GB2250618A - An electrical switching device - Google Patents

An electrical switching device Download PDF

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Publication number
GB2250618A
GB2250618A GB9026720A GB9026720A GB2250618A GB 2250618 A GB2250618 A GB 2250618A GB 9026720 A GB9026720 A GB 9026720A GB 9026720 A GB9026720 A GB 9026720A GB 2250618 A GB2250618 A GB 2250618A
Authority
GB
United Kingdom
Prior art keywords
switch
switching device
electrical switching
condition
sound
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB9026720A
Other versions
GB9026720D0 (en
Inventor
Peter Franks
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
TREVI SpA Ltd
Original Assignee
TREVI SpA Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by TREVI SpA Ltd filed Critical TREVI SpA Ltd
Priority to GB9026720A priority Critical patent/GB2250618A/en
Publication of GB9026720D0 publication Critical patent/GB9026720D0/en
Publication of GB2250618A publication Critical patent/GB2250618A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
    • H03K3/02—Generators characterised by the type of circuit or by the means used for producing pulses
    • H03K3/027—Generators characterised by the type of circuit or by the means used for producing pulses by the use of logic circuits, with internal or external positive feedback
    • H03K3/033—Monostable circuits
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/94—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B47/00—Circuit arrangements for operating light sources in general, i.e. where the type of light source is not relevant
    • H05B47/10—Controlling the light source
    • H05B47/105—Controlling the light source in response to determined parameters
    • H05B47/115—Controlling the light source in response to determined parameters by determining the presence or movement of objects or living beings
    • H05B47/12—Controlling the light source in response to determined parameters by determining the presence or movement of objects or living beings by detecting audible sound
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
    • Y02B20/40—Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

An electrical switching device comprises a sound sensitive electronic switch, which includes a semiconductor switching element 12, a first manually operable on/off switch 10 connected electrically in series with the sound sensitive electronic switch between first and second terminals 14 and 15, and a second manually operable on/off switch 11 between the first and second terminals and electrically in parallel with the electronic switch, whereby a circuit will be made between the first and second terminals when the second switch 11 is in an "on" condition and, in response to sound, when the first switch 10 is in an "on" condition and the second switch 11 is in an "off" condition. <IMAGE>

