GB1493927A - Audio-frequency oscillators - Google Patents

Audio-frequency oscillators

Info

Publication number
GB1493927A
GB1493927A GB5422174A GB5422174A GB1493927A GB 1493927 A GB1493927 A GB 1493927A GB 5422174 A GB5422174 A GB 5422174A GB 5422174 A GB5422174 A GB 5422174A GB 1493927 A GB1493927 A GB 1493927A
Authority
GB
United Kingdom
Prior art keywords
frequency
audio
oscillator
transistor
few
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.)
Expired
Application number
GB5422174A
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.)
ELECTRONIC CONCEPTS Ltd
Original Assignee
ELECTRONIC CONCEPTS 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 ELECTRONIC CONCEPTS Ltd filed Critical ELECTRONIC CONCEPTS Ltd
Priority to GB5422174A priority Critical patent/GB1493927A/en
Publication of GB1493927A publication Critical patent/GB1493927A/en
Expired legal-status Critical Current

Links

Classifications

    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01M—CATCHING, TRAPPING OR SCARING OF ANIMALS; APPARATUS FOR THE DESTRUCTION OF NOXIOUS ANIMALS OR NOXIOUS PLANTS
    • A01M29/00—Scaring or repelling devices, e.g. bird-scaring apparatus
    • A01M29/16—Scaring or repelling devices, e.g. bird-scaring apparatus using sound waves
    • A01M29/18—Scaring or repelling devices, e.g. bird-scaring apparatus using sound waves using ultrasonic signals
    • 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
    • H03K3/35—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar semiconductor devices with more than two PN junctions, or more than three electrodes, or more than one electrode connected to the same conductivity region
    • H03K3/351—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar semiconductor devices with more than two PN junctions, or more than three electrodes, or more than one electrode connected to the same conductivity region the devices being unijunction transistors
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03L—AUTOMATIC CONTROL, STARTING, SYNCHRONISATION, OR STABILISATION OF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES
    • H03L7/00—Automatic control of frequency or phase; Synchronisation

Abstract

1493927 Unijunction transistor oscillators ELECTRONIC CONCEPTS Ltd 27 Feb 1976 [16 Dec 1974] 54221/74 Heading H3T [Also in Divisions Al and G5] In an audio-frequency oscillator such as for repelling mosquitoes including a unijunction transistor relaxation oscillator 1 having a time constant circuit including a capacitor 5 and a charging resistance 6, 8, the charging resistance includes a transistor conduction path 8 which is controlled by a circuit 9-13 having a cylically varying value whereby the frequency of the audible output is cyclically varied in value. As shown the output from a unijunction transistor relaxation oscillator 9-13 of a few Hz controls the charging resistance of transistor 8 so that the audio frequency tone of a few kHz from a loud-speaker 2 of the oscillator 1 is swept cyclically at this same frequency of a few Hz.
GB5422174A 1974-12-16 1974-12-16 Audio-frequency oscillators Expired GB1493927A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB5422174A GB1493927A (en) 1974-12-16 1974-12-16 Audio-frequency oscillators

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB5422174A GB1493927A (en) 1974-12-16 1974-12-16 Audio-frequency oscillators

Publications (1)

Publication Number Publication Date
GB1493927A true GB1493927A (en) 1977-11-30

Family

ID=10470322

Family Applications (1)

Application Number Title Priority Date Filing Date
GB5422174A Expired GB1493927A (en) 1974-12-16 1974-12-16 Audio-frequency oscillators

Country Status (1)

Country Link
GB (1) GB1493927A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2452248A1 (en) * 1979-03-30 1980-10-24 Saimpex Sa Protection against undesirable insects or animals - is provided by emission of particular modulated or unmodulated ultrasonic frequency
GB2211649A (en) * 1987-10-27 1989-07-05 Pal Int Ltd Bird dispersal apparatus

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2452248A1 (en) * 1979-03-30 1980-10-24 Saimpex Sa Protection against undesirable insects or animals - is provided by emission of particular modulated or unmodulated ultrasonic frequency
GB2211649A (en) * 1987-10-27 1989-07-05 Pal Int Ltd Bird dispersal apparatus
GB2211649B (en) * 1987-10-27 1991-11-27 Pal Int Ltd Bird dispersal apparatus

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Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee