US3802091A
Expired / Lapsed
US
⏱️ 0.0 years remaining
D.c. shutdown circuitry for i.c controlled dryer
Assignee: Whirlpool Corp
•
Filing: 1973-05-07
•
Granted: 1974-04-09
•
Expires: 1993-05-07
Abstract
Abstract In an integrated circuit controlled clothes dryer which includes a circuit for producing a reset pulse to initialize a memory storing a program of drying functions, D.C. shutdown circuitry is interposed between the integrated circuit chip and the power supply for the integrated circuit to quickly remove D.C. voltage from the integrated circuit at selected times so that a positive generation of the reset pulse may be obtained upon the reapplication of power to the integrated circuit. The D.C. power supply includes a capacitive filter which is isolated from the circuit and when power is removed so that upon the occurrence of a rapid succession of reapplications of power a smooth, well filtered D.C. is always available to the integrated circuit.
Inventors
- 👤 C Offutt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:48
CPC Classifications
D; D06; D06F; D06F34/00; D06F34/10; D06F2103/00; D06F2103/02; D06F2103/08; D06F2103/10; D06F2103/38; D06F2103/44
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
245 words
A dryer including a control comprising an integrated circuit having a memory storing a drying program and an internal pulse generating means for generating a pulse to initialize the memory, and a D.C. supply for the control, said D.C. supply comprising: a power transformer for connection to an A.C. power source; a first rectifier connected to said transformer and having first and second leads and operable to supply a D.C. voltage to said integrated circuit by way of said first and second leads; a first capacitor connected across said first and second leads to filter the supply of D.C. voltage; voltage regulator means including a transistor connected in circuit with said first and second leads and operable to remove the D.C. supply voltage from said integrated circuit and isolate said first capacitor; and a second rectifier connected to said transformer for supplying a supplemental rectified D.C. voltage; D.C. shutdown means connected to said second rectifier and to said voltage regulator means including a second capacitor connected to and charged by said second rectifier, and resistance means connecting said second capacitor to said voltage regulator means, said D.C. shutdown means operable within a predetermined interval in response to disconnection of the A.C. power source from said power transformer to cause said voltage regulator means to remove the D.C. voltage from said integrated circuit, said predetermined interval being sufficient to permit said internal pulse generating means to generate a pulse when the A.C. power source is reconnected.
Claim 2
Dependent Claim
245 words
A dryer including a control comprising an integrated circuit having a memory storing a drying program and an internal pulse generating means for generating a pulse to initialize the memory, and a D.C. supply for the control, said D.C. supply comprising: a power transformer for connection to an A.C. power source; a first rectifier connected to said transformer and having first and second leads and operable to supply a D.C. voltage to said integrated circuit by way of said first and second leads; a first capacitor connected across said first and second leads to filter the supply of D.C. voltage; voltage regulator means including a transistor connected in circuit with said first and second leads and operable to remove the D.C. supply voltage from said integrated circuit and isolate said first capacitor; and a second rectifier connected to said transformer for supplying a supplemental rectified D.C. voltage; D.C. shutdown means connected to said second rectifier and to said voltage regulator means including a second capacitor connected to and charged by said second rectifier, and resistance means connecting said second capacitor to said voltage regulator means, said D.C. shutdown means operable within a predetermined interval in response to disconnection of the A.C. power source from said power transformer to cause said voltage regulator means to remove the D.C. voltage from said integrated circuit, said predetermined interval being sufficient to permit said internal pulse generating means to generate a pulse when the A.C. power source is reconnected.
Claim 3
Dependent Claim
14 words
A dryer according to claim 1, wherein said supplemental supply means comprises a diode.
Claim 4
Dependent Claim
52 words
A dryer according to claim 1, wherein said voltage regulator means comprises a Zener diode connected between said transistor and one of said leads, and said resistance means comprises at least two serially connected resistors connected across said second capacitor and connected to the junction between said transistor and said Zener diode.
Claim 5
Dependent Claim
190 words
A dryer including a control comprising an integrated circuit having a memory storing a drying program and an internal pulse generating means for generating a pulse to initialize the memory, and a D.C. supply for said control, said D.C. supply comprising: first rectifier means for connection to an A.C. supply for deriving full wave rectified D.C. voltage; filter means connected to said first rectifier means for smoothing the full wave rectified D.C. voltage; second rectifier means for connection to the A.C. supply for deriving a half wave rectified voltage; a voltage regulator operable to connect and disconnect said filter means and said integrated circuit; and D.C. shutdown means connected in circuit between said second rectifier means and said voLtage regulator and including connection control means effective in response to connection of said second rectifier means to the A.C. supply to cause said voltage regulator to connect said integrated circuit to said filter means; and disconnection control means effective via said connection control means in response to disconnection of said second rectifier means from the A.C. supply to cause said voltage regulator to disconnect said integrated circuit from said filter means.