Description

"Electrical Switching Device" This invention relates to an electrical switching device, and more particularly to such a device which can be made to operate in response to sound.
According to the present invention, there is provided an electrical switching device comprising a sound sensitive electronic switch, a first manually operable on/off switch connected- electrically in series with the sound sensitive electronic switch between first and second terminals, and a second manually operable on/off switch connected between the first and second terminals and electrically in parallel with the electronic switch and the first manually operable switch, whereby a circuit will be made between the first and second terminals when the second switch is in an "on" condition and, in response to sound, when the first switch is in an "on" condition and the second switch is in an "off" condition.
Preferably, the sound sensitive switch comprises an audio-electrical transducer for producing an electrical signal in response to sound, a timing circuit operable in response to a transducer output signal above a certain level, and a semiconductor switching element operable in response to the timing circuit.
Preferably, the electrical switching device also comprises means for adjusting the sensitivity of the sound sensitive electronic switch.
Preferably, the timing circuit comprises a monostable multivibrator which is in use triggered into its unstable state when the transducer output signal is above said certain level and which, when triggered into its unstable state, causes the semiconductor switching element to adopt an "on" condition, and a timing network (e.g. an RC network) connected to the output of the multivibrator to hold the semiconductor switching element in its "on" condition for a predetermined period of time after the monostable multivibrator has returned to its stable state. This has the advantage that if the output signal of the transducer is still above said certain level when the multivibrator returns to its stable state, the multivibrator will switch again to its unstable state to recharge the timing network without the semiconductor switching element turning off.
In a preferred embodiment, the switching device is designed to operate a lighting circuit and in this case it may be provided with means whereby it can selectively operate filament or fluorescent lamps. In this latter case, the sound sensitive electronic switch may be arranged to derive its power supply from the lamp circuit when said means provide for operation of a filament lamp and may be arranged to derive its power supply from between the live side of a mains supply and true earth when said means provide for operation of a fluorescent lamp.
Preferably, the first and second manually operable switches are toggle switches.
Preferably, the switching device is configured so that it can be used as a substitute for an existing wall mounted plate switch.
The invention will now be more particularly described by way of example only with reference to the accompanying drawings, in which: Figure 1 is an electrical circuit diagram of one embodiment of an electrical switching device according to the present invention, and Figure 2 is a rear view of the switching device configured so that it can be used as a substitute for an existing wall mounted plate switch.
Referring to the drawings, the electrical switching device shown therein is configured so that it can be used as a substitute for an existing wall mounted plate switch for a lighting circuit. The switching device comprises two manually operable toggle switches 10 and 11, and a sound sensitive electronic switch including a semiconductor switching element in the form of a triac 12, all mounted on a switch plate 13.
The switching device has two mains terminals 14 and 15, and an earth terminal 16, which in use is connected to true earth. The switch 10 is connected electrically in series with the triac 12 between the terminals 14 and 15, and the switch 11 is also connected between the terminals 14 and 15 and electrically in parallel with the switch 10 and the triac 12.
When the switch 10 is in an 'on" condition and switch 11 is in an "off" condition, the circuit between the terminals 14 and 15 is made when triac 12 switches on in response to sound. When switch 11 is in an "on" condition, the circuit between the terminals 14 and 15 is made regardless of the condition of the switch 10 and triac 12. When both switches 10 and 11 are in "off" conditions, the circuit between the terminals 14 and 15 is interrupted.
The triac 12 is operated by a sound sensitive circuit comprising an electret microphone 17, a timing circuit including a monostable multivibrator (see below) and an RC network 18, and a switching transistor TR1.
The microphone 17 is connected in series with a resistor R1 between supply rails S1 and 52 and has a capacitance of C1.
The sound sensitive circuit includes an A4001 QUAD 2 INPUT NOR GATE integrated circuit IC1 having four gates G1, G2, G3 and G4. Gate G1 is configured as a microphone amplifier, gates G2 and G3 are configured as the monostable multivibrator, and gate G4 is used as a buffer between the monostable multivibrator and the switching transistor TR1.
The microphone 17 is connected via a capacitor C2 to the gate G1 and the output of the gate G1 is connected via a capacitor C6, a rectifier circuit comprising diodes D1 and D2 and capacitor C9, a variable resistor VR1 and a resistor R4 to supply rail S2. The variable resistor VR1 can be adjusted to alter the sensitivity of the sound sensitive electronic switch.
The movable contact of the resistor VR1 is connected to the supply rail S1 via a capacitor C12 and a resistor R3. An NPN transistor TR2 has its base connected to the junction between the capacitor C12 and the resistor R3, its emitter connected to supply rail S2, and its collector connected on one hand to supply rail S1 via a resistor R10 and on the other hand to the input of gate G2.
The transistor TR2 is normally held in a fully conducting state by the voltage applied to its base through resistor R3, but when the microphone 17 detects a sound, a negative going pulse will be applied to the base of transistor TR2 and provided the amplitude of this pulse exceeds a certain value, the transistor TR2 will turn off for the period of the pulse. The collector of transistor TR2 will go high and this will switch the monostable multivibrator into its unstable state.
The output of the monostable multivibrator is connected via a diode D9 on the one hand to the resistor and capacitor of the RC network 18 and on the other hand to the gate G4.
PNP switching transistor TR1 has its base connected to the output of gate G4 via a resistor R7, its emitter connected to supply rail S2 and its collector also connected to supply rail S2 via a diode bridge circuit consisting of two pairs of series connected diodes D4, D6 and D5, D7.
The triac 12 has a charging circuit comprising a resistor R9 and a capacitor Cll connected in series between terminal J1 (see below) and terminal 15. The junction between diodes D4 and D6 is connected to the junction between resistor R9 and capacitor Cll and also to the gate of triac 12 via a diac 19. The junction between diode D5 and diode D7 is connected to terminal 15.
Switching transistor TRl is normally held in a conducting state with its collector virtually at ground potential and in this state it will prevent capacitor Cll from charging as the voltage at the junction between capacitor C11 and resistor R9 will be grounded via diode D4 and transistor TRl. However, when the monostable multivibrator is switched to its unstable state in response to sound above a certain level detected by the microphone 17, a positive going pulse is applied to the base of transistor TR1 and this transistor switches off.
Capacitor Cll then charges via resistor R9 and fires diac 19 which in turn switches triac 12 to a conductive state.
The RC network 18 charges as soon as the monostable multivibrator is switched to its unstable state and the network 18 holds the transistor TR1 off for a predetermined period of time after the multivibrator returns to its stable state. Thus, the triac 12 will remain in a conductive state whilst the multivibrator is in its unstable state and for said predetermined time period thereafter. This has the advantage that if the sound detected by the microphone 17 is still above a certain level when the multivibrator returns to its stable state, the multivibrator will switch again to its unstable state to fully recharge the RC network without the transistor TRl switching back on and hence without the triac switching off.Therefore, when the electrical switching device is in a sound sensitive mode with switch 10 in an "on" condition and switch 11 in an "off" condition, the triac 12 will remain conductive as long as the sound detected by the microphone 17 remains above a certain level and there will be no flickering of lamp 25 as would be the case if the RC network were to be omitted.
Terminals J1, and J2 and J3 are provided so that the switching device can be used to selectively operate a filament or fluorescent lamp. Terminal J1 is connected to the supply rail S1 via a rectifying circuit 20, a voltage limiting circuit 21, and a smoothing circuit 22. Terminal J2 is connected to the junction between the switch 10 and the triac 12. Terminal J3 is connected to the earth terminal 16.When the switching device is to be used to operate a filament lamp, terminals J1 and J2 are connected and the dc power supply to supply rails S1 and S2 is derived from the lamp circuit via the rectifying circuit 20 comprising diode D3 and capacitor C10, the voltage limiting circuit 21 comprising resistor R8 and zener diode Z1, and the smoothing circuit 22 comprising capacitors C5, C7 and C8 and resistors R5 and R6. However, when the switching device is to be used to operate a fluorescent lamp, the voltage developed across the load varies with different types of lighting and is considerably less than with filament lamps.In this case, terminals J1 and J3 are connected so that the voltage supply to the supply rails S1 and S2 is derived from between the live side of the mains supply, which is connected to terminal 15, and true earth, which is connected to terminal J3, again via the rectifying circuit 20, voltage limiting circuit 21, and smoothing circuit 22.
The component parts of the sound sensitive electronic switch are mounted on a printed circuit board 23 fixed to the rear of the switch plate 13. The terminals J1, J2 and J3 are exposed and arranged so that a connector can be connected at will either between terminals Jl and J2 or between terminals J1 and J3.
Variable resistor VR1 can also be adjusted from the rear of the switch plate 13 to adjust the sensitivity of the sound sensitive electronic switch.
The embodiment described above is given by way of example only and various modifications will be apparent to persons skilled in the art without departing from the scope of the invention.

