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| Number | Title | Issue Date |
| 4587590 | Microcomputer driven fail-safe device with short circuit detection for electronic control circuitry A fail-safe device for removing power from controlled circuitry upon the occurrence of an undesired operating condition is disclosed. The fail-safe device includes means for detecting a short circuit in the controlled circuitry and for indicating the exis... | 05/06/1986 |
| 4482312 | Burner control system A burner control apparatus for use with a furnace installation that has an operating control to produce a request for burner operation, a flame sensor to produce a signal when flame is present in the monitored combustion chamber, one or more devices for c... | 11/13/1984 |
| 4398233 | Fail-safe device for electronic control circuit A fail-safe device is disclosed for removing power from circuitry to be controlled upon the occurrence of an undesired operating condition. The device includes circuitry for generating a fail-safe signal that is normally within a predetermined frequency r... | 08/09/1983 |
| 4395224 | Burner control system A burner control apparatus for use with a fuel installation that has an operating control to produce a request for burner operation, a flame sensor to produce a signal when flame is present in the monitored combustion chamber, and one or more devices for ... | 07/26/1983 |
| 4395638 | Self-checking flame failure control This invention relates to control circuits of the type which continuously monitor their own performance so as to be self-checking, i.e., to produce a response whenever the system shows the absence of a condition being monitored or a change therein and als... | 07/26/1983 |
| 4295129 | System condition indicator A system condition indicator for monitoring a number of interlock switches and fuel valves to detect what event first occurs to shut down a burner control system. The monitoring circuitry is periodically strobed once each cycle of the power line signal an... | 10/13/1981 |
| 4280184 | Burner flame detection Method and apparatus for evaluating the quality of a flame in response to outputs from a flame sensor. The present invention includes a method and apparatus in which output pulses from a flame sensor are continuously counted.The number of pulses is accumu... | 07/21/1981 |
| 4272725 | Interface circuit for use with electronic control devices An interface circuit for indicating the state of a set of switch contacts having high noise immunity and high reliability. The switch contacts to be monitored are connected in series with the primary winding of a transformer having a magnetic core with a ... | 06/09/1981 |
| 4249884 | Burner control apparatus with stabilized pilot flame timing interval Burner control apparatus includes a control device for actuating an ignition control means, and a timing circuit for providing an ignition timing interval which extends beyond flame detection for a timed interval. The timing circuit is actuated in respons... | 02/10/1981 |
| 4243372 | Burner control system A burner control apparatus for use with a furnace installation that has an operating control to produce a request for burner operation, a flame sensor to produce a signal when flame is present in the monitored combustion chamber, and one or more devices f... | 01/06/1981 |
| 4137035 | Burner control apparatus Burner control apparatus includes control devices for actuating an ignition control means, and a timing circuit for providing an ignition timing sequence of four precise intervals. The timing circuit is actuated in response to a request for burner operati... | 01/30/1979 |
| 4113419 | Burner control apparatus Burner control apparatus includes a control device for actuating an ignition control means, and a timing circuit for providing an ignition timing interval of precise duration. The timing circuit is actuated in response to a request for burner operation an... | 09/12/1978 |
| 4110608 | Two-terminal photodetectors with inherent AC amplification properties A two-terminal photodetector comprising a photodiode and a plurality of active and passive components connected so that when connected to a source of current the voltage across the terminals is proportional to the illumination and is proportional by an am... | 08/29/1978 |
| 4101452 | Lead sulfide activation process 1. The process of photosensitizing lead sulfide comprising adding a persulfate solution to intermixed solutions of thiourea, lead acetate and sodium hydroxide whereby activated lead sulfide is precipitated therefrom.... | 07/18/1978 |
| 4039844 | Flame monitoring system A flame monitoring system includes a flame sensor for producing a flame signal as a function of flame conditions in a monitored environment and flame signal enhancing circuitry coupled to the flame sensor. The flame signal enhancing circuitry has a first ... | 08/02/1977 |
| 3995221 | Flame responsive system A flame responsive system includes a flame sensor, flame signal generating circuitry responsive to the flame sensor and flame signal inhibiting circuitry also responsive to the flame sensor. A fast filter and a slower filter are coordinated so that total ... | 11/30/1976 |
| 3967904 | Precision radiation source regulation circuit A precision lamp regulation circuit includes a source of AC power, a lamp connected in circuit with the AC source, a transistor switch connected in circuit between the AC source and the lamp, a light sensor optically coupled to respond to the radiation ou... | 07/06/1976 |
| 3958126 | Logic circuitry A burner control system has a field device and control logic for providing a control signal to change the state of the field device. A comparator that compares signals from field and the control logic comprises translation circuitry that is arranged to pr... | 05/18/1976 |
| 3954383 | Burner control system A burner control system in which signals indicating the condition at various locations within the system are applied to a control circuit in the form of pulse trains, causing a continuous alternation of state of solid state switching elements therein. The... | 05/04/1976 |
