US4139842A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Audible alarm unit
Assignee: Individual
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Filing: 1977-04-14
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Granted: 1979-02-13
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Expires: 1997-04-14
Abstract
Abstract The present invention is an audible alarm unit including a coil, a resistor, an NPN transistor, and a piezoelectric transducer having first and second electrodes and a feedback electrode. The collector and emitter of the transistor and the coil are connected in series between positive and negative terminals of a direct current power source. The base of the transistor is connected to the collector through the resistor. The first and second electrodes of the piezoelectric transducer are connected either to both ends of the coil or to the collector and emitter of the transistor, respectively. The feedback electrode of the piezoelectric transducer is connected to the base of the transistor.
Inventors
- 👤 Nobuhiko Fujita
- 👤 Hiroshi Saito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:27
CPC Classifications
G; G08; G08B; G08B3/00; G08B3/10; B; B06; B06B; B06B1/00; B06B1/02; B06B1/0207; B06B1/0223; B06B1/0238; B06B1/0246; B06B1/0261; H; H03; H03B; H03B5/00; H03B5/30; H03B5/32; H03B5/323; B06B2201/00; B06B2201/50; B06B2201/55
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
121 words
An audible alarm unit comprising: a direct current power source having a positive terminal and a negative terminal; a coil; a resistor; a transistor having a collector, an emitter and a base, said collector, said emitter and said coil being connected in series between said positive and negative terminals of said direct current power source, said base being connected to said collector through said resistor; a piezoelectric transducer having first and second electrodes opposite to each other and a feedback electrode separate from said second electrode, said first electrode and said second electrode being connected to respective ends of said coil, said feedback electrode being connected to said base of said transistor; and a capacitor connected in parallel to said coil.
Claim 2
Dependent Claim
121 words
An audible alarm unit comprising: a direct current power source having a positive terminal and a negative terminal; a coil; a resistor; a transistor having a collector, an emitter and a base, said collector, said emitter and said coil being connected in series between said positive and negative terminals of said direct current power source, said base being connected to said collector through said resistor; a piezoelectric transducer having first and second electrodes opposite to each other and a feedback electrode separate from said second electrode, said first electrode and said second electrode being connected to respective ends of said coil, said feedback electrode being connected to said base of said transistor; and a capacitor connected in parallel to said coil.
Claim 3
Dependent Claim
25 words
An audible alarm unit as claimed in claim 1, further comprising a further resistor connected between said feedback electrode and said base of said transistor.
Claim 4
Dependent Claim
129 words
An audible alarm unit comprising: a direct current power source having a positive terminal and a negative terminal; a coil; a resistor; a transistor having a collector, an emitter and a base, said collector, said emitter and said coil being connected in series between said positive and negative terminals of said direct current power source, said base being connected to said collector through said resistor; a piezoelectric transducer having first and second electrodes opposite to each other and a feedback electrode separate from said second electrode, said first electrode being connected to said collector of said transistor, said second electrode being connected to said emitter of said transistor and said feedback electrode being connected to said base of said transistor; and a capacitor connected in parallel to said coil.
Claim 5
Dependent Claim
129 words
An audible alarm unit comprising: a direct current power source having a positive terminal and a negative terminal; a coil; a resistor; a transistor having a collector, an emitter and a base, said collector, said emitter and said coil being connected in series between said positive and negative terminals of said direct current power source, said base being connected to said collector through said resistor; a piezoelectric transducer having first and second electrodes opposite to each other and a feedback electrode separate from said second electrode, said first electrode being connected to said collector of said transistor, said second electrode being connected to said emitter of said transistor and said feedback electrode being connected to said base of said transistor; and a capacitor connected in parallel to said coil.
Claim 6
Dependent Claim
25 words
An audible alarm unit as claimed in claim 3, further comprising a further resistor connected between said feedback electrode and said base of said transistor.
Claim 7
Dependent Claim
126 words
An audible alarm unit comprising: a direct current power source having a positive terminal and a negative terminal; a coil; a resistor; a transistor having a collector, an emitter and a base, said collector, said emitter and said coil being connected in series between said positive and negative terminals of said direct current power source, said base being connected to said collector through said resistor; a piezoelectric transducer having first and second electrodes opposite to each other and a feedback electrode separate from said second electrode, said first and second electrodes being connected to respective ends of said coil, said feedback electrode being connected to said base of said transistor; and a capacitor having terminals connected to said collector and said emitter of said transistor respectively.
Claim 8
Dependent Claim
126 words
An audible alarm unit comprising: a direct current power source having a positive terminal and a negative terminal; a coil; a resistor; a transistor having a collector, an emitter and a base, said collector, said emitter and said coil being connected in series between said positive and negative terminals of said direct current power source, said base being connected to said collector through said resistor; a piezoelectric transducer having first and second electrodes opposite to each other and a feedback electrode separate from said second electrode, said first and second electrodes being connected to respective ends of said coil, said feedback electrode being connected to said base of said transistor; and a capacitor having terminals connected to said collector and said emitter of said transistor respectively.
Claim 9
Dependent Claim
25 words
An audible alarm unit as claimed in claim 5, further comprising a further resistor connected between said feedback electrode and said base of said transistor.
Claim 10
Dependent Claim
136 words
An audible alarm unit comprising: a direct current power source having a positive terminal and a negative terminal; a coil; a resistor; a transistor having a collector, an emitter and a base, said collector, said emitter and said coil being connected in series between said positive and negative terminals of said direct current power source, said base being connected to said collector through said resistor; a piezoelectric transducer having first and second electrodes opposite to each other and a feedback electrode separate from said second electrode, said first electrode being connected to said collector of said transistor, said second electrode being connected to said emitter of said transistor and said feedback electrodes being connected to said base of said transistor; and a capacitor having terminals connected to said collector and said emitter of said transistor respectively.
Claim 11
Dependent Claim
136 words
An audible alarm unit comprising: a direct current power source having a positive terminal and a negative terminal; a coil; a resistor; a transistor having a collector, an emitter and a base, said collector, said emitter and said coil being connected in series between said positive and negative terminals of said direct current power source, said base being connected to said collector through said resistor; a piezoelectric transducer having first and second electrodes opposite to each other and a feedback electrode separate from said second electrode, said first electrode being connected to said collector of said transistor, said second electrode being connected to said emitter of said transistor and said feedback electrodes being connected to said base of said transistor; and a capacitor having terminals connected to said collector and said emitter of said transistor respectively.
Claim 12
Dependent Claim
25 words
An audible alarm unit as claimed in claim 7, further comprising a further resistor connected between said feedback electrode and said base of said transistor.
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) | 1982-02-12 | 1982-08-14 | 1983-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-12 | 1986-08-14 | 1987-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-12 | 1990-08-14 | 1991-02-13 | $7700.00 | Window Closed / Lapsed |