US3648437A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic scr precipitator control
Assignee: Beazer East Inc
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Filing: 1969-07-23
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Granted: 1972-03-14
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Expires: 1989-07-23
Abstract
Abstract An automatic precipitator energization control circuit wherein precipitator voltage is rapidly reduced to zero for an independently selective period of duration upon the occurrence of each spark or flashover in the precipitator and gradually increased to a voltage level determined with reference to the voltage level of the precipitator at the time the spark occurred. The deleterious effects of multiple sparks or spark bursts are eliminated, a soft start is assured, and true r.m.s. current is sensed to provide a current limit to override the spark control circuitry to limit the input power to the unit and to clear a short circuit condition in the precipitator from dirt buildup or the like.
Inventors
- 👤 Richard J Bridges
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:35
CPC Classifications
B; B03; B03C; B03C3/00; B03C3/34; B03C3/66; B03C3/68; Y; Y10; Y10S; Y10S323/00; Y10S323/903
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
215 words
A precipitator control circuit comprising, controllable gate means operable for controlling electrical power to a precipitator, spark sensing means connected for sensing the voltage drop of electrical power supplied through said gate means to a precipitator being controlled upon the occurrence of a flashover, wave forming means operable to form at least one control pulse of predetermined magnitude and duration in response to a flashover sensed by said spark sensing means, fast response means connected to receive and store energy of said formed control pulse and discharge the same at a predetermined fast rate, variable impedance means operable to control the amount of energy of said formed control pulse to be stored in said fast response means, slow response means connected to receive and store energy of said formed control pulse and discharge the same at a predetermined slower rate, control means responsive to the discharge of said fast response means to correspondingly regulate said gate means to substantially cut off the electrical power supplied therethrough to a precipitator being controlled, said control means also being responsive to the discharge of said slow response means to regulate said gate means by correspondingly controlling the rise time of electrical power supplied therethrough to operating levels subsequent to cutoff thereof in response to said fast response discharge.
Claim 2
Dependent Claim
215 words
A precipitator control circuit comprising, controllable gate means operable for controlling electrical power to a precipitator, spark sensing means connected for sensing the voltage drop of electrical power supplied through said gate means to a precipitator being controlled upon the occurrence of a flashover, wave forming means operable to form at least one control pulse of predetermined magnitude and duration in response to a flashover sensed by said spark sensing means, fast response means connected to receive and store energy of said formed control pulse and discharge the same at a predetermined fast rate, variable impedance means operable to control the amount of energy of said formed control pulse to be stored in said fast response means, slow response means connected to receive and store energy of said formed control pulse and discharge the same at a predetermined slower rate, control means responsive to the discharge of said fast response means to correspondingly regulate said gate means to substantially cut off the electrical power supplied therethrough to a precipitator being controlled, said control means also being responsive to the discharge of said slow response means to regulate said gate means by correspondingly controlling the rise time of electrical power supplied therethrough to operating levels subsequent to cutoff thereof in response to said fast response discharge.
Claim 3
Dependent Claim
64 words
The precipitator control circuit of claim 1 including a current sensing means operable for sensing a current rise in excess of a predetermined operational level of electrical power supplied through said gate means and to form a current control signal of corresponding magnitude and duration and apply the same to said slow response means to correspondingly reduce power being supplied through said gate means.
Claim 4
Dependent Claim
37 words
The precipitator control circuit of claim 2 wherein said current control signal is regulated by said current sensing means to be of sufficient magnitude to initially reduce power being supplied through said gate means to substantially zero.
Claim 5
Dependent Claim
19 words
The precipitator control circuit of claim 2 wherein said current sensing means senses the r.m.s. value of said current.
Claim 6
Dependent Claim
40 words
The precipitator control circuit of claim 4 wherein said current sensing means includes a variable current limit adjust to regulate the magnitude of the sensed current and an incandescent bulb-photodiode combination to measure the r.m.s. value of the sensed current.
Claim 7
Dependent Claim
30 words
The precipitator control circuit of claim 1 wherein said fast response means and slow response means primarily consist of RC networks connected to a common input for said control means.
Claim 8
Dependent Claim
37 words
The precipitator control circuit of claim 6 wherein said slow response RC network is provided with a variable impedance input to permit adjustment of the amount of energy of said formed control pulse to be stored therein.
Claim 9
Dependent Claim
25 words
The precipitator control circuit of claim 7 characterized by variable impedance means in said RC Networks to permit variation of the RC discharge time constant.
Claim 10
Dependent Claim
16 words
The precipitator control circuit of claim 1 wherein said wave forming means includes a monostable multivibrator.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-14 | 1975-09-13 | 1976-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-14 | 1979-09-13 | 1980-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-14 | 1983-09-13 | 1984-03-14 | $7700.00 | Window Closed / Lapsed |