US3769556A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic actuated switch apparatus including shunt
Assignee: Individual
•
Filing: 1972-07-14
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Granted: 1973-10-30
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Expires: 1992-07-14
Abstract
Abstract A magnetic actuated switch apparatus including a shunt circuit for temporarily bypassing the switch in the absence of the magnet is described. Such apparatus is especially adapted for burglar alarm systems which require arming without setting off the alarm while opening the door in the process of departing from the premises. The switch is solid state in nature utilyzing an SCR or TRIAC as the shunting element for a magentic reed, and also incorporates means for preventing turn-on of the SCR or TRIAC when the magnetic reed opens upon subsequent opening of the door to the premises.
Inventors
- 👤 I Feldman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:16
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/02; G08B13/08
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
202 words
A magnetic actuated switch with incorporated shunt circuit for use in alarm systems, comprising normally-open contacts which will close in response to a locally provided magnetic field, a bistable electronic switch having main terminals and a turn-on connection, the main terminals of the electronic switch being connected in parallel with the normally-open contacts, a source of D.C. voltage, means for connecting the D.C. source to the normally-open contacts whereby closing of the contacts enables application of D.C. voltage to an external load circuit, means for temporarily connecting the electronic switch turn-on connection to the D.C. source for turning on the electronic switch to shunt the normally-open contacts allowing application of the D.C. voltage to the external load circuit, said electronic switch turning off when the normally-open contacts close in response to the magnetic field whereby the D.C. voltage continues to be applied to the external load circuit, the next removal of the magnetic field which reopens the normally open contacts interrupting the load circuit and creating a temporary condition tending to turn-on the electronic switch, and means operatively coupled to the electronic switch for preventing turn-on thereof when the normally-open contacts reopen to thereby prevent undesired reclosing of the interrupted load circuit.
Claim 2
Dependent Claim
202 words
A magnetic actuated switch with incorporated shunt circuit for use in alarm systems, comprising normally-open contacts which will close in response to a locally provided magnetic field, a bistable electronic switch having main terminals and a turn-on connection, the main terminals of the electronic switch being connected in parallel with the normally-open contacts, a source of D.C. voltage, means for connecting the D.C. source to the normally-open contacts whereby closing of the contacts enables application of D.C. voltage to an external load circuit, means for temporarily connecting the electronic switch turn-on connection to the D.C. source for turning on the electronic switch to shunt the normally-open contacts allowing application of the D.C. voltage to the external load circuit, said electronic switch turning off when the normally-open contacts close in response to the magnetic field whereby the D.C. voltage continues to be applied to the external load circuit, the next removal of the magnetic field which reopens the normally open contacts interrupting the load circuit and creating a temporary condition tending to turn-on the electronic switch, and means operatively coupled to the electronic switch for preventing turn-on thereof when the normally-open contacts reopen to thereby prevent undesired reclosing of the interrupted load circuit.
Claim 3
Dependent Claim
30 words
A magnetic actuated switch as set forth in claim 1 wherein the turn-on preventing means for the electronic switch comprises a capacitor connected in parallel with the switch main terminals.
Claim 4
Dependent Claim
22 words
A magnetic actuated switch as set forth in claim 2 wherein the capacitor has a capacitance of at least 0.02 Mu fd.
Claim 5
Dependent Claim
50 words
A magnetic actuated switch as set forth in claim 2 wherein the electronic switch comprises an SCR having anode and cathode main terminals and a gate connection, the capacitor is connected across the anode and caThode, and a push button is provided for temporarily connecting the gate to the anode.
Claim 6
Dependent Claim
49 words
A magnetic actuated switch as claimed in claim 2 wherein the electronic switch comprises a TRIAC having two anode main terminals and a gate connection, the capacitor is connected across the two anodes, and a push button is provided for temporarily connecting the gate to one of the anodes.
Claim 7
Dependent Claim
21 words
A magnetic actuated switch as set forth in claim 3 wherein the normally-open contacts are part of a magnetic reed switch.
Claim 8
Dependent Claim
106 words
A magnetic actuated switch as claimed in claim 6 and further comprising a housing having two terminals and a push-button, said reed switch being inside the housing with its normally-open contacts connected to the housing terminals, said capacitor being inside the housing and being connected to the housing terminals, said electronic switch being an SCR or TRIAC having main terminals and a gate turn-on connection and being inside the housing with its main terminals connected to the housing terminals and with its gate connected to one side of the push button, the other side of the push button being connected to one of the housing terminals.
Claim 9
Dependent Claim
104 words
A burglar alarm system comprising a magnetic actuated switch as claimed in claim 1, in combination with a panel comprising a protective relay having a coil and normally closed contacts which are maintained open upon energization of the coil, said protective relay coil being connected in series with the magnetic actuated switch normally open contacts and constituting the said external load circuit, said D.C. source being connected in series with the said coil and the magnetic actuated switch, an outwardly opening door, and a magnet mounted on the door and adapted to close the normally-open contacts when the door is in a closed position.
Claim 10
Dependent Claim
41 words
A burglar alarm system as claimed in claim 8 and further including an alarm device connected in series with the contacts of the protective relay and causing an alarm when the latter close in reponse to interruption of the load circuit.
Claim 11
Dependent Claim
37 words
A burglar alarm system as claimed in claim 9 and further including on the panel a holding relay for the alarm device and adapted to maintain the alarm device circuit closed when actuated to sound the alarm.
Claim 12
Dependent Claim
126 words
A burglar alarm system comprising a magnetic actuated switch as claimed in claim 7, in combination with a separate panel comprising a protective relay having a coil and normallyclosed contacts which are maintained open upon energization of the coil, said protective relay coil being connected in series with the magnetic actuated switch and the D.C. source and constituting the external load circuit, an outwardly opening door, a magnet mounted on the door and adapted to close the normally-open contacts when the door is in a closed position, an alarm device connected in series with the contacts of the protective relay, and a holding relay on the panel for the alarm device and adapted to maintain the alarm device circuit closed when actuated to sound the alarm.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |