Patent US3733540A successfully refreshed from Google Patents.
US3733540A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Switching regulator sweep starting protection circuit
Assignee: Motorola Solutions Inc
•
Filing: 1972-02-03
•
Granted: 1973-05-15
•
Expires: 1992-02-03
Abstract
Abstract An overload protection system for a switching power supply includes a variable rate and variable pulse duration drive source for operating the switching transistor. Upon turn-on of the power supply, the switching transistor is driven with low repetition rate pulses having a predetermined time duration. The rate is gradually increased to a normal operating rate to minimize turnon transients. Load sensing circuitry is used in conjunction with the variable rate drive source to cause the drive source to operate at the low rate in the event that an overload is applied to the power supply, and to turn off the drive source if the overload persists. Circuitry for providing automatic reset following an overload is employed. A feedback circuit is used to vary the duration of the drive pulses to provide automatic voltage regulation.
Inventors
- 👤 G Hawkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:30
CPC Classifications
H; H02; H02M; H02M1/00; H02M1/36; H02H; H02H7/00; H02H7/10; H02H7/12; H02M3/00; H02M3/02; H02M3/04; H02M3/10; H02M3/145; H02M3/155; H02M3/156; Y; Y10; Y10S; Y10S323/00; Y10S323/901
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
193 words
A switching power supply control circuit for controlling the output voltage applied to an output point from a direct current source, including in combination, switch means connected to said source and to said output point for controlling the output voltage delivered to said output point by said source, said switch means having a conductive state for passing current to said load and a nonconductive blocking state, pulse control means for rendering said switch means conductive for a predetermined time duration connected to said switch means, said pulse control means being further connected to said output point and responsive to the voltage thereat for adjusting said time duration in a manner tending to maintain said output voltage substantially constant, rate control means for causing said switch means to be rendered alternately conductive and nonconductive at a predetermined rate connected to said pulse control means, said rate control means being further connected to said output point and responsive to the voltage thereat for causing said switch means to be alternately rendered conductive and nonconductive at a rate lower than said predetermined rate when the output voltage at said output point is below a predetermined level.
Claim 2
Dependent Claim
193 words
A switching power supply control circuit for controlling the output voltage applied to an output point from a direct current source, including in combination, switch means connected to said source and to said output point for controlling the output voltage delivered to said output point by said source, said switch means having a conductive state for passing current to said load and a nonconductive blocking state, pulse control means for rendering said switch means conductive for a predetermined time duration connected to said switch means, said pulse control means being further connected to said output point and responsive to the voltage thereat for adjusting said time duration in a manner tending to maintain said output voltage substantially constant, rate control means for causing said switch means to be rendered alternately conductive and nonconductive at a predetermined rate connected to said pulse control means, said rate control means being further connected to said output point and responsive to the voltage thereat for causing said switch means to be alternately rendered conductive and nonconductive at a rate lower than said predetermined rate when the output voltage at said output point is below a predetermined level.
Claim 3
Dependent Claim
105 words
A control circuit as recited in claim 1 further including protection means coupled to said pulse control means and to said output point, said protection means being responsive to said output voltage for maintaining said pulse control means operative to render said switch means conductive when said output voltage exceeds a predetermined value, and starting means coupled to said pulse control means for rendering said pulse control means operative for a predetermined time interval, said control means thereby being rendered operative by said starting means and maintained operative after said predetermined time interval by said protection means when the output voltage exceeds a predetermined level.
Claim 4
Dependent Claim
79 words
A switching power supply control circuit as recited in claim 1 wherein said pulse control means includes monostable means for applying pulses to said switch means connected to said switch means, said monostable means being further connected to said output point and responsive to the voltage thereat for altering the width of said pulses to increase the time duration thereof for increasing the time duration said switch is rendered conductive when said output voltage drops below a predetermined level.
Claim 5
Dependent Claim
65 words
A switching power supply control system as recited in claim 3 wherein said rate control means includes voltage controlled oscillator means connected to said monostable means for providing oscillations thereto, said oscillator means being connected to said output point and responsive to the voltage thereat for varying the frequency of said oscillations, said frequency being decreased in response to a decrease in said output voltage.
Claim 6
Dependent Claim
110 words
A starting and protection circuit for a power supply utilizing an electronic switch having conductive and nonconductIve states for controlling the output voltage applied to an output point of said supply, including in combination, means for periodically activating said switch to the conductive state at a predetermined periodic rate connected to said switch, means for controlling said rate connected to said activating means and to said output point, said rate control means being responsive to the voltage at said output point for decreasing said periodic rate in response to a decrease in said output voltage and for increasing said periodic rate in response to an increase in said output voltage.
Claim 7
Dependent Claim
110 words
A starting and protection circuit for a power supply utilizing an electronic switch having conductive and nonconductIve states for controlling the output voltage applied to an output point of said supply, including in combination, means for periodically activating said switch to the conductive state at a predetermined periodic rate connected to said switch, means for controlling said rate connected to said activating means and to said output point, said rate control means being responsive to the voltage at said output point for decreasing said periodic rate in response to a decrease in said output voltage and for increasing said periodic rate in response to an increase in said output voltage.
Claim 8
Dependent Claim
38 words
A starting and protection circuit as recited in claim 5 further including sensing means coupled to said activating means and to said output point for maintaining said activating means operative when said output voltage exceeds a predetermined level.
Claim 9
Dependent Claim
30 words
A starting and protection circuit as recited in claim 6 further including starting means coupled to said activating means for rendering said activating means operative for a predetermined time interval.
Claim 10
Dependent Claim
79 words
A starting and protection circuit as recited in claim 7 further including OR circuit means having inputs connected to said starting means and said sensing means, and an output connected to said activating means, said OR circuit means being responsive to said starting means for rendering said activating means operative for a predetermined time interval, and to said sensing means for maintaining said activating means operative after said predetermined time interval when said output voltage exceeds a predetermined level.
Claim 11
Dependent Claim
23 words
A starting and protection circuit as recited in claim 8 wherein said starting means includes means for repetitively rendering said activating means operative.
Claim 12
Dependent Claim
81 words
A starting and protection circuit as recited in claim 8 further including control means connected to said activating means and to said output point, said control means being responsive to the voltage at said output point for increasing the time during each period that said switch is maintained conductive in response to a decrease in the output voltage and for decreasing the time during each period that said switch is maintained conductive in response to an increase in the output voltage.
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) | 1976-05-14 | 1976-11-13 | 1977-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-14 | 1980-11-13 | 1981-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-14 | 1984-11-13 | 1985-05-15 | $7700.00 | Window Closed / Lapsed |