Patent US3783368A successfully refreshed from Google Patents.
US3783368A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and circuit for the approximately continuous control by means of an electric on-off control
Assignee: Heberlein and Co AG
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Filing: 1972-04-03
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Granted: 1974-01-01
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Expires: 1992-04-03
Abstract
Abstract Continuous control of an on-off-type A-C powered regulating system incorporating a thyristor switch is obtained by varying the switch activation threshold voltage repetitively at a rate the period of which is several times greater than the period of the supply voltage.
Inventors
- 👤 P Dosch
- 👤 D Dorsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:58
CPC Classifications
H; H02; H02M; H02M1/00; H02M1/08; H02M1/083
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
139 words
A method of obtaining continuous control of an A-C powered electrical circuit in which a switch is provided to control A-C current flow through a control element in response to trigger voltages above a threshold voltage level, said method comprising the steps of connecting said control element in series with an AC source and the input nodes of a full wave rectifier bridge, and connecting said switch in series with the output nodes of said bridge, generating trigger voltages having amplitudes which vary in proportion to a sensed deviation of said control element, varying said threshold level between a minimum and maximum level at a constant rate the period of which is several times greater than the period of applied A-C voltage variation, and applying only said trigger voltages which are larger than said threshold level to said switch.
Claim 2
Independent Claim
139 words
A method of obtaining continuous control of an A-C powered electrical circuit in which a switch is provided to control A-C current flow through a control element in response to trigger voltages above a threshold voltage level, said method comprising the steps of connecting said control element in series with an AC source and the input nodes of a full wave rectifier bridge, and connecting said switch in series with the output nodes of said bridge, generating trigger voltages having amplitudes which vary in proportion to a sensed deviation of said control element, varying said threshold level between a minimum and maximum level at a constant rate the period of which is several times greater than the period of applied A-C voltage variation, and applying only said trigger voltages which are larger than said threshold level to said switch.
Claim 3
Dependent Claim
17 words
A method according to claim 1, wherein said threshold level is varied according to a sawtooth pattern.
Claim 4
Dependent Claim
24 words
A method according to claim 1, wherein said trigger voltages are generated upon each reversal of voltage direction produced by applied A-C electricl power.
Claim 5
Dependent Claim
59 words
A method according to claim 1, wherein said step of applying only said trigger vOltages which are larger than said threshold level to said switch is performed by electrically summing the trigger voltages and a generator voltage which varies alternately at a rate the period of which is several times greater than the period of applied A-C voltage variation.
Claim 6
Independent Claim
162 words
A system for obtaining continuous control of an A-C powered electrical circuit in which a switch is provided to control current flow through a control element in response to trigger voltages above a threshold voltage level, said system comprising a full wave rectifier bridge having a pair of input nodes and a pair of output nodes, and having said control element connected in series with an A-C source across said input nodes and said switch connected across said output nodes, means for generating trigger voltages having amplitudes which vary in proportion to a sensed deviation of said control element, means for generating a threshold voltage which varies between a minimum and maximum level at a constant rate the period of which is several times greater than the period of applied A-C voltage variations, and comparison means connected to said trigger voltage and threshold voltage generating means for applying only said trigger voltages which are larger than said threshold level to said switch.
Claim 7
Independent Claim
162 words
A system for obtaining continuous control of an A-C powered electrical circuit in which a switch is provided to control current flow through a control element in response to trigger voltages above a threshold voltage level, said system comprising a full wave rectifier bridge having a pair of input nodes and a pair of output nodes, and having said control element connected in series with an A-C source across said input nodes and said switch connected across said output nodes, means for generating trigger voltages having amplitudes which vary in proportion to a sensed deviation of said control element, means for generating a threshold voltage which varies between a minimum and maximum level at a constant rate the period of which is several times greater than the period of applied A-C voltage variations, and comparison means connected to said trigger voltage and threshold voltage generating means for applying only said trigger voltages which are larger than said threshold level to said switch.
Claim 8
Dependent Claim
19 words
A system according to claim 5, wherein said means for generating said threshold voltage comprises a sawtooth voltage generator.
Claim 9
Dependent Claim
33 words
A system according to claim 5, wherein said means for generating trigger voltages comprises an impulse generator operative to generate a voltage impulse in response to each reversal of applied A-C electrical power.
