Honeywell G.m.b.h.

John E Bohan, Jr

John T Adams

Ulrich Bonne

Marvin D Nelson

Richard W Simons

James W Ratz

John L Erdman

Scott M Peterson

Frank S Mills

Brian J Hinton

Scott A Ward

Vicki L Perschbacher

Dane M Weber

A flame rectification type flame sensor circuit and method in which a generator injects periodic pulses of alternating voltage into a flame region, the voltage across the flame region being processed by a filter/amplifier which, in proper operation, produces a non-zero output signal only during the time a flame is present and a pulse of alternating voltage is being supplied by the generator. Final indication of a flame is produced only if a non-zero output signal occurs during the time a pulse of alternating voltage is being supplied, and not during the time between successive pulses of alternating voltage. Failure of an electrical component in the filter/amplifier is indicated if a non-zero output signal occurs during the time between successive pulses of alternating voltage.

Flame rectification sensor employing pulsed excitation

A fuel valve and ignitor control system in which pull-in current for a fuel valve operating on rectified alternating current is supplied through a first normally open relay whose coil is connected in series with normally open contacts of a second relay and an intermittently operating hot surface ignitor. Normally closed contacts of the second relay are connected in series with the ignitor and the fuel valve through a holding resistor, whereby actuation of the second relay provides unrectified alternating current to the ignitor and actuates the first relay to provide pull-in current to the fuel valve, and whereby deactivation of the second relay provides holding current to the fuel valve through the ignitor.

Burner control system with continuous check of hot surface ignitor

A liquid immersible electronic aquastat in which a temperature responsive element and substantially all associated electronic circuitry are arranged on a circuit board within a tubular capsule of liquid impervious material closed at one end and having a external diameter not exceeding 3/8ths of an inch so as to be interchangeable with industry standard aquastat temperature sensor mounting hardware and fittings.

Electronic aquastat in immersible capsule

A sensor fault detector for detecting a missing or shorted environment condition sensor of a plurality of sensors includes a sensor circuit for supplying a concurrent output signal from each sensor, a reference voltage circuit for supplying a predetermined reference voltage, a plurality of comparators, each of the comparators concurrently comparing a repective one of the output signals with the reference signal to produce a corresponding comparator output signal representative of a predetermined relationship between the compared signals assure the presence of properly working and connected sensors and a monitoring circuit responsive to the concurrent effect of output signals from all of the comparators to produce a control signal representative of a concurrent properly working and connected state of all of the sensors.

Sensor fault detector

A control circuit for a fuel valve in a gas fired furnace controlled by an electronic thermostat is disclosed. The thermostat requires a load current to properly operate, and a pickup and hold circuit along with a time delay circuit are integrated to control a load current circuit to provide the correct load current for the thermostat.

Thermostatically operated fuel valve control circuit

A self-energizing burner control system for a fuel burner is accomplished by heat from a pilot flame energizing a thermoelectric generator. The thermoelectric generator supplies power to an oscillator. The oscillator has an output that is stepped up in voltage level and is converted to a regulated direct current potential. The regulated direct current potential in turn is used to operate a solid state temperature control or controller. This controller has a sampling rate that is visually indicated by a light emitting diode when a proper voltage is present. The system further insures that a temperature sensor is in place, and is functioning properly.

Status indicator for self-energizing burner control system

An ultra low voltage energized oscillator for providing a stepped-up alternating current voltage is provided. This oscillator utilizes a field effect transistor with a high impedance network including a capacitor coupling a feedback signal from a secondary output winding to a primary input winding of a transformer.

Low voltage driven oscillator circuit

A self-energizing burner control system for a fuel burner is accomplished by heat from a standing pilot energizing a thermoelectric generator. The thermoelectric generator supplies power to an oscillator. The oscillator has an output that is stepped up in voltage level and converted to a regulated direct current potential. The regulated direct current potential in turn is then used to operate a solid state temperature control or controller. The controller in turn responds to a temperature at a thermistor to control a field effect transistor and series connected solenoid of a fuel valve.

Self-energizing burner control system for a fuel burner

An ignition control device that utilizes a very sensitive flame rectification signal responsive circuit is disclosed. A printed wiring board arrangement is utilized with a careful arrangement of the conductive areas on the printed wiring board to substantially eliminate leakage paths that can provide a false indication of the presence of flame when none in fact is present.

Printed wiring board means with isolated voltage source means

A temperature controller with a remote sensor having a high temperature cutoff with circuit means to prevent operation of the unit if tampered with to bypass a safety function. A remote sensor has a thermal fuse and diode feeding a pulsating D.C. voltage to a control circuit having a capacitor and an impedance means to which pulsating D.C. is fed. If the sensor unit is bypassed the thermal fuse in the controller burns out to render the controller inoperative.

Temperature controller with temperature limiting sensor

An electronic control device utilizes a plurality of conductive areas on an associated printed wiring board to create integral dew sensors. The dew sensors are created by providing parallel conductive surfaces that are connected in turn by a resistor to a high impedance switch in the form of the gate of a field effect transistor. In the event that moisture vapor or dew is present in the control device, a conductive path is created that causes the control device to shut down in a safe or alternate mode from the normal mode of operation.

Printed wiring board means with integral dew sensor

A hot surface ignitor element is functionally checked for continuity and operating temperature. This check is accomplished by initially energizing the hot surface ignitor element and then switching it as a single ended element into a series circuit with a source of potential. The potential is applied between the hot surface ignitor and an electrode which is connected back to the source of potential. If the hot surface ignitor has come up to ignition temperature a flame rectification signal is simulated.

Functional check for a hot surface ignitor element

A control device for controlling temperature conditioning apparatus is connected to a thermostatic switch means having a circuit requiring a small current to maintain the circuit active during the open cycle of the thermostat switch means. A positive temperature coefficient resistor is placed in parallel with the input circuit of the control device to provide a low input impedance to the control device for maintaining the small current without activating the control device. During the operation of the thermostat with the switch closed, a larger current to the positive temperature coefficient resistor causes the resistor to increase in temperature and thus its impedance so the wattage dissipated by the PTC resistor is reduced to minimize the heat dissipation and thus the temperature of the control.

Control device with positive temperature coefficient impedance for

With the addition of a conductive means in the form of a grounded ring or member placed at the insulator means of a high voltage spark electrode structure, the required break down voltage of the spark gap can be reduced. The conductive means typically would be a ring encircling the insulator means of the electrode structure and would provide a ground as well as a mechanical support near the end of the insulator means of the electrode structure.

High voltage spark electrode structure

A hot wire type of gas ignition system uses a negative temperature coefficient resistor-ignitor element that is deenergized after ignition has occurred. The ignition and safety monitoring of the circuit is accomplished by a second flame detector means, and the flame responsive circuit that has been disclosed in a flame rectification circuit.

Growing community of inventors

Minneapolis, MN, United States of America

John E Bohan, Jr