Abstract: A control system is provided for a modulated heating system including a plurality of modulating water heaters, which may be modulating boilers. A deadband control scheme provides for reduced cycling of the modulating heater when total system heat demand falls between the maximum output of one heater and the sum of the maximum output of that one point and the minimum firing point of the next subsequent heater. Condensation of flue gas products is prevented by monitoring flue exhaust temperature for each heater and controlling the modulation of each heater to maintain a minimum heater output sufficiently high to prevent condensation of flue gas products from that heater. Rapid reaction to changes in system heat demand is provided by sensing changes in flow rate in a primary loop of the system and anticipating resulting changes in temperature thus allowing for change in heater output prior to the time the change in flow rate has fully impacted system temperature.

Abstract: A control system is provided for a modulated heating system including a plurality of modulating water heaters, which may be modulating boilers. A deadband control scheme provides for reduced cycling of the modulating heater when total system heat demand falls between the maximum output of one heater and the sum of the maximum output of that one point and the minimum firing point of the next subsequent heater. Condensation of flue gas products is prevented by monitoring flue exhaust temperature for each heater and controlling the modulation of each heater to maintain a minimum heater output sufficiently high to prevent condensation of flue gas products from that heater. Rapid reaction to changes in system heat demand is provided by sensing changes in flow rate in a primary loop of the system and anticipating resulting changes in temperature thus allowing for change in heater output prior to the time the change in flow rate has fully impacted system temperature.

Abstract: A control system is provided for a modulated heating system including a plurality of modulating water heaters, which may be modulating boilers. A deadband control scheme provides for reduced cycling of the modulating heater when total system heat demand falls between the maximum output of one heater and the sum of the maximum output of that one point and the minimum firing point of the next subsequent heater. Condensation of flue gas products is prevented by monitoring flue exhaust temperature for each heater and controlling the modulation of each heater to maintain a minimum heater output sufficiently high to prevent condensation of flue gas products from that heater. Rapid reaction to changes in system heat demand is provided by sensing changes in flow rate in a primary loop of the system and anticipating resulting changes in temperature thus allowing for change in heater output prior to the time the change in flow rate has fully impacted system temperature.

Abstract: A control system is provided for a modulated heating system including a plurality of modulating water heaters, which may be modulating boilers. A deadband control scheme provides for reduced cycling of the modulating heater when total system heat demand falls between the maximum output of one heater and the sum of the maximum output of that one point and the minimum firing point of the next subsequent heater. Condensation of flue gas products is prevented by monitoring flue exhaust temperature for each heater and controlling the modulation of each heater to maintain a minimum heater output sufficiently high to prevent condensation of flue gas products from that heater. Rapid reaction to changes in system heat demand is provided by sensing changes in flow rate in a primary loop of the system and anticipating resulting changes in temperature thus allowing for change in heater output prior to the time the change in flow rate has fully impacted system temperature.

Abstract: A control system is provided for a modulated heating system including a plurality of modulating water heaters, which may be modulating boilers. A deadband control scheme provides for reduced cycling of the modulating heater when total system heat demand falls between the maximum output of one heater and the sum of the maximum output of that one point and the minimum firing point of the next subsequent heater.

Abstract: A control system for managing and interfacing a plurality of water heaters, e.g. boilers. The control system includes a first boiler unit controlled by a first boiler control unit and a second boiler unit controlled by a second boiler control unit. The first boiler control unit is operable to coordinate the operation of the first and second boiler units in response to changes in output demand. The flues of the first and second boiler units are connected to a common flue. The control system further includes an interface and an interface control system. The interface control system communicates requests from the interface, to report and/or alter the operating parameters of the first and second boiler units, to the first and second boiler control units and communicates the request outcome(s) back to the interface.

Abstract: A control system for managing and interfacing a plurality of water heaters, e.g. boilers. The control system includes a first boiler unit controlled by a first boiler control unit and a second boiler unit controlled by a second boiler control unit. The first boiler control unit is operable to coordinate the operation of the first and second boiler units in response to changes in output demand. The flues of the first and second boiler units are connected to a common flue. The control system further includes an interface and an interface control system. The interface control system communicates requests from the interface, to report and/or alter the operating parameters of the first and second boiler units, to the first and second boiler control units and communicates the request outcome(s) back to the interface.

Abstract: A control system is provided for a modulated heating system including a plurality of modulating water heaters, which may be modulating boilers. A deadband control scheme provides for reduced cycling of the modulating heater when total system heat demand falls between the maximum output of one heater and the sum of the maximum output of that one point and the minimum firing point of the next subsequent heater.

Abstract: A control system is provided for a modulated heating system including at least one modulating water heater and a controller. A deadband control scheme provides for reduced cycling of the modulating heater when total system heat demand falls between the maximum output of one heater and the sum of the maximum output of that one point and the minimum firing point of the next subsequent heater. Condensation of flue gas products is prevented by monitoring flue exhaust temperature for each heater and controlling the modulation of each heater to maintain a minimum heater output sufficiently high to prevent condensation of flue gas products from that heater. Rapid reaction to changes in system heat demand is provided by sensing changes in flow rate in a primary loop of the system and anticipating resulting changes in temperature thus allowing for change in heater output prior to the time the change in flow rate has fully impacted system temperature.

