US3636368A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transfer switch and generator control means and new and improved method of operation thereof
Assignee: Onan Eastern Corp
•
Filing: 1970-06-29
•
Granted: 1972-01-18
•
Expires: 1990-06-29
Abstract
Abstract New and improved transfer switch and generator control means are provided and take the form of a substantially solid state electronic circuit which comprises operatively associated line voltage sensor means, circuit operating signal generating means, timer means to provide a readily adjustable time delay prior to retransfer to normal line voltage, timer means to provide a readily adjustable time delay prior to generator drive-engine shutdown, timer means to provide a readily adjustable time delay prior to generator drive-engine start, load transfer control means, retransfer to line voltage control means, readily adjustable generator output voltage sensor means and line voltage failure simulation test switch means, respectively. The transfer switch and generator control means are operable, upon a fall in line voltage below a predetermined minimum level thereof, to energize emergency generator means after the expiration of an adjustable time delay and transfer the load thereto as soon as the output from said emergency generator means has come up to a predetermined minimum level thereof. Upon the return of the line voltage to said predetermined minimum level thereof, the transfer switch and generator control means are operable, following an adjustable time delay, to retransfer the load to said line voltage and, following another adjustable time delay, to deenergize said emergency generator means.
Inventors
- 👤 Joseph B Sia
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 02:13
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/24; H02H3/253; H02J; H02J9/00; H02J9/04; H02J9/06; H02J9/066
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
162 words
In automatic transfer switch and generator control means for maintaining the powering of a load in the event of line voltage failure which include means to automatically commence operation of a generator and transfer the load thereto upon a drop in said live voltage below a predetermined minimum level thereof, and means to retransfer the load to said line voltage and discontinue operation of said generator upon the return of said line voltage to said predetermined minimum level thereof, the improvements comprising, line voltage sensor means, means to apply said line voltage thereto, said line voltage sensor means being operable to provide an output voltage of predetermined level in response to a drop in said line voltage below said predetermined minimum level thereof, switch means responsive to said output voltage and operable to control the reenergization of said generator and the transfer of the load thereto, and means to apply said output voltage to said switch means to control the operation thereof.
Claim 2
Dependent Claim
162 words
In automatic transfer switch and generator control means for maintaining the powering of a load in the event of line voltage failure which include means to automatically commence operation of a generator and transfer the load thereto upon a drop in said live voltage below a predetermined minimum level thereof, and means to retransfer the load to said line voltage and discontinue operation of said generator upon the return of said line voltage to said predetermined minimum level thereof, the improvements comprising, line voltage sensor means, means to apply said line voltage thereto, said line voltage sensor means being operable to provide an output voltage of predetermined level in response to a drop in said line voltage below said predetermined minimum level thereof, switch means responsive to said output voltage and operable to control the reenergization of said generator and the transfer of the load thereto, and means to apply said output voltage to said switch means to control the operation thereof.
Claim 3
Dependent Claim
58 words
Automatic transfer switch and generator control means as in claim 1 further comprising, means to adjust the level of said output voltage provided by said voltage senSor means in response to said line voltage to thereby enable the adjustment of the level of said line voltage which will be operable to provide said output voltage of predetermined level.
Claim 4
Dependent Claim
35 words
Automatic transfer switch and generator control means as in claim 2 wherein, said line voltage is of multiphase configuration, and said line voltage sensor means comprise means to sense each leg of said line voltage.
Claim 5
Dependent Claim
71 words
Automatic transfer switch and generator control means as in claim 3 wherein, said line voltage sensor means comprise a plurality of stepdown transformers, there being one transformer for each leg of said line voltage, means to respectively apply said line voltage legs to the primary windings of said transformers, and series-connected bridge circuits which are respectively connected to the transformer secondary windings to provide said line voltage sensor means output voltage.
Claim 6
Dependent Claim
22 words
Automatic transfer switch and generator control means as in claim 4 wherein, each of said bridge circuits is an SCR bridge circuit.
Claim 7
Dependent Claim
34 words
Automatic transfer switch and generator control means as in claim 2 wherein, said adjustment means comprise an adjustable resistor, and means to apply said line voltage sensor means output voltage to said adjustable resistor.
Claim 8
Dependent Claim
40 words
Automatic transfer switch and generator control means as in claim 5 wherein, said adjustment means comprise an adjustable resistor, and means to apply said line voltage sensor means output voltage from said series-connected SCR bridge circuits to said adjustable resistor.
Claim 9
Dependent Claim
131 words
In automatic transfer switch and generator control means as in claim 2 wherein, said means to sense line voltage and automatically commence operation of said generator and transfer the load thereto upon drop in said line voltage below a predetermined minimum level thereof comprise, line voltage sensor means operable to provide an output voltage of predetermined level in response to said line voltage being at said predetermined minimum level thereof, and operating signal generating means including said switch means which are operable in response to said line voltage sensor means output voltage of predetermined level to in turn provide an operating voltage signal, and which are further operable in response to a line voltage sensor means output voltage which is below said predetermined level to provide a different operating voltage signal.
