US3921034A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stroboscopic device with electric shock preventive circuit
Assignee: Canon Inc
•
Filing: 1974-12-23
•
Granted: 1975-11-18
•
Expires: 1994-12-23
Abstract
Abstract In a stroboscopic device of the type including a trigger circuit which is charged by a power source, a trigger circuit for flashing a flash discharge tube when sync contacts are closed, and a terminal connected to the sync contacts and to first and second terminals of the trigger capacitor, unidirectional current control means is inserted between one of the contacts connected to said first terminal of the trigger capacitor and one terminal of the power source so as to interrupt the short circuit current when the contact connected to said second terminal of the trigger capacitor and the terminal of the power source are short circuited.
Inventors
- 👤 Zenzo Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:04
CPC Classifications
H; H02; H02M; H02M3/00; H02M3/22; H02M3/24; H02M3/28; H02M3/325; H02M3/335; H02M3/338; H02M3/3382; H02M3/3384; H02M3/3381; H05; H05B; H05B41/00; H05B41/14; H05B41/30; H05B41/32
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
123 words
A stroboscopic device comprising: a. a power source, b. a flash discharge tube electrically connected in parallel to said power source, c. trigger circuit means for triggering said flash discharge tube, said trigger circuit means including a capacitor which is charged by said power source, d. a pair of sync contacts connected to first and second terminals of said capacitor, said capacitor being actuated or discharged when said pair of sync contacts are closed, and e. unidirection current control means inserted between one of the terminals of said power source and one of said pair of sync contacts for interrupting the short circuit current when the other of said pair of contacts and the other terminal of said power source are short circuited.
Claim 2
Dependent Claim
123 words
A stroboscopic device comprising: a. a power source, b. a flash discharge tube electrically connected in parallel to said power source, c. trigger circuit means for triggering said flash discharge tube, said trigger circuit means including a capacitor which is charged by said power source, d. a pair of sync contacts connected to first and second terminals of said capacitor, said capacitor being actuated or discharged when said pair of sync contacts are closed, and e. unidirection current control means inserted between one of the terminals of said power source and one of said pair of sync contacts for interrupting the short circuit current when the other of said pair of contacts and the other terminal of said power source are short circuited.
Claim 3
Dependent Claim
20 words
A stroboscopic device as set forth in claim 1 wherein said unidirectional current control means comprises at least one diode.
Claim 4
Dependent Claim
20 words
A stroboscopic device as set forth in claim 1 wherein said unidirectional current control means comprises at least one transistor.
Claim 5
Dependent Claim
20 words
A stroboscopic device as set forth in claim 1 wherein said unidirectional current control means comprises at least one thyristor.
References Cited (Backward Citations)
US3569779A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-17 | 1979-05-19 | 1979-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-17 | 1983-05-19 | 1983-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-17 | 1987-05-19 | 1987-11-18 | $7700.00 | Window Closed / Lapsed |