Claim 6
Dependent Claim
190 words
A dryer including a control comprising an integrated circuit having a memory storing a drying program and an internal pulse generating means for generating a pulse to initialize the memory, and a D.C. supply for said control, said D.C. supply comprising: first rectifier means for connection to an A.C. supply for deriving full wave rectified D.C. voltage; filter means connected to said first rectifier means for smoothing the full wave rectified D.C. voltage; second rectifier means for connection to the A.C. supply for deriving a half wave rectified voltage; a voltage regulator operable to connect and disconnect said filter means and said integrated circuit; and D.C. shutdown means connected in circuit between said second rectifier means and said voLtage regulator and including connection control means effective in response to connection of said second rectifier means to the A.C. supply to cause said voltage regulator to connect said integrated circuit to said filter means; and disconnection control means effective via said connection control means in response to disconnection of said second rectifier means from the A.C. supply to cause said voltage regulator to disconnect said integrated circuit from said filter means.
Claim 7
Dependent Claim
122 words
A dryer according to claim 4, wherein said voltage regulator comprises a transistor having a collector-emitter path connected between said filter means and said integrated circuit and a base, and a breakdown diode connected between said base and a reference potential; said connection control means comprises a voltage divider connected between said second rectifier means and said reference potential and including a tap connected to said base for supplying base current sufficient to sustain conduction of said transistor; and said disconnection control means comprises a capacitor connected across said voltage divider charged in response to the half wave rectified voltage and rapidly discharged via said voltage divider upon the loss of such voltage to rapidly remove the base current from said transistor.
Claim 8
Dependent Claim
46 words
A dryer according to claim 4, wherein said voltage regulator comprises a transistor having a control electrode and said connection control means comprises a voltage divider connected between said second rectifier means and said control electrode of said transistor to supply operating current to said transistor.
Claim 9
Dependent Claim
72 words
A dryer according to claim 4, wherein said voltage regulator comprises a transistor having a control electrode and said disconnection control means comprises a capacitor connected to and charged via said second rectifier means and connected to said control electrode of said transistor so that the discharging of said capacitor in response to an interruption in the A.C. supply rapidly exhausts the control current of said transistor and renders said transistor nonconductive.
Claim 10
Dependent Claim
208 words
In a clothes dryer circuit including an integrated circuit energized from a D.C. source the integrated circuit having a memory for storing a drying cycle program, means for ensuring application of smooth well filtered D.C. voltage to the integrated circuit during drying cycle operation together with rapid removal of the D.C. voltage from the integrated circuit on interruption of the power supply to the D.C. source to enable positive reset of the memory to a desired initial condition, comprising a transistor having its emitter connected to the integrated circuit, a filtered D.C. power supply network for the integrated circuit including a first capacitor connected to the collector of the transistor, a resistor-capacitor network including a second capacitor and having a relatively small RC time constant connected to the base of the transistor, the capacitance of said first capacitor being very large relative to the capacitance of said second capacitor whereby on interruption of a drying cycle program a charge may be stored on said first capacitor for a relatively long period of time to ensure availability of smooth D.C. for start-up of the integrated circuit, and the applied D.C. voltage is quickly removed from the integrated circuit due to the small RC time constant of the resistor-capacitor network.
Claim 11
Dependent Claim
208 words
In a clothes dryer circuit including an integrated circuit energized from a D.C. source the integrated circuit having a memory for storing a drying cycle program, means for ensuring application of smooth well filtered D.C. voltage to the integrated circuit during drying cycle operation together with rapid removal of the D.C. voltage from the integrated circuit on interruption of the power supply to the D.C. source to enable positive reset of the memory to a desired initial condition, comprising a transistor having its emitter connected to the integrated circuit, a filtered D.C. power supply network for the integrated circuit including a first capacitor connected to the collector of the transistor, a resistor-capacitor network including a second capacitor and having a relatively small RC time constant connected to the base of the transistor, the capacitance of said first capacitor being very large relative to the capacitance of said second capacitor whereby on interruption of a drying cycle program a charge may be stored on said first capacitor for a relatively long period of time to ensure availability of smooth D.C. for start-up of the integrated circuit, and the applied D.C. voltage is quickly removed from the integrated circuit due to the small RC time constant of the resistor-capacitor network.
Claim 12
Dependent Claim
25 words
In a clothes dryer circuit according to claim 8, wherein there is a voltage regulator means connected between the base of the transistor and ground.
References Cited (Backward Citations)
US3235786A
Cited
US3335361A
Cited
DE1800188A1
Cited
US3582713A
Cited
US3732442A
Cited
US3702030A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-08 | 1977-10-08 | 1978-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-08 | 1981-10-08 | 1982-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-08 | 1985-10-08 | 1986-04-09 | $7700.00 | Window Closed / Lapsed |