Abstract: An electronic control (8) is shown adapted for use with gas furnaces which controls function and speed(s) of an induced draft motor (44), an igniter source (13), gas valve(s) (14), and function and speed(s) of a blower motor (21) based on inputs from a room thermostat, various sensor and safety devices, and proper sequence/position/change of position timing of these inputs. The control is capable of detecting and saving for recall specific errors and faults that occur while in service. The control can communicate warnings, faults, and errors, as well as safety lock-out conditions in various ways including a Light Emitting Diode (LED) (9), as a generic fault condition through a set of dry contacts (45a), or as very specific fault conditions through a communications interface (H4). The control provides other benefits to the installer, occupants of the space, and service technicians including selectable igniter warm-up times, user selectable fan On speed and blower delay-off times.

Abstract: An electronic control (8) is shown adapted for use with gas furnaces which controls function and speed(s) of an induced draft motor (44), an igniter source (13), gas valve(s) (14), and function and speed(s) of a blower motor (21) based on inputs from a room thermostat, various sensor and safety devices, and proper sequence/position/change of position timing of these inputs. The control is capable of detecting and saving for recall specific errors and faults that occur while in service. The control can communicate warnings, faults, and errors, as well as safety lock-out conditions in various ways including a Light Emitting Diode (LED) (9), as a generic fault condition through a set of dry contacts (45a), or as very specific fault conditions through a communications interface (H4). The control provides other benefits to the installer, occupants of the space, and service technicians including selectable igniter warm-up times, user selectable fan On speed and blower delay-off times.

Abstract: An electronic control (8) is shown adapted for use with gas furnaces which controls function and speed(s) of an induced draft motor (44), an igniter source (13), gas valve(s) (14), and function and speed(s) of a blower motor (21) based on inputs from a room thermostat, various sensor and safety devices, and proper sequence/position/change of position timing of these inputs. The control is capable of detecting and saving for recall specific errors and faults that occur while in service. The control can communicate warnings, faults, and errors, as well as safety lock-out conditions in various ways including a Light Emitting Diode (LED) (9), as a generic fault condition through a set of dry contacts (45a), or as very specific fault conditions through a communications interface (H4). The control provides other benefits to the installer, occupants of the space, and service technicians including selectable igniter warm-up times, user selectable fan On speed and blower delay-off times.

Abstract: A battery pack having an electrical circuit including a battery array of one or more batteries, a thermostat switch, and a positive temperature coefficient resistor (PTCR). Preferably, the thermostat and PTCR are disposed in a trianguloid channel formed by the nip of adjacent cylindrical batteries in a multiple battery pack so that the finished pack may have the same size and shape as a non-protected pack for the same application. Preferably, the batteries are rechargeable and the pack includes a charging plug connected across the battery array in series with the thermostat and PTCR. Preferably, the pack is wrapped in a film of a heat-shrinkable polymer to provide physical integrity.

Abstract: A self-contained, high power, solid state, battery voltage switching system applies battery voltage to a thermal printhead when the printer is turned on and disconnects voltage from the battery to the thermal printhead when the printer is turned off, thereby conserving battery power and increasing battery life. FET switches connect the battery to the printhead and to a circuit for applying operating voltage to a drive and control circuit for the printhead. Gate voltage is applied to the FET, or FETs when a plurality thereof are connected in parallel, to enable the FETs to provide the connection between the battery and the printhead. The gate voltage is supplied from a flip-flop and a FET driver which are self-contained with the FETs and the other circuitry in the printer.