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: A microprocessor-based controller with synchronous reset operates in synchrony with a recurring signal coupled to its reset terminal and executes a predetermined linear program during each acive portion of the recurring signal. The controller remains in an inactive state until the recurring signal again triggers a successive active state. The controller is applicable to control applications requiring high reliability, while retaining the flexibility afforded by a microprocessor-based system. The preferred embodiments of the microprocessor-based controller are applied to combustible fuel burners employing various operating strategies.

Abstract: An electrically-powered zone condition control apparatus includes a first multiplexing means adapted for receiving analog status signals emanating from a plurality of passive signaling devices such as temperature or humidity sensors or potentiometers and transmitting these status signals in multiplex fashion to an analog-to-digital converter. The converter changes these analog status signals to digital data signals and directs them to a microcomputer. A second multiplexing means receives binary input signals which may indicate, for example, that an electrical contact is open or closed and also transmits these signals in multiplex fashion to the microcomputer. The microcomputer is adapted to perform algorithmic decisional functions relative to the signals received therein and is adaptable to periodically, selectively transmit digital output signals to one or more of a plurality of digitally-addressable load devices coupled to it by a two-wire communication bus.

Abstract: An electrically-powered zone condition control apparatus includes a first multiplexing means adapted for receiving analog status signals emanating from a plurality of passive signaling devices such as temperature or humidity sensors or potentiometers and transmitting these status signals in multiplex fashion to an analog-to-digital converter. The converter changes these analog status signals to digital data signals and directs them to a microcomputer. A second multiplexing means receives binary input signals which may indicate, for example, that an electrical contact is open or closed and also transmits these signals in multiplex fashion to the microcomputer. The microcomputer is adapted to perform algorithmic decisional functions relative to the signals received therein and is adaptable to periodically, selectively transmit digital output signals to one or more of a plurality of digitally-addressable load devices coupled to it by a two-wire communication bus.

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.