Abstract: An electronic thermostat includes digital electronic apparatus for simulating heat anticipation so that in operation, the temperature of the room being heated or cooled does not exhibit excessive overshoot. A sensor generates a signal representative of temperature in the room. In a preferred embodiment, the system compares the temperature signal with a composite set point signal. The composite set point signal is generated by a data processor to effect the following system characteristics: (1) when the temperature signal remains constant and is equal to the set point, the system can cycle approximately six times an hour with a fifty percent duty cycle; (2) a relatively small change in temperature or set point will modify the duty cycle substantially; and (3) if the temperature and set point signals differ by more than a predetermined amount, the system will lock on or off, depending on which is greater.

Abstract: A control arrangement for a fuel ignition system having pilot and main valves in which the energization of the operate windings of the pilot and main valves, which are connected in series, is controlled by a silicon controlled rectifier. The SCR is enabled at the start of each ignition cycle by trigger pulses provided by a pulse generating circuit and when enabled, the SCR provides a shunt circuit path around the main valve winding permitting the pilot valve winding to be energized at its operating level effecting pilot valve operation and preventing the main valve from operating. When a pilot flame is provided, a capacitor of a flame sensing network is charged by flame rectified current, generating an inhibit signal for the pulse generating circuit which causes the SCR to be cut off, interrupting the shunt path to allow the main valve winding to be energized, effecting main valve operation.

Abstract: An adapter circuit for retrofitting an oil burner control system with a flue damper includes a source of energy in circuit with the thermostat for energizing the damper motor in response to a call for heat to open the damper. A first relay in the adapter circuit includes a pair of contacts for simulating the operation of the thermostat contacts. When the damper is open, this relay is energized, and its contacts close, simulating the operation of the thermostat after the damper is opened, to energize the burner control circuit, thereby energizing the burner motor and ignition. A second relay in the adapter circuit senses whether the burner motor is energized; and when the burner motor is de-energized, this relay initiates a time delay after which the adapter circuit closes the damper.

Abstract: A vacuum operated sewage system includes a static pressure sensor establishing a trigger signal at a selected first level in a standpipe. The sensor is connected upstream of a discharge control valve and actuates a trigger and timer controller at the selected sensed pressure to establish flow for a predetermined period. A separate air admission control is provided to separately actuate the timer controller if the vacuum level in the sewage flow line drops below a selected level, to thereby reset the system vacuum pressure. The air admission control includes a level trigger valve operable to actuate the controller. A by-pass pressure sensing valve has an input connected to sense line pressure and holds the trigger valve in standby until the line pressure drops below a selected vacuum pressure. A resettable fluid timer is also connected to the level trigger valve and is charged under normal pressure system conditions.

Abstract: A motor overheating protection circuit includes an enabling circuit which responds to a trigger signal provided by a reset circuit upon application of power to the protection circuit to enable a motor drive circuit to effect energization of the motor. A temperature sensing circuit provides a control signal indicative of the temperature of the motor, and should the control signal exceed the set point of a threshold detecting circuit of the enabling circuit, indicative of overheating of the motor, the enabling circuit inhibits the motor drive circuit deenergizing the motor. Once the motor has been deenergized as the result of an overheating condition, the reset circuit maintains the enabling circuit locked out until the protection circuit is deactivated and then reactivated.

Abstract: A switch mechanism includes a fixed contact bar on which two or more contacts may be mounted. A movable contact is associated with each of the fixed contacts. Two independent toggle mechanisms are provided, each responsive to a different pressure-responsive displacement actuator for selectively actuating one or more of the movable contacts. In one embodiment having two normally open and one normally closed set of contacts, one toggle mechanism is connected by a sliding yoke to the movable contacts of one normally open set and the normally closed set, and the other toggle mechanism is connected by a second, independent sliding yoke to the movable contacts of the other normally open set and the normally closed set. Hence the normally closed contacts (which may be used to de-energize a compressor motor) are opened if either pressure limit is exceeded, but only the normally open set is disclosed which is associated with the tripped toggle mechanism. This may be used to indicate an alarm.

Abstract: A mixed air conditioning controller is formed as a factory assembled and adjusted unit in a compact housing, with simple and direct input/output field connectors. Various temperature and humidity input devices are field connected to produce a sequenced control of the air dampers and mechanical cooling and heating devices, as well as auxiliary devices. The controller includes a primary input related to room demand, an outside air temperature input, with an interlocked control to the damper, a fan status input, a minimum air supply control and a by-pass switch having a low limit input. The logic network connecting the input/output includes pneumatic switching, pressure selecting and comparing devices of a diaphragm-controlled-orifice construction connected to function as fluidic repeaters, pressure regulating valves and pressure isolating and switching devices. The controller includes a conditioning channel and a damper channel.

