Patent US3721884A successfully refreshed from Google Patents.
US3721884A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Single transistor oscillator blasting device
Assignee: Bendix Corp
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Filing: 1971-11-23
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Granted: 1973-03-20
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Expires: 1991-11-23
Abstract
Abstract A blasting apparatus for firing an explosive bridge wire device or the like comprising a d.c. to d.c. converter circuit that utilizes only one transistor in the oscillator portion of the circuit to transfer energy from a battery to a storage capacitor which is automatically discharged upon reaching a predetermined energy level. The circuit also includes a single switch which in the OFF position discharges the storage capacitor and in the ON position connects the battery to the primary winding of the transformer to charge the storage capacitor.
Inventors
- 👤 K Thakore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:32
CPC Classifications
H; H02; H02M; H02M3/00; H02M3/22; H02M3/24; H02M3/28; H02M3/325; H02M3/335; H02M3/338; H02M3/3381; H03; H03K; H03K3/00; H03K3/02; H03K3/53
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
255 words
A blasting apparatus which comprises: a source of electrical energy; a transformer having a primary winding in electrical circuit relationship with said source, a control winding on the primary side of said transformer, and a secondary winding; first diode means and electrical energy storage means connected together in series across said secondary winding to store eNergy generated by the current flowing through said primary winding; and a solid state switch oscillator connected to said source and said primary and control winding of said transformer to periodically interrupt current flow from said source through said primary winding and thereby transfer energy to said energy storage means, said oscillator including: a transistor having collector and emitter terminals in series with said primary winding, and the base terminal connected directly to one end of said control winding, said transistor having alternate conductive and nonconductive intervals to periodically interrupt the current flow from said primary winding; a first voltage divider network connected in parallel with said source and connected across said transistor and said primary winding, said first voltage divider network comprising: a first and second series connected resistor connected across said primary winding and said transistor; a third resistor; and second diode means connected in series with said third resistor, said second diode means and said third resistor connected in parallel with said second resistor connected to the other end of said control winding; and third diode means connected directly across said transistor base and emitter terminals to direct current from said control winding in a predetermined manner.
Claim 2
Dependent Claim
255 words
A blasting apparatus which comprises: a source of electrical energy; a transformer having a primary winding in electrical circuit relationship with said source, a control winding on the primary side of said transformer, and a secondary winding; first diode means and electrical energy storage means connected together in series across said secondary winding to store eNergy generated by the current flowing through said primary winding; and a solid state switch oscillator connected to said source and said primary and control winding of said transformer to periodically interrupt current flow from said source through said primary winding and thereby transfer energy to said energy storage means, said oscillator including: a transistor having collector and emitter terminals in series with said primary winding, and the base terminal connected directly to one end of said control winding, said transistor having alternate conductive and nonconductive intervals to periodically interrupt the current flow from said primary winding; a first voltage divider network connected in parallel with said source and connected across said transistor and said primary winding, said first voltage divider network comprising: a first and second series connected resistor connected across said primary winding and said transistor; a third resistor; and second diode means connected in series with said third resistor, said second diode means and said third resistor connected in parallel with said second resistor connected to the other end of said control winding; and third diode means connected directly across said transistor base and emitter terminals to direct current from said control winding in a predetermined manner.
Claim 3
Dependent Claim
22 words
A blasting apparatus as recited in claim 1 including first switching means for disconnecting said source of electrical energy from said transformer.
Claim 4
Dependent Claim
81 words
The blasting apparatus as recited in claim 2 including a resistor in series with a second switching means and wherein a single switching means comprising said first and said second switching means is provided which connects said energy storage means in said transformer secondary circuit across said resistor in its OFF position and disconnects said resistor from across said energy storage means in its ON position whereby said energy storage means is discharged when said switch is in its OFF position.
