US3753043A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Condition responsive control apparatus
Assignee: Texas Instruments Inc
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Filing: 1972-04-12
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Granted: 1973-08-14
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Expires: 1992-04-12
Abstract
Abstract A circuit is disclosed for determining, after a predetermined period of time has elapsed following the energization of a load, such as an air-conditioning compressor, whether a certain condition exists, such as whether operating oil pressure level has been reached in the compressor, and for shutting down and locking out the air-conditioning system if the condition does not exist. The circuit is reset either by removing power therefrom or by actuating a push button switch. In one embodiment a pressure switch is employed to determine the oil pressure level while in another embodiment a temperature dependent resistor is used to determine the presence of the oil. The circuit can be used in conjunction with another circuit for controlling the energization of the compressor motor dependent upon the temperature of the winding of the motor or other desired parameters to be monitored.
Inventors
- 👤 L Plouffe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:55
CPC Classifications
H; H02; H02H; H02H5/00; H02H5/04; H02H5/042; H02H5/08; H02H5/086
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
368 words
Control apparatus for testing for the existence of a condition after a predetermined period has elapsed following the energization of a load and for deenergizing the load should the condition exist when tested comprising: a tapped secondary winding of a transformer, first and second resistances serially connected to form a voltage divider and forming a junction therebetween, the secondary winding and the voltage divider forming a bridge circuit, voltage responsive switch means connected between the tap of the secondary and voltage divider junction; relay means for controlling the flow of electrical power to the load, the relay means including a control circuit; an electronic element having an output circuit and an input circuit for controlling the conductive state of the output circuit, the output circuit of the electronic element being interconnected with the control circuit of the relay means, the operation of the relay means being dependent upon the conductive state of the electronic element; voltage responsive switch means having an output circuit and an input circuit, the input circuit connected to the voltage divider junction, the output circuit connected between a power supply and a common point; timing means comprising a capacitor-resistor combination having a timing junction, the capacitor-resistor combination being coupled between commOn and the output circuit of the voltage responsive switch means; a condition responsive switch means coupled between the timing junction and common; a detector circuit coupled to the timing junction and having an on-off output coupled to the input of the electronic element to control the conductivity of the output circuit of the electronic element; and the voltage divider junction responsive to the state of energization of the relay means causing the voltage responsive switch means to conduct when the relay means is not energized preventing actuation of the timing means, the voltage responsive switch means being non-conductive when the relay means is energized thus permitting actuation of the timing means, the capacitor building up a charge when the condition responsive switch is open causing the detector circuit to produce an output making the electronic element conductive, when the condition responsive switch means is closed the capacitor charge is drained causing the detector circuit to produce no output making the electronic element non-conductive.
Claim 2
Dependent Claim
368 words
Control apparatus for testing for the existence of a condition after a predetermined period has elapsed following the energization of a load and for deenergizing the load should the condition exist when tested comprising: a tapped secondary winding of a transformer, first and second resistances serially connected to form a voltage divider and forming a junction therebetween, the secondary winding and the voltage divider forming a bridge circuit, voltage responsive switch means connected between the tap of the secondary and voltage divider junction; relay means for controlling the flow of electrical power to the load, the relay means including a control circuit; an electronic element having an output circuit and an input circuit for controlling the conductive state of the output circuit, the output circuit of the electronic element being interconnected with the control circuit of the relay means, the operation of the relay means being dependent upon the conductive state of the electronic element; voltage responsive switch means having an output circuit and an input circuit, the input circuit connected to the voltage divider junction, the output circuit connected between a power supply and a common point; timing means comprising a capacitor-resistor combination having a timing junction, the capacitor-resistor combination being coupled between commOn and the output circuit of the voltage responsive switch means; a condition responsive switch means coupled between the timing junction and common; a detector circuit coupled to the timing junction and having an on-off output coupled to the input of the electronic element to control the conductivity of the output circuit of the electronic element; and the voltage divider junction responsive to the state of energization of the relay means causing the voltage responsive switch means to conduct when the relay means is not energized preventing actuation of the timing means, the voltage responsive switch means being non-conductive when the relay means is energized thus permitting actuation of the timing means, the capacitor building up a charge when the condition responsive switch is open causing the detector circuit to produce an output making the electronic element conductive, when the condition responsive switch means is closed the capacitor charge is drained causing the detector circuit to produce no output making the electronic element non-conductive.