Abstract: An air pollutant and/or fire combustion sensing apparatus includes a charged insulating sensing electrode layer establishing an electric field as the result of electric dipoles and/or electric monopoles in or on the sensing layer. The layer has a high surface and bulk resistivity. The layer has a minimal water absorption at environmental humidities. The electric field of the sensing layer creates electrostatic sensing reactions with the gaseous products of combustion and environmental pollution and produces an amplification of the charge detection characteristic to alter the charge of the electrode. In a capacitive sensor, the sensing layer is mounted within and in spaced relation to a ground shield member. The sensing layer is thereby exposed and produces a sensitive capacitive detector for sensing of a wide spectrum of combustion products and the like.

Abstract: Heating, ventilating and air conditioning control systems commonly use pneumatic actuators. A digital logic control has first and second output ports applied to control the actuator through dual channels, including an air supply channel and an air exhaust channel. Various sensed and related input signals are processed by the logic device and generate control signals at the control signal ports. Each channel includes an electrically controlled switch unit having an electrical operator and a pneumatic switch for controlling the flow to and from the pneumatic actuator. The switch may take the form of an electromagnetically actuated flow valve opening and closing a flow path from a supply or exhaust to the pneumatic actuator or, in the case of the supply channel, the form of a small electrically operated pump unit. The actuation of the actuator is controlled either on a time or frequency basis to set the actuator in the proper position.

Abstract: An arrangement for a direct ignition type fuel ignition system includes a capacitive timing network which enables a flame relay to operate during a trial for ignition interval, energizing a fuel valve to supply fuel to a burner for ignition, and a flame sensing circuit which causes the flame relay and the fuel valve to be maintained operated only if a flame is sensed before the end of the trial for ignition interval. In the absence of a flame, a diode, back biased by the timing signal, decouples the flame sensing circuit from the timing network. When a flame is established, a further diode, back biased by a control signal provided by the flame sensing circuit, decouples the timing network from the flame sensing circuit. In an embodiment wherein the charging time of a capacitor defines the trial for ignition interval, a fast reset circuit provides rapid discharge of the timing capacitor when power is removed from the timing network.

Abstract: A vacuum operated sewage system includes a static pressure sensor establishing a trigger signal at a selected first level in a standpipe. The sensor is connected upstream of a discharge control valve and actuates a trigger and timer controller at the selected sensed pressure to establish low for a predetermined period. A suitable time delay capacitor in the controller prevents transient signal actuation. A system pressure interlock senses the vacuum level of the system to disable the timer controller if system pressure is below a selected level. The interlock may include a pressure level control valve connected to bleed the capacitor and disable the timer controller. A system pressure sensing valve in parallel with the level control valve decouples the latter as long as the system level is above the selected minimum and thereby permits normal controller operation.

Abstract: A passive thermal energy storage cell includes a container formed of suitable material. The container is filled substantially with a supercoolable material such as ethylene carbonate or a phase change material for storage of solar energy or the like. The container includes mechanical passive nucleating elements such as sharp pointed asperities on the wall, cold fingers or pointed members secured within the tank in continuous activating engagement with the supercoolable material to prevent supercooling thereof. Exchange elements are coupled to the supercoolable material for introduction of heat from a solar collector and removal of heat to a load. The material may be heated by the solar energy to or above melting temperature to store heat.

Abstract: The illustrated embodiment is electronic. It includes circuitry for simulating heat anticipation so that in operation, the temperature of the room being heated or cooled does not exhibit excessive overshoot. A signal is generated representative of a desired set point, and another signal is generated representative of room temperature. An output signal, derived from a comparison circuit, is either ON or OFF. An integrator is reset each time the output signal is switched and generates a ramp voltage of increasing magnitude and having a polarity tending to reverse the state of the comparison circuit. The comparison circuit generates an ON signal when the set point signal is greater than the combined temperature and ramp signals; and it generates an OFF signal when the set point signal is less than the combined signals. The comparison circuit latches up once it has switched to avoid hunting or chatter.