Claim 5
Dependent Claim
79 words
The blasting apparatus as recited in claim 1 wherein said secondary circuit of said transformer includes a normally nonconducting gaseous conductor connected in series with a resistor, said gaseous conductor and resistor being connected in parallel with said energy storage means, said gaseous conductor operable to be conductive when said energy storage means reaches a predetermined energy level whereby the energy in said energy storage means may be discharged when said storage means reaches said predetermined energy storage level.
Claim 6
Dependent Claim
22 words
A blasting apparatus as recited in claim 4 including first switching means for disconnecting said source of electrical energy from said transformer.
Claim 7
Dependent Claim
80 words
The blasting apparatus as recited in claim 5 including a resistor in series with a second switching means and wherein a single switching means comprising said first and said second switching means is provided which connects said energy storage means in said transformer secondary circuit across said resistor in its OFF position and said resistor from across said energy storage means in its ON position whereby said energy storage means is discharged when said switch is in its OFF position.
Claim 8
Dependent Claim
19 words
The blasting apparatus as recited in claim 1 wherein said source of electrical energy is a direct current source.
Claim 9
Dependent Claim
78 words
The blasting apparatus as recited in claim 7 wherein said secondary circuit of said transformer includes a normally nonconducting gaseous conductor connected in series with a resistor, said gaseous conductor and resistor being connected in parallel with said energy storage means, said gaseous conductor operable to conductive when said energy storage means reaches a predetermined energy level whereby the energy in said energy storage means may be discharged when said storage means reaches said predetermined energy storage level.
Claim 10
Dependent Claim
22 words
A blasting apparatus as recited in claim 7 including first switching means for disconnecting said source of electrical energy from saId transformer.
Claim 11
Dependent Claim
81 words
The blasting apparatus as recited in claim 9 including a resistor in series with a second switching means and wherein a single switching means comprising said first and said second switching means is provided which connects said energy storage means in said transformer secondary circuit across said resistor in its OFF position and disconnects said resistor from across said energy storage means in its ON position whereby said energy storage means is discharged when said switch is in its OFF position.
Claim 12
Dependent Claim
31 words
The blasting apparatus as recited in claim 7 wherein the anodes of said second and third diodes are connected in circuit relationship with said negative end of said direct current source.
Claim 13
Dependent Claim
22 words
A blasting apparatus as recited in claim 11 including first switching means for disconnecting said source of electrical energy from said transformer.
Claim 14
Dependent Claim
81 words
The blasting apparatus as recited in claim 12 including a resistor in series with a second switching means and wherein a single switching means comprising said first and said second switching means is provided which connects said energy storage means in said transformer secondary circuit across said resistor in its OFF position and disconnects said resistor from across said energy storage means in its ON position whereby said energy storage means is discharged when said switch is in its OFF position.
Claim 15
Dependent Claim
79 words
The blasting apparatus as recited in claim 11 wherein said secondary circuit of said transformer includes a normally nonconducting gaseous conductor connected in series with a resistor, said gaseous conductor and resistor being connected in parallel with said energy storage means, said gaseous conductor operable to be conductive when said energy storage means reaches a predetermined energy level whereby the energy in said energy storage means may be discharged when said storage means reaches said predetermined energy storage level.
Claim 16
Dependent Claim
22 words
A blasting apparatus as recited in claim 14 including first switching means for disconnecting said source of electrical energy from said transformer.
Claim 17
Dependent Claim
81 words
The blasting apparatus as recited in claim 15 including a resistor in series with a second switching means and wherein a single switching means comprising said first and said second switching means is provided which connects said energy storage means in said transformer secondary circuit across said resistor in its OFF position and disconnects said resistor from across said energy storage means in its ON position whereby said energy storage means is discharged when said switch is in its OFF position.
Claim 18
Dependent Claim
19 words
The blasting apparatus as recited in claim 7 wherein said source of electrical energy is at least one battery.