Claim 3
Dependent Claim
187 words
Control apparatus for testing the existence of a condition after a predetermined period has elapsed following the energization of a load for producing a voltage signal should the condition exist, when tested comprising: voltage source means for the control apparatus; logic means responsive to the state of energization of the load connected across the power source means to a common point and including a voltage responsive switch having an output circuit; timing means having a timing junction and an output and including a timing capacitor connected to the output circuit of the logic means, an output signal from the logic means preventing actuation of the timing means; output detector switch means coupled to the timing output and having an on-off voltage output; means to feed back the detector switch output to the timing output to lock the detector switch on once it turns on; and condition responsive switch means having open and closed operating modes coupled between the timing junction and the common point, any charge on the capacitor being drained when the switch is in closed operating mode when the detector switch has no voltage output.
Claim 4
Dependent Claim
187 words
Control apparatus for testing the existence of a condition after a predetermined period has elapsed following the energization of a load for producing a voltage signal should the condition exist, when tested comprising: voltage source means for the control apparatus; logic means responsive to the state of energization of the load connected across the power source means to a common point and including a voltage responsive switch having an output circuit; timing means having a timing junction and an output and including a timing capacitor connected to the output circuit of the logic means, an output signal from the logic means preventing actuation of the timing means; output detector switch means coupled to the timing output and having an on-off voltage output; means to feed back the detector switch output to the timing output to lock the detector switch on once it turns on; and condition responsive switch means having open and closed operating modes coupled between the timing junction and the common point, any charge on the capacitor being drained when the switch is in closed operating mode when the detector switch has no voltage output.
Claim 5
Dependent Claim
33 words
Control apparatus according to claim 2 including means to feed back the detector switch means output to the input of the detector switch means to cause it to turn on with snap action.
Claim 6
Dependent Claim
91 words
Control apparatus according to claim 2 in which the detector switch means includes an NPN transistor having a base coupled to the timing junction, the NPN transistor having an emitter-collector circuit connected between the voltage source means and common through a resistor, and a PNP transistor whose base is connected to the collector of the NPN transistor, the emitter collector circuit of the PNP transistor connected between the voltage source and common through a resistor, the output voltage of the detector switch being taken at the collector of the PNP transistor.
Claim 7
Dependent Claim
25 words
Control apparatus according to claim 4 including an emitter follower transistor coupled between the timing means and the detector switch means to match impedance therebetween.
Claim 8
Dependent Claim
153 words
Control apparatus for producing an output only after a predetermined period of time comprising: regulated voltage source means; timing means including a resistor-capacitor combination coupled across the voltage source means and a common and having a timing junction; detector switch means comprising an NPN transistor having a base comprising the input of the detector switch means coupled to the timing junction, the transistor having an emitter-collector circuit connected between the voltage source means and common through a resistor; a PNP transistor whose base is connected to the collector of the NPN transistor, the emitter-collector circuit of the PNP transistor connected between the voltage source and common through a resistor, the output voltage of the detector switch being taken at the collector of the PNP transistor; and means to feed back the detector switch means output voltage to the input of the detector switch means to cause it to turn on with snap action.
Claim 9
Dependent Claim
153 words
Control apparatus for producing an output only after a predetermined period of time comprising: regulated voltage source means; timing means including a resistor-capacitor combination coupled across the voltage source means and a common and having a timing junction; detector switch means comprising an NPN transistor having a base comprising the input of the detector switch means coupled to the timing junction, the transistor having an emitter-collector circuit connected between the voltage source means and common through a resistor; a PNP transistor whose base is connected to the collector of the NPN transistor, the emitter-collector circuit of the PNP transistor connected between the voltage source and common through a resistor, the output voltage of the detector switch being taken at the collector of the PNP transistor; and means to feed back the detector switch means output voltage to the input of the detector switch means to cause it to turn on with snap action.
Claim 10
Dependent Claim
155 words
Control apparatus for producing an output only after a predetermined period of time comprising; regulated voltage source means; timing means including a resistor-capacitor combination coupled across the voltage source means and a common and having a timing junction; detector switch means comprising an NPN transistor having a base comprising the input of the detector switch means coupled to the timing junction, the transistor having an emitter-collector circuit connected between the voltage source means and common through a resistor; a PNP transistor whose base is connected to the collector of the NPN transistor, the emitter-collector circuit of the PNP transistor connected between the voltage source and common through a resistor, the output voltage of the detector switch being taken at the collector of the PNP transistor; and means to feed back the detector switch means output to the input of the detector switch means to lock the detector switch on once it produces an output voltage.