Claim 10
Dependent Claim
41 words
Automatic transfer switch and generator control means as in claim 8 wherein, said switch means comprise fast-acting trigger circuit means which are turned ''''off'''' only when said line voltage sensor means output voltage is at or above said predetermined level thereof.
Claim 11
Dependent Claim
45 words
Automatic transfer switch and generator control means as in claim 9 wherein, said fast-acting trigger circuit means comprise first and second transistors connected in common emitter configuration, and means to apply said line voltage sensor means output voltage to the base of said first transistor.
Claim 12
Dependent Claim
108 words
Automatic transfer switch and generator control means as in claim 8 wherein, said means to sense line voltage and automatically commence operation of a generator and transfer the load thereto upon drop in said line voltage below a predetermined minimum level thereof comprise, generator energization control means, timer means operatively associated with said generator energization control means, and means to apply said operating voltage signals to said timer means, said timer means being effective in response to the application of said different operating voltage signal thereto to provide a predetermined time delay and, at the expiration thereof, to operate said generator energization control means to commence generator operation.
Claim 13
Dependent Claim
28 words
Automatic transfer switch and generator control means as in claim 11 wherein, said timer means comprise means to adjust the time delay provided thereby prior to generator energization.
Claim 14
Dependent Claim
75 words
Automatic transfer switch and generator control means as in claim 11 wherein, said timer means comprise a unijunction transistor which must be triggered prior to generator energization, and capacitor means operatively connected in the emitter circuit of said unijunction transistor and operable to delay the triggering of the latter until said capacitor means have been charged in response to said different operating voltage signal to discharge and provide the requisite unijunction transistor peak point voltage.
Claim 15
Dependent Claim
28 words
Automatic transfer switch and generator control means as in claim 13 wherein, said timer means comprise means to adjust the time delay provided thereby prior to generator energization.
Claim 16
Dependent Claim
52 words
Automatic transfer switch and generator control means as in claim 14 wherein, said means to adjust said time delay provided by said timer means comprise an adjustable resistor connected in series with said capacitor means and operable to adjust the charging time of the latter and to accordingly adjust said time delay.
Claim 17
Dependent Claim
96 words
Automatic transfer switch and generator control means as in claim 1 wherein, said means to sense line voltage and automatically commence operation of said generator and transfer the load thereto upon drop in said line voltage below said predetermined minimum level thereof further comprise, generator output voltage sensor means and operatively associated load transfer control means, said generator output voltage sensor means being operable to sense said generator output voltage and delay the operation of said transfer control means until such time as said generator output voltage has come up to a predetermined minimum level thereof.
Claim 18
Dependent Claim
135 words
Automatic transfer switch and generator control means as in claim 16 wherein, said generator output voltage sensor means comprise a stepdown transformer, means to apply said generator output voltage to the primary winding of said transformer to induce a control voltage in the secondary winding of said transformer, fast-acting trigger circuit means, means to apply said control voltage to said trigger circuit means, said trigger circuit means being turned ''''on'''' only when said control voltage assumes a predetermined minimum level thereof in response to said generator output voltage having come up to said predetermined minimum level thereof, and means connecting said fast-acting trigger circuit with said transfer control means in such manner that the latter will be operative to transfer the load to said generator output voltage only when said trigger circuit is turned ''''on.''''
Claim 19
Dependent Claim
62 words
Automatic transfer switch and generator control means as in claim 17 wherein, said generator output voltage sensor means comprise means to adjust the level of said control voltage provided in response to said generator output voltage to thereby enable the adjustment of the level of said generator output voltage which will be operative to provide said control voltage of predetermined minimum level.
Claim 20
Dependent Claim
38 words
Automatic transfer switch and generator control means as in claim 18 wherein, said control voltage adjustment means comprise an adjustable resistor, and means to apply the control voltage thereto prior to the application thereof to said trigger circuit.
Claim 21
Dependent Claim
41 words
Automatic transfer switch and generator control means as in claim 19 wherein, said fast-acting trigger circuit means comprise first and second transistors connected in common emitter configuration, and means to apply said control voltage to the base of said first transistor.
Claim 22
Dependent Claim
48 words
Automatic transfer switch and generator control means as in claim 17 wherein, said load transfer control means comprise solid-state relay means operatively associated with said fast-acting trigger circuit means and operable to be ''''closed'''' to effect load transfer only in response to the turning ''''on'''' of the latter.
Claim 23
Dependent Claim
48 words
Automatic transfer switch and generator control means as in claim 19 wherein, said load transfer control means comprise solid-state relay means operatively associated with said fast-acting trigger circuit means and operable to be ''''closed'''' to effect load transfer Only in response to the turning ''''on'''' of the latter.