Claim 10
Dependent Claim
34 words
A system according to claim 7, wherein said means for generating trigger voltages further comprises means for controlling the amplitude of each voltage impulse in response to a sensed deviation of said control element.
Claim 11
Dependent Claim
21 words
A system according to claim 5, wherein said switch is a thyristor having a control electrode coupled to said comparison means.
Claim 12
Dependent Claim
46 words
A system according to claim 5, wherein said means for generating trigger voltages comprises an impulse generator operative to generate a voltage impulse in response to each reversal of applied A-C electrical power, and variable coupling means for coupling said voltage impulses to said comparison means.
Claim 13
Dependent Claim
40 words
A system according to claim 5, wherein said comparison means comprises a transistor amplifier connected such that its voltage supply is received from said threshold voltage generating means and its signal input is received from said trigger voltage generating means.
Claim 14
Dependent Claim
55 words
A system according to claim 5, further comprising a voltage supply connected in common to said means for generating trigger voltages and said threshold voltage generating means so that, upon variations in said common voltage supply, mutually compensating voltage changes occur in said means for generating trigger voltages and in said threshold voltage generating means.
Claim 15
Dependent Claim
89 words
A method according to claim 1, wherein said step of generating trigger voltages having amplitudes which vary in proportion to a sensed deviation of said control element is performed by generating a trigger pulse upon each reversal of voltage direction of said A-C power, applying said trigger pulses to the primary of a transformer, and producing the said trigger voltages at the secondary of the transformer by varying the coupling between the transformer primary and secondary of the transformer in proportion to a sensed deviation of said control element.
Claim 16
Dependent Claim
26 words
A method according to claim 13 further comprising the step of supplying power for generating said trigger voltages and threshold voltage from a common power supply.
Claim 17
Independent Claim
181 words
A system for continuously controlling the quantity of A-C power applied to a control element comprising: a full wave rectifier bridge having a pair of A-C inputs and a pair of D-C outputs; a control element for connection in series with said A-C inputs across an A-C source; an electronic switch having a paiR of principal conducting electrodes and a control electrode, and having its principal conducting electrodes connected across said D-C outputs; means for generating trigger voltages at twice the frequency of said A-C source, said trigger voltages having amplitudes which vary in proportion to a sensed deviation of said control element; means for generating a threshold voltage which varies between a minimum and maximum level at a constant rate the period of which is several times greater than the period of applied A-C voltage variations; and comparison means connected to said trigger voltage and threshold voltage generating means for applying only said trigger voltages which are larger than said threshold level to said control electrode for actuating said switch to provide an A-C current path through said control element.
Claim 18
Independent Claim
181 words
A system for continuously controlling the quantity of A-C power applied to a control element comprising: a full wave rectifier bridge having a pair of A-C inputs and a pair of D-C outputs; a control element for connection in series with said A-C inputs across an A-C source; an electronic switch having a paiR of principal conducting electrodes and a control electrode, and having its principal conducting electrodes connected across said D-C outputs; means for generating trigger voltages at twice the frequency of said A-C source, said trigger voltages having amplitudes which vary in proportion to a sensed deviation of said control element; means for generating a threshold voltage which varies between a minimum and maximum level at a constant rate the period of which is several times greater than the period of applied A-C voltage variations; and comparison means connected to said trigger voltage and threshold voltage generating means for applying only said trigger voltages which are larger than said threshold level to said control electrode for actuating said switch to provide an A-C current path through said control element.
Claim 19
Dependent Claim
90 words
A system as set forth in claim 19, wherein said means for generating trigger voltages comprises an impulse generator connected across said D-C outputs and being operative to generate a voltage impulse in response to each reversal of applied A-C electrical power, and variable coupling means for coupling said voltage impulses to said comparison means, and wherein said comparison means comprises a transistor amplifier connected such that its voltage supply is received from said threshold voltage generating means, and its signal input is received from said trigger voltage generating means.
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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) | 1976-12-31 | 1977-07-02 | 1978-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-31 | 1981-07-02 | 1982-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-31 | 1985-07-02 | 1986-01-01 | $7700.00 | Window Closed / Lapsed |