Claim 11
Dependent Claim
155 words
Control apparatus for producing an output only after a predetermined period of time comprising; regulated voltage source means; timing means including a resistor-capacitor combination coupled across the voltage source means and a common and having a timing junction; detector switch means comprising an NPN transistor having a base comprising the input of the detector switch means coupled to the timing junction, the transistor having an emitter-collector circuit connected between the voltage source means and common through a resistor; a PNP transistor whose base is connected to the collector of the NPN transistor, the emitter-collector circuit of the PNP transistor connected between the voltage source and common through a resistor, the output voltage of the detector switch being taken at the collector of the PNP transistor; and means to feed back the detector switch means output to the input of the detector switch means to lock the detector switch on once it produces an output voltage.
Claim 12
Dependent Claim
72 words
Control apparatus according to claim 2 in which the logic means includes two resistors connected to form a voltage divider and having a junction therebetween, the voltage responsive switch being a logic transistor whose base is connected to the junction of the voltage divider, the emitter-collector circuit of the logic transistor being coupled across the voltage source means and common, the collector of the logic transistor being coupled to the timing means.
Claim 13
Dependent Claim
36 words
Control apparatus according to claim 6 including a condition responsive switch means having open and closed operating modes coupled between the timing junction and common, the switch when closed adapted to drain charge from the capacitor.
Claim 14
Dependent Claim
50 words
Control apparatus according to claim 9 including means to feed back the detector switch means output voltage to the timing means output to lock the detector switch means on once it produces an output voltage, the detector switch means being locked on even when the condition responsive switch is closed.
Claim 15
Dependent Claim
15 words
Control apparatus according to claim 9 including reset contacts connected across the condition responsive switch.
Claim 16
Dependent Claim
93 words
Control apparatus according to claim 1 further including: a plurality of voltage dividers each of which includes a condition-responsive impedance element serially connected with a reference impedance element, each of the voltage dividers having an electrical junction between the condition-responsive and reference impedance element thereof; the voltage dividers being connected in parallel across the secondary winding source; and the input of the electronic element being coupled to each of the voltage divider junctions to control the conductivity of the output circuit, whereby the condition-responsive elements function to exercise control over the load device.
Claim 17
Dependent Claim
34 words
Control apparatus according to claim 3 in which the feed back means to produce snap action includes a resistor connected between the output of the detector means and input of the detector switch means.
Claim 18
Dependent Claim
34 words
Apparatus according to claim 2 in which the feed back means to lock on the detector switch includes a resistor and serially connected diode coupled between the detector switch junction and the timing output.
Claim 19
Dependent Claim
198 words
Control apparatus for testing the existence of a condition after a predetermined period has elapsed following the energization of a load for producing a voltage signal should the condition exist, when tested comprising: voltage source means for the control apparatus; logic means responsive to the state of energization of the load connected across the power source means to a common point and including a voltage responsive switch having an ouput circuit; timing means having a timing junction aNd including a timing capacitor connected to the output circuit of the logic means, an output signal from the logic means preventing actuation of the timing means; output detector switch means coupled to the timing junction and having an on-off voltage output and an input; means to feed back the detector switch output to the input of the detector switch means to lock the detector switch on once it turns on; and condition responsive sensor means having high and low resistance states connected to the voltage responsive switch of the logic means, the voltage responsive switch producing an output signal when the condition responsive sensor means is in one of its two resistance states to prevent actuation of the timing means.
Claim 20
Dependent Claim
198 words
Control apparatus for testing the existence of a condition after a predetermined period has elapsed following the energization of a load for producing a voltage signal should the condition exist, when tested comprising: voltage source means for the control apparatus; logic means responsive to the state of energization of the load connected across the power source means to a common point and including a voltage responsive switch having an ouput circuit; timing means having a timing junction aNd including a timing capacitor connected to the output circuit of the logic means, an output signal from the logic means preventing actuation of the timing means; output detector switch means coupled to the timing junction and having an on-off voltage output and an input; means to feed back the detector switch output to the input of the detector switch means to lock the detector switch on once it turns on; and condition responsive sensor means having high and low resistance states connected to the voltage responsive switch of the logic means, the voltage responsive switch producing an output signal when the condition responsive sensor means is in one of its two resistance states to prevent actuation of the timing means.
Claim 21
Dependent Claim
17 words
Control apparatus according to claim 15 in which the condition responsive sensor means includes a PTC thermistor.
Claim 22
Dependent Claim
36 words
Control apparatus according to claim 7 including a condition responsive switch means having open and closed operating modes connected between the timing junction and common, the switch when closed adapted to drain charge from the capacitor
Claim 23
Dependent Claim
53 words
Control apparatus according to claim 17 including means to feed back the detector switch means output voltage to the input of the detector switch means to lock the detector switch means on once it produces an output voltage, the detector switch means being locked on even when the condition responsive switch is closed.
Claim 24
Dependent Claim
15 words
Control apparatus according to claim 17 including reset contacts connected across the condition responsive switch.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |