US3873980A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sound communication system
Assignee: TDK Micronas GmbH
•
Filing: 1973-10-29
•
Granted: 1975-03-25
•
Expires: 1993-10-29
Abstract
Abstract A communication system for an emergency vehicle including a provision for selectively producing plural automatically and manually controlled siren sounds, the sound broadcast of radio reception and the sound amplification of the input to a microphone. A complete momentary-contact, pushbutton console may be employed, if desired, by short circuiting all the inputs to ground except that corresponding to the mode of operation selected. Start up instability is also eliminated. A selector pushbutton performs the dual function of manual siren control. Negative feedback from the speaker is provided selectively for radio and public address sytem use. Common use of components reduces cost and complexity. For example, common use of a voltage controlled oscillator, two amplifier stages, a driver and a speaker assembly is made. Radio input is turned on by an alternate action switch. As described in the specification, the action of ''''turning on'''' the radio shorts out all siren functions by firing silicon controlled rectifiers. The microphone input is turned on by pushing the ''''push to talk'''' switch thereon. This action fires all the siren shorting silicon controlled rectifiers through a pulse amplifier.
Inventors
- 👤 Gordon S Carroll
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:29
CPC Classifications
G; G08; G08B; G08B3/00; G08B3/10
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
356 words
A multipurpose sound communication system comprising: first and second D.C. voltage sources having first and second output leads, respectively, connected to first and second output junctions, respectively, said first and second sources being adapted to produce respective first and second output signals on said first and second leads thereof, respectively, said first and second signals having first and second respective first and second magnitudes which are functions of time different from each other; a voltage controlled oscillator (VCO) having an input lead and an output lead, said VCO being adapted to produce an output signal on said output lead thereof having at least an A.C. of an audio frequency controlled in accordance with the magnitude of the input signal applied to the said input lead thereof; first and second connection means connected from said first and second output junctions, respectively, to said VCO input lead, said first connection means being actuatable to produce effectively an open circuit between said first source output junction and said VCO input lead when said first source output junction is short circuited to ground, said first connection means being actuable to produce effectively a conductive path between said first source output junction and said VCO input lead when said first source output junction is not short circuited to ground, said second connection means being actuable to produce effectively an open circuit between said second source output junction and said VCO input lead when said second source output junction is short circuited to ground, said second connection means being actuable to produce effectively a conductive path between said second source output junction anD said VCO input lead when said second source output junction is not short circuited to ground; manually actuable means connected from said first and second output junctions, respectively, to ground, said manually actuatable means being selectively operable to short circuit one but not the other of said first and second output junctions to ground; and output means having an input lead connected from said VCO output lead for broadcasting audible sound in accordance with the amplitude and frequency of said VCO output signal component on said VCO output lead.
Claim 2
Dependent Claim
356 words
A multipurpose sound communication system comprising: first and second D.C. voltage sources having first and second output leads, respectively, connected to first and second output junctions, respectively, said first and second sources being adapted to produce respective first and second output signals on said first and second leads thereof, respectively, said first and second signals having first and second respective first and second magnitudes which are functions of time different from each other; a voltage controlled oscillator (VCO) having an input lead and an output lead, said VCO being adapted to produce an output signal on said output lead thereof having at least an A.C. of an audio frequency controlled in accordance with the magnitude of the input signal applied to the said input lead thereof; first and second connection means connected from said first and second output junctions, respectively, to said VCO input lead, said first connection means being actuatable to produce effectively an open circuit between said first source output junction and said VCO input lead when said first source output junction is short circuited to ground, said first connection means being actuable to produce effectively a conductive path between said first source output junction and said VCO input lead when said first source output junction is not short circuited to ground, said second connection means being actuable to produce effectively an open circuit between said second source output junction and said VCO input lead when said second source output junction is short circuited to ground, said second connection means being actuable to produce effectively a conductive path between said second source output junction anD said VCO input lead when said second source output junction is not short circuited to ground; manually actuable means connected from said first and second output junctions, respectively, to ground, said manually actuatable means being selectively operable to short circuit one but not the other of said first and second output junctions to ground; and output means having an input lead connected from said VCO output lead for broadcasting audible sound in accordance with the amplitude and frequency of said VCO output signal component on said VCO output lead.
Claim 3
Dependent Claim
65 words
The invention as defined in claim 1, wherein said manually actuable means has a first common input lead adapted to receive pulses to establish all of said short circuits selectively, a second common input lead for connection from a source of an approximately constant D.C. voltage, and a main power switch and a capacitor connected in series between said first and second common input leads.
Claim 4
Dependent Claim
31 words
The invention as defined in claim 1, wherein one of said first and second connection means includes a diode poled to be conductive in a direction toward said VCO input lead.
Claim 5
Dependent Claim
33 words
The invention as defined in claim 3, wherein the other of said first and second connection means also includes a diode poled to be conductive in a direction toward said VCO input lead.
Claim 6
Dependent Claim
23 words
The invention as defined in claim 3, wherein the other of said first and second connection means includes a series connected transistor switch.
Claim 7
Dependent Claim
380 words
The invention as defined in claim 1, wherein said manually actuable means includes first and second circuits, and first and second manually actuably momentary contact double-pole, double-throw switch means; said first and second circuits having third and fourth junctions, respectively, fifth and sixth junctions, respectively, seventh and eighth junctions, respectively, first and second diodes, respectively, first and second resistors, respectively, third and fourth resistors, respectively, fifth and sixth resistors, respectively, and first and second silicon-controlled rectifiers, respectively; said first diode being connected from said first output junction to said third junction and being poled to be conductive toward the latter; said second diode being connected from said second output junction to said fourth junction and being poled to be conductive toward the latter; said first and second resistors being respectively connected from said third and fourth junctions to an approximately constant potential conductor; said first and second silicon-controlled rectifiers having first and second anodes, respectively, first and second cathodes, respectively, and first and second gates, respectively; said first and second anodes being connected from said third and fourth junctions, respectively; said first and second cathodes being connected to said fifth and sixth junctions, respectively; said first and second gates being connected from said seventh and eighth junctions, respectively; said third and fourth resistors being respectively connected from said seventh and eighth junctions to said fifth and sixth junctions, respectively; a common lead; said fifth and sixth resistors being connected respectively from said seventh and eighth junctions to said common lead; said first and second switch means including first and second normally closed switches, respectively, and first and second normally open switches, respectively; said first switch means normally open switch being connected between an approximately constant potential conductor and said common lead; said second switch means normally open switch being connected in parallel with said first switch means normally open switch; said first switch means switches being ganged in a manner such that said normally closed switch thereof makes after said normally open switch thereof breaks; said second switch means switches being ganged in a manner such that said normally closed switch thereof makes after said normally open switch thereof breaks; said first and second swiTch means normally closed switches being respectively connected from said fifth and sixth junctions to ground.
Claim 8
Dependent Claim
31 words
The invention as defined in claim 6, wherein one of said first and second connection means includes a diode poled to be conductive in a direction toward said VCO input lead.
Claim 9
Dependent Claim
33 words
The invention as defined in claim 7, wherein the other of said first and second connection means also includes a diode poled to be conductive in a direction toward said VCO input lead.
Claim 10
Dependent Claim
23 words
The invention as defined in claim 7, wherein the other of said first and second connection means includes a series connected transistor switch.
References Cited (Backward Citations)
US3747092A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |