US3664247A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Surveillance camera with circuit for automatic activation
Assignee: Continental Instruments Corp
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Filing: 1970-07-06
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Granted: 1972-05-23
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Expires: 1990-07-06
Abstract
Abstract A camera which is automatically activated in response to the change in resistance of a photocell due to the occurrence of an event intended to be detected and recorded. The camera is provided with a network for translating such change in electrical resistance into the automatic activation of the camera drive motor. The camera drive motor is controlled by a relay which activates the motor only when the relay is energized. The relay is in series with a pair of transistor amplifiers, both on which must be conducting for the relay to remain in energized condition. The change in resistance of the photocell creates a change of potential across a condenser which, in turn, causes a temporary flow of current, which current affects the triggering current of a third transistor amplifier. This third transistor amplifier controls the other two transistor amplifiers in such a manner that whenever the triggering current of the third transistor amplifier is changed, either upwardly or downwardly, from a fixed value, one or the other of the two transistor amplifiers in series with the control relay will be rendered nonconducting to unenergize the control relay and thus activate the drive motor of the camera.
Inventors
- 👤 Edward M Tellerman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:12
CPC Classifications
G; G03; G03B; G03B17/00; G03B17/38
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
258 words
A camera adapted to be automatically activated in response to the occurrence of events intended to be recorded comprising, in combination, 1. drive means for activating said camera, 2. a device whose electrical resistance varies in response to the occurrence of said events, and 3. a network for translating the change in electrical resistance of said device into the energization of said drive means whereby the occurrence of said events automatically activates said camera, said electrical network comprising, a. a condenser electrically related to said device so that a change in resistance of said device causes a change in the charge of the condenser and an accompanying condenser current flow, b. electrical control means which, when unenergized, causes the energization of said drive motor, c. a pair of transistor amplifiers in series with said control means and with a supply of D.C. voltage whereby said transistor amplifiers must both be conducting to maintain said control means in energized condition, d. a third transistor amplifier electrically related to said pair of transistor amplifiers so that the two transistor amplifiers of said pair are both conducting only when said third transistor amplifier receives triggering current within a predetermined value range, e. said condenser being electrically related to said third transistor amplifier so that any condenser current flow resulting from a change of resistance of said device causes a change in the triggering current of said third transistor amplifier, whereby one transistor amplifier of said pair becomes non-conducting to de-energize said control means and effectuate the energization of said drive motor.
Claim 2
Dependent Claim
258 words
A camera adapted to be automatically activated in response to the occurrence of events intended to be recorded comprising, in combination, 1. drive means for activating said camera, 2. a device whose electrical resistance varies in response to the occurrence of said events, and 3. a network for translating the change in electrical resistance of said device into the energization of said drive means whereby the occurrence of said events automatically activates said camera, said electrical network comprising, a. a condenser electrically related to said device so that a change in resistance of said device causes a change in the charge of the condenser and an accompanying condenser current flow, b. electrical control means which, when unenergized, causes the energization of said drive motor, c. a pair of transistor amplifiers in series with said control means and with a supply of D.C. voltage whereby said transistor amplifiers must both be conducting to maintain said control means in energized condition, d. a third transistor amplifier electrically related to said pair of transistor amplifiers so that the two transistor amplifiers of said pair are both conducting only when said third transistor amplifier receives triggering current within a predetermined value range, e. said condenser being electrically related to said third transistor amplifier so that any condenser current flow resulting from a change of resistance of said device causes a change in the triggering current of said third transistor amplifier, whereby one transistor amplifier of said pair becomes non-conducting to de-energize said control means and effectuate the energization of said drive motor.
Claim 3
Dependent Claim
106 words
A camera in accordance with claim 1, wherein there is further provided amplifier means for amplifying said accompanying condenser current flow, resistor means electrically related to said amplified current so that the latter correspondingly affects the potential across said resistor means, another condenser electrically related to said resistor means so that a change of potential thereacross causes a change in the charge of said another condenser and an accompanying another condenser current flow which is greater than said first mentioned accompanying condenser current flow, said another condenser being related to said third transistor amplifier so that any another condenser current flow affects the triggering circuit thereof.
Claim 4
Independent Claim
15 words
a device whose electrical resistance varies in response to the occurrence of said events, and
Claim 5
Independent Claim
15 words
a device whose electrical resistance varies in response to the occurrence of said events, and
Claim 6
Dependent Claim
22 words
A camera in accordance with claim 2, wherein said resistor means includes a variable resistor for adjusting the sensitivity of said network.
Claim 7
Dependent Claim
213 words
a network for translating the change in electrical resistance of said device into the energization of said drive means whereby the occurrence of said events automatically activates said camera, said electrical network comprising, a. a condenser electrically related to said device so that a change in resistance of said device causes a change in the charge of the condenser and an accompanying condenser current flow, b. electrical control means which, when unenergized, causes the energization of said drive motor, c. a pair of transistor amplifiers in series with said control means and with a supply of D.C. voltage whereby said transistor amplifiers must both be conducting to maintain said control means in energized condition, d. a third transistor amplifier electrically related to said pair of transistor amplifiers so that the two transistor amplifiers of said pair are both conducting only when said third transistor amplifier receives triggering current within a predetermined value range, e. said condenser being electrically related to said third transistor amplifier so that any condenser current flow resulting from a change of resistance of said device causes a change in the triggering current of said third transistor amplifier, whereby one transistor amplifier of said pair becomes non-conducting to de-energize said control means and effectuate the energization of said drive motor.
Claim 8
Dependent Claim
213 words
a network for translating the change in electrical resistance of said device into the energization of said drive means whereby the occurrence of said events automatically activates said camera, said electrical network comprising, a. a condenser electrically related to said device so that a change in resistance of said device causes a change in the charge of the condenser and an accompanying condenser current flow, b. electrical control means which, when unenergized, causes the energization of said drive motor, c. a pair of transistor amplifiers in series with said control means and with a supply of D.C. voltage whereby said transistor amplifiers must both be conducting to maintain said control means in energized condition, d. a third transistor amplifier electrically related to said pair of transistor amplifiers so that the two transistor amplifiers of said pair are both conducting only when said third transistor amplifier receives triggering current within a predetermined value range, e. said condenser being electrically related to said third transistor amplifier so that any condenser current flow resulting from a change of resistance of said device causes a change in the triggering current of said third transistor amplifier, whereby one transistor amplifier of said pair becomes non-conducting to de-energize said control means and effectuate the energization of said drive motor.
Claim 9
Dependent Claim
26 words
A camera in accordance with claim 1, wherein the electrical control means comprises a relay which, when unenergized, is operative to energize the camera drive motor.
Claim 10
Dependent Claim
59 words
A camera in accordance with claim 1, wherein said third transistor amplifier is in shunting relation with the triggering circuit of one of the two transistor amplifiers of said pair so that an increase in current flow through said third transistor amplifier causes a corresponding decrease of triggering current of said one transistor amplifier to render the latter non-conducting.
Claim 11
Dependent Claim
45 words
A camera in accordance with claim 5, wherein the triggering circuit of the other of the two transistor amplifiers is in series with the emitter of said third transistor amplifier whereby said other transistor amplifier is rendered non-conducting when said third transistor amplifier is non-conducting.
Claim 12
Dependent Claim
27 words
A camera in accordance with claim 6, wherein the device is a photocell whose electrical resistance varies in response to a change of light within range thereof.
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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) | 1975-05-23 | 1975-11-22 | 1976-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-23 | 1979-11-22 | 1980-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-23 | 1983-11-22 | 1984-05-23 | $7700.00 | Window Closed / Lapsed |