Abstract: An air pollutant and/or fire combustion sensing apparatus includes a sensing electrode having an electrically non-conductive or dielectric sensing layer which has a surface resistivity in excess of 1.times.10.sup.10 ohms/square (and preferably 1.times.10.sup.15), and a bulk resistivity in excess of 1.times.10.sup.12 ohm-cm, and preferably 1.times.10.sup.15 at 50% R.H., and which is essentially free of dipole-hydrogen bonding forces such that the surface energy component is primarily due to dispersion bonding forces and, if at all, only incidentally as a result of dipole-hydrogen bonding forces. The latter appears to be a principal factor and desirably has a value of less than 5.0 ergs/cm.sup.2 and preferably less than 1.0 erg/cm.sup.2. The gases detected have a large Van der Waal gas "a" constant and dipole moment. This sensing layer adsorbs air borne polar constituents to alter the charge on the electrode.

Abstract: A fuel ignition control system including a control arrangement for operating pilot and main valves of the system the pilot valve being operated to permit a pilot flame to be established, and the main valve being operated by a pilot flame sensing circuit which includes a controlled switching device enabled in response to the charging of a capacitor to a given value to effect the operation of the main valve, the charging of the capacitor being controlled by a further controlled switching device which supplies AC current to the capacitor in the absence of a pilot flame, preventing the capacitor from charging to the given value, and which supplies DC current to the capacitor when a pilot flame is established, permitting the capacitor to charge to the given value.

Abstract: A furnace ignition and draft control system includes a damper plate movable under control between a closed and an open position. When a call for heat signal is generated, a holding relay is actuated to energize a damper motor to open the damper provided the damper plate was closed when the signal was generated, otherwise the system will not operate. After the damper is run to the full open position and this is proved, a fuel control circuit is actuated to supply fuel to the furnace, and a trial-for-draft period is initiated. A draft controller energizes the damper motor to open the damper if draft is less than a first predetermined value and to close the damper if draft is greater than a second predetermined value. The predetermined draft values define a desired draft range in which the damper is not operated.

Abstract: A method of making an element for sensing the presence of nitrogen dioxide gas in the environment. The element is formed by heating a film of an electrically non-conductive polyaromatic polymer to a temperature sufficiently high to pyrolyze the polymer and render the polymer semi-conductive. The pyrolyzed film is mounted on an electrically non-conductive base. Electrical leads are attached at spaced locations to the film and are connected in an electrical circuit with a signalling or control mechanism. The presence of nitrogen dioxide gas will cause a change in the electrical characteristics of the film to thereby activate the mechanism. A heating element can be associated with the base to insure constant temperature and humidity conditions.

Abstract: When a call for heat is established, a flame relay is actuated for a predetermined time by means of a cycling timer. Upon this initial actuation, the flame relay inhibits a checking relay and initializes a trial-for-ignition (or simply "ignition") timer. After the cycling timer times out and the flame relay has been completely cycled, which established operativeness of the flame relay and flame sensing circuitry, the checking relay is enabled and actuated for the ignition period. The checking relay then actuates the pilot valve and a spark generator to start a pilot flame. If a flame is sensed, before the ignition timer times out, the flame relay actuates the main valve and establishes a holding current for the ignition timer so that the checking relay continues to be energized. If a flame is not sensed during the trial period, the ignition timer disables the checking relay, thereby de-energizing the pilot valve before the main valve is opened.

Abstract: A solid state motor control circuit for controlling the operation of a servo motor comprises a comparator circuit including a differential amplifier having its inputs connected across terminals of the motor and having its output connected to a drive circuit the output of which is connected to a supply terminal of the motor. A reference circuit maintains a reference terminal of the motor at a reference level, and in the absence of a command signal, the differential amplifier and drive circuit maintain the voltage at the motor supply terminal at the reference level. A control switch enabled by the command signal applies a control signal to an input of the differential amplifier, and the differential amplifier responsively enables the drive circuit to raise or lower the potential at the motor supply terminal relative to the reference level, thereby energizing the motor.

Abstract: A control valve includes a single diaphragm as a common wall between an input signal chamber having an input port and an output chamber having a central supply port and an exhaust orifice. The orifice has a seating face parallel to and spaced from the diaphragm. A spring-loaded ball valve unit in the supply passage is aligned with an operator moving with the diaphragm. An increasing input signal first moves the diaphragm to close the exhaust orifice and thereafter moves the operator to open the supply valve. Pressure builds in the output chamber, tending to return the diaphragm and close the supply valve until the output and pilot pressure are balanced. The supply valve then closes. As the exhaust is sealed off, this effectively seals the output chamber. If the signal decreases, the diaphragm uncovers the exhaust orifice until a new balanced state is created.