Abstract: A method of controlling a modulating water heater supplying water to a system includes sensing a parameter which changes corresponding to a change in system flow rate, the sensed parameter being a parameter other than system temperature, and then modulating output of the heater in response to a change in the sensed parameter. Early detection of system flow rate changes permits early modulation of water heater output before the changes in flow rate have had time to significantly impact the system temperature.

Abstract: A method of controlling a modulating water heater supplying water to a system includes sensing a parameter which changes corresponding to a change in system flow rate, the sensed parameter being a parameter other than system temperature, and then modulating output of the heater in response to a change in the sensed parameter. Early detection of system flow rate changes permits early modulation of water heater output before the changes in flow rate have had time to significantly impact the system temperature.

Abstract: A control system is provided for a modulated heating system including a plurality of modulating water heaters, which may be modulating boilers. A deadband control scheme provides for reduced cycling of the modulating heater when total system heat demand falls between the maximum output of one heater and the sum of the maximum output of that one point and the minimum firing point of the next subsequent heater.

Abstract: A control system is provided for a modulated heating system including at least one modulating water heater and a controller. A deadband control scheme provides for reduced cycling of the modulating heater when total system heat demand falls between the maximum output of one heater and the sum of the maximum output of that one point and the minimum firing point of the next subsequent heater. Condensation of flue gas products is prevented by monitoring flue exhaust temperature for each heater and controlling the modulation of each heater to maintain a minimum heater output sufficiently high to prevent condensation of flue gas products from that heater. Rapid reaction to changes in system heat demand is provided by sensing changes in flow rate in a primary loop of the system and anticipating resulting changes in temperature thus allowing for change in heater output prior to the time the change in flow rate has fully impacted system temperature.

Abstract: A control system is provided for a modulated heating system including a plurality of modulating water heaters, which may be modulating boilers. A deadband control scheme provides for reduced cycling of the modulating heater when total system heat demand falls between the maximum output of one heater and the sum of the maximum output of that one point and the minimum firing point of the next subsequent heater.

Abstract: Automated charging systems for vehicles having rechargeable batteries are in common use today. Such systems typically have exposed contacts or the need for additional circuitry to move the contacts. The subject system includes circuitry which allows the charge receiving member to be only connected to the battery during charging. The charging system produces a charging signal in response to a low battery. A microprocessor receives the charging signal and responsively produces a "pulse" signal. A second transistor switch receives the "pulse" signal and responsively energizes a charging contactor coil. In response to the charging contactor coil being energized, contacts controllably block power from the battery to the motor and pass power from the receiving member to the battery.

Abstract: Electronic hourmeter devices having non-volatile memories are useful, for example, in industrial vehicles. Advantageously, such non-volatile memories should be free from a need for battery back-up systems and should minimize the number of changes of the internal memory registers. The subject electronic hourmeter apparatus includes both a dynamic memory device and a non-volatile memory device. Data is maintained in each of the memory devices and memory bit changes are minimized by utilizing a gray coded binary representation of a portion of the data and by systematically altering the addressed memory location of a portion of the data in response to one of the stored data values. Data storage occurs both periodically and in response to disconnection of the vehicle battery. Thus, the disclosed electronic hourmeter apparatus 10 advantageously maintains the integrity of the stored data, minimizes the number of bit changes that occur in the non-volatile memory device, and avoids the need for a battery back-up.

Abstract: Electronic hourmeter devices having service reminders are useful, for example, in industrial vehicles. Advantageously, such service reminders should be field programmable for a variety of predetermined service intervals. The subject electronic service reminder is readily field programmable by authorized personnel and is protected from being programmed or reset by unauthorized personnel. A service status indicator is activated in response to the elapsed hourmeter time exceeding the programmed service interval time, and both the hourmeter elapsed time and the service reminder programmed time are resettable in response to a predetermined magnetic flux applied to respective Hall effect switches. Data is advantageously maintained in a non-volatile memory device without need for a battery back-up.

Abstract: An apparatus for controllably actuating an electrical device in response to movement of a control member is useful, for example, in an industrial vehicle, including a chassis, a power supply electrically isolated from the chassis, and a steering assembly having a rotatably connected steering wheel. The subject apparatus includes a control member mounted on and rotatable with the steering wheel. An excitation circuit is provided for supplying a predetermined excitation signal to a receiving circuit which responsively produces a control signal. The control signal is modified in response to a predetermined movement of the control member. A control circuit actuates and deactuates the electrical device in response to receiving the control and modified control signals. Thus, the apparatus controllably actuates the electrical device while maintaining the control member electrically isolated from the power supply. The steering wheel is free to rotate without interconnecting wires or slip rings.

Abstract: PCT No. PCT/US80/00017 Sec. 371 Date Jan. 7, 1980 Sec. 102(e) Date Jan. 7, 1980 PCT Filed Jan. 7, 1980.This invention relates to a control system (8) for moving a frictional coupling between an engaged (15) and disengaged (17) position. A power device (40) is provided for moving the frictional coupling (18) to the engaged position (15) in response to a control device (26) being at a first position (27) and the disengaged position (17) in response to the control device (26) being at the second position (29). A switch device (70) deactivates the power device (40) at the engaged (15) and disengaged (17) position of the coupling and a maintaining device (60) releasably maintains the coupling at the engaged (15) and disengaged (17) positions. Thus the brake is held in the engaged and disengaged positions in the absence of electrical power. The control system (8) is particularly useful on a lift truck (18) parking brake system.