US3771019A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flasher circuit
Assignee: Meridan Industries Inc
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Filing: 1972-06-23
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Granted: 1973-11-06
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Expires: 1992-06-23
Abstract
Abstract A flasher circuit is disclosed for intermittently energizing a lamp load such as the turn signal lamps of an automotive vehicle. The circuit operates in the manner of a relaxation oscillator and comprises a resistance capacitance timing circuit, a bistable trigger circuit controlled thereby, and a load switching means which in one embodiment is a power transistor and which in another embodiment is a relay switch. In the standby condition the bistable trigger circuit is held in one stable state with the switching means open and the lamp load is deenergized. When the turn signal switch is closed the timing circuit alternately switches the trigger circuit from one state to the other to flash the lamp load.
Inventors
- 👤 J Bolinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 03:01
CPC Classifications
H; H05; H05B; H05B39/00; H05B39/09; B; B60; B60Q; B60Q1/00; B60Q1/26; B60Q1/34; B60Q1/38; B60Q1/382
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
311 words
A flasher circuit for lamp comprising a voltage source, a timing capacitor and an isolation resistor, a bistable trigger circuit, said timing capacitor being connected across the input of the trigger circuit through said isolation resistor; a first charging circuit including a current limiting resistor and a timing resistor connected in series with the voltage source across the timing capacitor to provide a standby input current for the trigger circuit, said current limiting resistor being small enough so that said input current is sufficient to hold the trigger circuit in a first stable state, a lamp load, manually actuated switching means connected in series with the load, an electrically controlled switching means having an input circuit and an output circuit, the output circuit being connected in series with the load, said voltage source and said manually actuated switching means, a driver amplifier having an input connected with the output of the trigger circuit and an output connected with the input circuit of said electrically controlled switching means, a discharge circuit connecting said timing capacitor across said load through the manually actuated switch when it is closed to thereby initiate flashing of the lamp load by discharging the capacitor to switch the trigger circuit to its second stable state and close the electrically controlled switching means, and a second charging circuit connecting said voltage souRce across said timing capacitor through the electrically controlled switching means when it is closed whereby the lamp load remains energized until the timing capacitor is charged sufficiently to switch the trigger circuit back to its first stable state and thereby opens the electrically controlled switch, said current limiting resistor being large enough so that current therethrough is insufficient to light the lamps, whereby said discharge circuit is effectively reconnected and the flashing of the lamp load is repeated as long as the manually actuated switch is closed.
Claim 2
Dependent Claim
311 words
A flasher circuit for lamp comprising a voltage source, a timing capacitor and an isolation resistor, a bistable trigger circuit, said timing capacitor being connected across the input of the trigger circuit through said isolation resistor; a first charging circuit including a current limiting resistor and a timing resistor connected in series with the voltage source across the timing capacitor to provide a standby input current for the trigger circuit, said current limiting resistor being small enough so that said input current is sufficient to hold the trigger circuit in a first stable state, a lamp load, manually actuated switching means connected in series with the load, an electrically controlled switching means having an input circuit and an output circuit, the output circuit being connected in series with the load, said voltage source and said manually actuated switching means, a driver amplifier having an input connected with the output of the trigger circuit and an output connected with the input circuit of said electrically controlled switching means, a discharge circuit connecting said timing capacitor across said load through the manually actuated switch when it is closed to thereby initiate flashing of the lamp load by discharging the capacitor to switch the trigger circuit to its second stable state and close the electrically controlled switching means, and a second charging circuit connecting said voltage souRce across said timing capacitor through the electrically controlled switching means when it is closed whereby the lamp load remains energized until the timing capacitor is charged sufficiently to switch the trigger circuit back to its first stable state and thereby opens the electrically controlled switch, said current limiting resistor being large enough so that current therethrough is insufficient to light the lamps, whereby said discharge circuit is effectively reconnected and the flashing of the lamp load is repeated as long as the manually actuated switch is closed.
Claim 3
Dependent Claim
19 words
The invention as defined in claim 1 including a filter capacitor connected across the input of the trigger circuit.
Claim 4
Dependent Claim
16 words
The invention as defined in claim 1 wherein said electrically controlled switch means is a relay.
Claim 5
Dependent Claim
16 words
The invention as defined in claim 1 wherein said electrically controlled switch means is a transistor.
Claim 6
Dependent Claim
89 words
The invention as defined in claim 1 wherein said trigger comprises two transistors, the emitters of said two transistors being connected together and being connected through a common resistor to one terminal of the voltage source, the collectors of said two transistors being connected to the other terminal of the voltage source, the base of the first of said two transistors being connected with said isolation resistor and the base of the second of said two transistors being connected with the collector of the first of said two transistors.
Claim 7
Dependent Claim
29 words
The invention as defined in claim 5 including a capacitor connected between the bases of the two transistors of the trigger circuit to eliminate the effect of noise pulses.
References Cited (Backward Citations)
US3329868A
Cited
US3452248A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-05 | 1977-05-07 | 1977-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-05 | 1981-05-07 | 1981-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-05 | 1985-05-07 | 1985-11-06 | $7700.00 | Window Closed / Lapsed |