Claims (9)

1. An electrical switching device comprising a sound sensitive electronic switch, a first manually operable on/off switch connected electrically in series with the sound sensitive electronic switch between first and second terminals, and a second manually operable on/off switch connected between the first and second terminals and electrically in parallel with the electronic switch and the first manually operable switch, whereby a circuit will be made between the first and second terminals when the second switch is in an "on" condition and, in response to sound, when the first switch is in an "on" condition and the second switch is in an "off" condition.
2. An electrical switching device as claimed in claim 1, wherein the electrical switching device also comprises means for adjusting the sensitivity of the sound sensitive electronic switch.
3. An electrical switching device as claimed in claim 1 or claim 2, wherein the sound sensitive switch comprises an audio-electrical transducer for producing an electrical signal in response to sound, a timing circuit operable in response to a transducer output signal above a certain level, and a semiconductor switching element operable in response to the timing circuit.
4. An electrical switching device as claimed in claim 3, wherein the timing circuit comprises a monostable multivibrator which is in use triggered into its unstable state when the transducer output signal is above said certain level and which, when triggered into its unstable state, causes the semiconductor switching element to adopt an "on" condition, and a timing network connected to the output of the multivibrator to hold the semiconductor switching element in its "on" condition for a predetermined period of time after the monostable multivibrator has returned to its stable state.
5. An electrical switching device as claimed in any one of the preceding claims, further comprising means whereby it can selectively operate filament or fluorescent lamps.
6. An electrical switching device as claimed in claim 5, wherein the sound sensitive electronic switch is arranged to derive its power supply from the lamp circuit when said means provide for operation of a filament lamp and is arranged to derive its power supply from between the live side of a mains supply and true earth when said means provide for operation of a fluorescent lamp.
7. An electrical switching device as claimed in any one of the preceding claims, wherein the first and second manually operable switches are toggle switches.
8. An electrical switching device as claimed in any one of the preceding claims, configured so that it can be used as a substitute for an existing wall mounted plate switch.
9. An electrical switching device substantially as hereinbefore described with reference to the accompanying drawings.
GB9026720A 1990-12-08 1990-12-08 An electrical switching device Withdrawn GB2250618A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9026720A GB2250618A (en) 1990-12-08 1990-12-08 An electrical switching device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9026720A GB2250618A (en) 1990-12-08 1990-12-08 An electrical switching device

Publications (2)

Publication Number Publication Date
GB9026720D0 GB9026720D0 (en) 1991-01-30
GB2250618A true GB2250618A (en) 1992-06-10

Family

ID=10686700

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9026720A Withdrawn GB2250618A (en) 1990-12-08 1990-12-08 An electrical switching device

Country Status (1)

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GB (1) GB2250618A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2355825A (en) * 1999-07-23 2001-05-02 Allan Marshall A lighting device operated by sound
GB2374185A (en) * 2001-04-05 2002-10-09 Jung Tsung Wei Vibration sensing assembly and controller
WO2011070336A1 (en) * 2009-12-11 2011-06-16 Benmore Ventures Limited Sound-actuated illumination circuit

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1279335A (en) * 1969-07-07 1972-06-28 Novar Electronics Corp Sound responsive device
US3713126A (en) * 1971-02-18 1973-01-23 Novar Electronics Corp Burglar deterrent timing switch
US4103294A (en) * 1971-05-20 1978-07-25 Novar Electronics Corporation Intruder deterrent apparatus and method
GB2068613A (en) * 1980-01-30 1981-08-12 Ozen Corp Acoustically operable electrical switching circuits
GB2077011A (en) * 1980-05-27 1981-12-09 Yeldham Albert James A bedroom light control device
GB2161302A (en) * 1984-07-04 1986-01-08 Christopher Paul Northcott Sound activated light switch
GB2226170A (en) * 1988-11-15 1990-06-20 Waverlink Electronics Limited Sound sensitive electrical switch

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1279335A (en) * 1969-07-07 1972-06-28 Novar Electronics Corp Sound responsive device
US3713126A (en) * 1971-02-18 1973-01-23 Novar Electronics Corp Burglar deterrent timing switch
US4103294A (en) * 1971-05-20 1978-07-25 Novar Electronics Corporation Intruder deterrent apparatus and method
GB2068613A (en) * 1980-01-30 1981-08-12 Ozen Corp Acoustically operable electrical switching circuits
GB2077011A (en) * 1980-05-27 1981-12-09 Yeldham Albert James A bedroom light control device
GB2161302A (en) * 1984-07-04 1986-01-08 Christopher Paul Northcott Sound activated light switch
GB2226170A (en) * 1988-11-15 1990-06-20 Waverlink Electronics Limited Sound sensitive electrical switch

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2355825A (en) * 1999-07-23 2001-05-02 Allan Marshall A lighting device operated by sound
GB2374185A (en) * 2001-04-05 2002-10-09 Jung Tsung Wei Vibration sensing assembly and controller
WO2011070336A1 (en) * 2009-12-11 2011-06-16 Benmore Ventures Limited Sound-actuated illumination circuit
US8952629B2 (en) 2009-12-11 2015-02-10 Benmore Ventures Limited Sound-actuated illumination circuit

Also Published As

Publication number Publication date
GB9026720D0 (en) 1991-01-30

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WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)