Claim 19
Dependent Claim
79 words
The blasting apparatus as recited in claim 17 wherein said secondary circuit of said transformer includes a normally nonconducting gaseous conductor connected in series with a resistor, said gaseous conductor and resistor being connected in parallel with said energy storage means, said gaseous conductor operable to be conductive when said energy storage means reaches a predetermined energy level whereby the energy in said energy storage means may be discharged when said storage means reaches said predetermined energy storage level.
Claim 20
Dependent Claim
22 words
A blasting apparatus as recited in claim 18 including first switching means for disconnecting said source of electrical energy from said transformer.
Claim 21
Dependent Claim
81 words
The blasting apparatus as recited in claim 19 including a resistor in series with a second switching means and wherein a single switching means comprising said first and said second switching means is provided which connects said energy storage means in said transformer secondary circuit across said resistor in its OFF position and disconnects said resistor from across said energy storage means in its ON position whereby said energy storage means is discharged when said switch is in its OFF position.
Claim 22
Dependent Claim
19 words
The blasting apparatus recited in claim 17 including electrical energy storagE means connected across said first voltage divider means.
Claim 23
Dependent Claim
79 words
The blasting apparatus as recited in claim 21 wherein said secondary circuit of said transformer includes a normally nonconducting gaseous conductor connected in series with a resistor, said gaseous conductor and resistor being connected in parallel with said energy storage means, said gaseous conductor operable to be conductive when said energy storage means reaches a predetermined energy level whereby the energy in said energy storage means may be discharged when said storage means reaches said predetermined energy storage level.
Claim 24
Dependent Claim
22 words
A blasting apparatus as recited in claim 21 including first switching means for disconnecting said source of electrical energy from said transformer.
Claim 25
Dependent Claim
81 words
The blasting apparatus as recited in claim 23 including a resistor in series with a second switching means and wherein a single switching means comprising said first and said second switching means is provided which connects said energy storage means in said transformer secondary circuit across said resistor in its OFF position and disconnects said resistor from across said energy storage means in its ON position whereby said energy storage means is discharged when said switch is in its OFF position.
Claim 26
Dependent Claim
31 words
The blasting apparatus as recited in claim 21 wherein the anodes of said second and third diodes are connected in circuit relationship with said negative end of said direct current source.
Claim 27
Dependent Claim
22 words
A blasting apparatus as recited in claim 25 including first switching means for disconnecting said source of electrical energy from said transformer.
Claim 28
Dependent Claim
81 words
The blasting apparatus as recited in claim 26 including a resistor in series with a second switching means and wherein a single switching means comprising said first and said second switching means is provided which connects said energy storage means in said transformer secondary circuit across said resistor in its OFF position and disconnects said resistor from across said energy storage means in its ON position whereby said energy storage means is discharged when said switch is in its OFF position.
Claim 29
Dependent Claim
79 words
The blasting apparatus as recited in claim 25 wherein said secondary circuit of said transformer includes a normally nonconducting gaseous conductor connected in series with a resistor, said gaseous conductor and resistor being connected in parallel with said energy storage means, said gaseous conductor operable to be conductive when said energy storage means reaches a predetermined energy level whereby the energy in said energy storage means may be discharged when said storage means reaches said predetermined energy storage level.
Claim 30
Dependent Claim
22 words
A blasting apparatus as recited in claim 28 including first switching means for disconnecting said source of electrical energy from said transformer.
Claim 31
Dependent Claim
81 words
The blasting apparatus as recited in claim 29 including a resistor in series with a second switching means and wherein a single switching means comprising said first and said second switching means is provided which connects said energy storage means in said transformer secondary circuit across said resistor in its OFF position and disconnects said resistor from across said energy storage means in its ON position whereby said energy storage mean is discharged when said switch is in its OFF position.
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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) | 1976-03-19 | 1976-09-18 | 1977-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-19 | 1980-09-18 | 1981-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-19 | 1984-09-18 | 1985-03-20 | $7700.00 | Window Closed / Lapsed |