Claim 24
Dependent Claim
129 words
Automatic transfer switch and generator control means as in claim 8 wherein, said means to retransfer the load to said line voltage and discontinue operation of said generator upon the return of said line voltage to said predetermined minimum level thereof comprise, load retransfer control means, retransfer timer means operatively associated with said load retransfer control means, means to apply said operating voltage signals to said retransfer timer means, said retransfer timer means being effective in response to the application of said operating voltage signal thereto, attendant the return of said line voltage to said predetermined minimum level thereof, to provide a predetermined time delay and, at the expiration thereof, to provide a signal to operate said load retransfer control means to retransfer the load to said line voltage.
Claim 25
Dependent Claim
130 words
Automatic transfer switch and generator control means as in claim 17 wherein, said retransfer timer means comprise first and second unijunction transistors, said first unijunction transistor being effective to prevent operation of said load retransfer control means until the former is triggered, said second unijunction transistor being operable to be triggered in response to said operating voltage signal to apply pulses to a base of said first unijunction transistor to reduce the minimum peak current of the latter, and capacitor means operatively connected in the emitter circuit of said first unijunction transistor and operable to delay the triggering of the latter until said capacitor means have been charged in response to said operating voltage signal to discharge and provide the peak point voltage required to trigger said first unijunction transistor.
Claim 26
Dependent Claim
29 words
Automatic transfer switch and generator control means as in claim 23 wherein, said retransfer timer means further comprise means to adjust the time delay provided by said timer means.
Claim 27
Dependent Claim
29 words
Automatic transfer switch and generator control means as in claim 24 wherein, said retransfer timer means further comprise means to adjust the time delay provided by said timer means.
Claim 28
Dependent Claim
45 words
Automatic transfer switch and generator control means as in claim 26 wherein, said time delay adjustment means comprise variable resistance means connected in series with said capacitor means and operable to adjust the charging time of the latter and to accordingly adjust said time delay.
Claim 29
Dependent Claim
48 words
Automatic transfer switch and generator control means as in claim 23 wherein, said load retransfer control means comprise solid-state relay means operatively associated with said retransfer timer means and operable to be ''''closed'''' to effect load retransfer only in response to said signal from said retransfer timer means.
Claim 30
Dependent Claim
48 words
Automatic transfer switch and generator control means as in claim 27 wherein, said load retransfer control means comprise solid-state relay means operatively associated with said retransfer timer means and operable to be ''''closed'''' to effect load retransfer only in response to said signal from said retransfer timer means.
Claim 31
Dependent Claim
129 words
Automatic transfer switch and generator control means as in claim 11 wherein, said means to retransfer the load to said line voltage and discontinue operation of said generator upon the return of said line voltage to said predetermined minimum level thereof comprise, load retransfer control means, retransfer timer means operatively associated with said load retransfer control means, means to apply said operating voltage signals to said retransfer timer means, said retransfer timer means being effective in response to the application of said operating voltage signal thereto, attendant the return of said line voltage to said predetermined minimum level thereof, to provide a predetermined time delay and, at the expiration thereof, to provide a signal to operate said load retransfer control means to retransfer the load to said line voltage.
Claim 32
Dependent Claim
116 words
Automatic transfer switch and generator contRol means as in claim 30 wherein, said means to retransfer the load to said line voltage and discontinue operation of said generator upon the return of said line voltage to said predetermined minimum level thereof comprise, generator shutdown timer means operatively associated with said generator energization control means and with said retransfer timer means, means to apply said signal from said retransfer timer means to said generator shutdown timer means, said generator shutdown timer means being effective in response to the application of said signal thereto to provide a predetermined time delay and, at the expiration thereof, to operate said generator energization control means to discontinue operation of said generator.
Claim 33
Dependent Claim
140 words
Automatic transfer switch and generator control means as in claim 31 wherein, said generator shutdown timer means comprise first and second unijunction transistors, said first unijunction transistor being effective to prevent operation of said generator energization control means to discontinue operation of said generator until the same is triggered, said second unijunction transistor being operable in response to said signal from said retransfer timer means to be triggered to apply pulses to a base of said first unijunction transistor to reduce the minimum peak current of the latter, and capacitor means operatively connected in the emitter circuit of said first unijunction transistor and operable to delay the triggering thereof until said capacitor means have been charged in response to said retransfer timer means signal to discharge and provide the peak point voltage required for triggering of said first unijunction transistor.
Claim 34
Dependent Claim
27 words
Automatic transfer switch and generator control means as in claim 31 wherein, said generator shutdown timer means further comprise means to adjust the time delay provided thereby.
Claim 35
Dependent Claim
27 words
Automatic transfer switch and generator control means as in claim 32 wherein, said generator shutdown timer means further comprise means to adjust the time delay provided thereby.
Claim 36
Dependent Claim
43 words
Automatic transfer switch and generator control means as in claim 34 wherein, said time delay adjustment means comprise variable resistance means connected in series with said capacitor means and operable to adjust the charging time thereof and to accordingly adjust said time delay.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-17 | 1975-07-19 | 1976-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-17 | 1979-07-19 | 1980-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-17 | 1983-07-19 | 1984-01-18 | $7700.00 | Window Closed / Lapsed |