Patent US4035599A successfully refreshed from Google Patents.
US4035599A
Expired / Lapsed
US
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Control system for non-resonant microwave dryers
Assignee: National Research Council Canada
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Filing: 1976-02-23
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Granted: 1977-07-12
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Expires: 1996-02-23
Abstract
Abstract The control system monitors the input power to and the output from the dryer applicator, and varies the input power to the applicator as a function of change in applicator efficiency and input power. The control system may consist of a first and a second circuit. The first circuit receives a signal P in .sbsb.1 from a first monitor and a signal P out .sbsb.1 from a second monitor. These signals are combined into an efficiency signal η 1 to which a reference efficiency signal -η o is added. An amplifier having a predetermined gain K amplifies the resulting signal to produce -K(η 1 -η o ). The second circuit adds the signals P in .sbsb.1 from the first monitor, -K(η 1 -η o ) from the first circuit and P in .sbsb.o, a signal representative of input power for a reference condition, to produce an output signal I in .sbsb.1 - [P in .sbsb.o + K(η 1 -η o )] which is coupled to the microwave source to control the input power to the applicator. The reference signal P in .sbsb.o may be generated by a voltage source as a function of transport speed of the load through the applicator.
Inventors
- 👤 Satish C. Kashyap
- 👤 Walter Wyslouzil
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:40
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/64; H05B6/78; H05B6/788; G; G05; G05D; G05D22/00; G05D22/02; H05B6/66; H05B6/68; H05B2206/00; H05B2206/04; H05B2206/046
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
116 words
A control system for a microwave dryer having an applicator for applying microwave energy to a load transported through said applicator and a controlled microwave source for feeding the applicator comprising: first means for monitoring the input power to said applicator and providing an output signal P in .sbsb.1 ; second means for monitoring the output power from said applicator and providing an output signal P out .sbsb.1 ; and third means connected between said first and second means and said microwave source to control the input power to said applicator as a function of change in the input power P in .sbsb.1 and in efficiency η 1 , where η.sub.1 = 1 - P.sub.out.sbsb.1 /P.sub.in.sbsb.1
Claim 2
Dependent Claim
116 words
A control system for a microwave dryer having an applicator for applying microwave energy to a load transported through said applicator and a controlled microwave source for feeding the applicator comprising: first means for monitoring the input power to said applicator and providing an output signal P in .sbsb.1 ; second means for monitoring the output power from said applicator and providing an output signal P out .sbsb.1 ; and third means connected between said first and second means and said microwave source to control the input power to said applicator as a function of change in the input power P in .sbsb.1 and in efficiency η 1 , where η.sub.1 = 1 - P.sub.out.sbsb.1 /P.sub.in.sbsb.1
Claim 3
Dependent Claim
104 words
A control system as claimed in claim 1 wherein said third means includes: first circuit means coupled to said first means and said second means for providing an output signal K(η 1 -η 0 ) where η 0 is the efficiency for a reference condition and K is a predetermined constant; and second circuit means coupled to said first circuit means and said first monitoring means for providing a control signal P in .sbsb.1 - [P in .sbsb.o + K(η 1 -η 0 )] to said microwave source, where P in .sbsb.o is a signal representing the applicator input power for a reference condition.
Claim 4
Dependent Claim
42 words
A control system as claimed in claim 2 wherein said second circuit means includes tachometer means for monitoring the transport speed of the load through said applicator, said tachometer means generating a signal -P in .sbsb.o as a function of transport speed.
Claim 5
Dependent Claim
103 words
A control system as claimed in claim 2 wherein said first circuit means includes: divider means having a first input coupled to said first monitoring means, and a second input coupled to said second monitoring means for providing an output η 1 ; a first reference voltage source for generating η 0 ; first adder means having a first input coupled to said divider means and a second input coupled to said first reference source for providing an output (η 1 -η 0 ); and amplifier means coupled to said first adder means for providing an output - K(η 1 -η 0 ).
Claim 6
Dependent Claim
79 words
A control system as claimed in claim 3 wherein said second circuit means includes: second reference voltage means for generating -P in .sbsb.o ; and second adder means having a first input coupled to said first monitoring means, a second input coupled to said amplifier means and a third input coupled to said second reference voltage means, the output of said second adder means being connected to said microwave source to provide a control signal to said microwave source.
Claim 7
Dependent Claim
43 words
A control system as claimed in claim 5 wherein said second reference voltage means includes: tachometer means for monitoring the transport speed of the load through the applicator, said tachometer means generating a signal -P in .sbsb.o as a function of transport speed.
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) | 1980-07-11 | 1981-01-10 | 1981-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-11 | 1985-01-10 | 1985-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-11 | 1989-01-10 | 1989-07-12 | $7700.00 | Window Closed / Lapsed |