternate with a display interval. Strobe signals which are applied to the driver conductors are counted during the alternate scan intervals for selecting a day temperature different from a night temperature, for selecting the times which divide night from day and for providing set-back to night temperature during a predetermined time of the day.

Abstract: An energy conserving thermostatic control system having digitally implemented control functions for use with a heating and/or air conditioning system is disclosed. The digital thermostat includes an LCD data display for simultaneously displaying present time and ambient temperature. Slide switches are provided for setting and indicating set point information such as day temperature, night temperature, night-to-day transition time, and day-to-night transition time. The switch contacts of each slide switch are multiplexed to the display driver conductors for conveying time and temperature set point data during time and temperature scan intervals which alternate with a display interval. Strobe signals which are applied to the driver conductors are counted during the alternate scan intervals for selecting a day temperature different from a night temperature, for selecting the times whichdivide night from day and for providing set-back to night temperature during a predetermined time of the day.