CN2485747Y

CN2485747Y - Electronic loudspeaker

Info

Publication number: CN2485747Y
Application number: CN 01237424
Authority: CN
Inventors: 邓志良; 苏翔
Original assignee: 苏祥华
Priority date: 2001-04-19
Filing date: 2001-04-19
Publication date: 2002-04-10
Anticipated expiration: 2011-04-19

Abstract

The utility model relates to a loud-hailer without polarity and contact, having the structural key points that a circuit comprises a multi-vibrator formed by a 555 time-base circuit, a trumpet driving loop, a switch driving amplifier for connecting the output end of the oscillator and the driving loop; the power input of the circuit is connected with a bridge rectifier and a voltage regulation filter; the capacitance charge and discharge electric circuit of the multi-vibrator consists of two leading diodes, forming two charge and discharge electric circuits with different time constants, making the frequency and the duty ratio of the oscillator be adjustable. The utility model has the advantages that the power supply has no polarity requirement, no mechanical contact and a long service time; the operating supply voltage has large scope, large loudness, pure musical quality; and the loudness and the musical quality are adjustable.

Description

Electronic horn

The utility model relates to a kind of nonpolarity contactless electronic horn, can be used for the signalling alarm equipment of the vehicles such as shipping vehicle.

The common electrical loudspeaker are to utilize solenoid to attract and release armature, cause the contact to disconnect and the connection circuit, cause the vibration of electric horn drive coil and drive the Loudspeaker diaphragm sounding, the about 300-500Hz of its frequency of operation, promptly the contact per second will be worked 300-500 time, and in order to guarantee the suction-combining force of coil, the contact will be by the big electric current of 1.5-5A, therefore the frequent open close contact that causes produces electric arc, and high temperature is the scaling loss contact then, so serviceable life is shorter.The prior art contactless electronic loudspeaker all adopts the simulated sound integrated circuit to produce sound-source signal and directly drive the horn loudspeaker sounding after power amplification, and tone is difficult to adjust, a little less than the volume, and widely used electric horn in the incompatible vehicle at present.

The purpose of this utility model provide a kind of nonpolarity contactless, tone color is pure, can regulate the electronic horn of tone and volume easily.

For achieving the above object, the utility model is achieved in that a kind of electronic horn, its circuit comprises a multivibrator that is made of 555 time base circuits, the switch drive amplifier of loudspeaker drive coil and connection oscillator output terminal and drive coil; The input end of this circuit is connected to bridge rectifier and pressure stabilization filter, the charging of described multivibrator and discharge resistance separate and are in parallel mutually, these two parallel resistance branch roads have been connected in series a diode respectively, the polarity of two diodes plays guiding function on the contrary, make two parallel branches form charge circuit and discharge loop respectively, 5 pin voltage controling ends of described 555 time base circuits are through decoupling capacitor ground connection.

The utility model has the advantages that: 1, do not have mechanical contact, long service life; 2, multivibrator is through voltage regulation filtering, frequency stabilization, during power-supply fluctuation, tone color remains unchanged, the working power scope big (during rated voltage 12VDC, input power range 10.5VDC-15.0VDC; During rated voltage 24VDC, input power range 21.0VDC-28.0VDC); 3, pulse duty factor is adjustable, and the suction of horn coil is improved, and vibrating diaphragm is operated in best operating point, and loudspeaker loudness is big; 4, power supply input circuit adopts bridge rectifier, and power input is nonpolarity, and user's power supply of arbitrarily plugging into can not damage the electronic horn circuit; 5, the voltage controling end of time base circuit has improved the circuit antijamming capability greatly through decoupling capacitor ground connection, uses under the condition of vibrating that is particluarly suitable for jolting; 6,555 time base circuits are structurally combined by mimic channel and digital circuit, and it is an one with analog functuion and logic function compatibility, under the situation of stable operating voltage, can produce accurate oscillation frequency.

The utility model is described in further detail below in conjunction with accompanying drawing:

Fig. 1 is the circuit theory diagrams of the utility model electronic horn.

Circuit shown in Figure 1 comprises switch drive amplifier, bridge rectifier, pressure stabilization filter and the decoupling capacitor of the multivibrator of an EDM Generator of Adjustable Duty Ratio that is made of 555 time base circuits, loudspeaker drive coil, connection oscillator output terminal and drive coil.

Direct supply is through D ₃～D ₆The bridge rectifier and the R that form ₄, DW, C ₃The pressure stabilization filter of forming, anodal 8 pin power ends and 4 pin preset ends with 555 time base circuits join, and negative pole and 1 pin earth terminal join, no matter power supply is a forward or reverse, bridge rectifier guarantees that circuit obtains positive polarity voltage; Even mains fluctuations, pressure stabilization filter also can make multivibrator obtain stable operating voltage, and produce accurate oscillation frequency.Divide two-way after 2 pin low triggering ends of time base circuit and 6 pin high-triggering ends join: the one tunnel through capacitor C ₁Ground connection, in addition～two the steering diode D in road ₁, D ₂And resistance R ₁, R ₂, R ₃The charge and discharge circuit that constitutes links to each other with positive source with 7 pin discharge ends respectively, because the time constant of charging circuit and discharge circuit is respectively (R ₁+ R ₂) C ₁And R ₃C ₁, change R ₂And R ₃Resistance value, just can obtain the cyclical signal of different oscillation frequency, different duty.Time base circuit 5 pin voltage controling ends are through decoupling capacitor C ₂Ground connection is to improve the circuit antijamming capability.3 pin output terminals of time base circuit are through current-limiting resistance R ₅And T ₁, T ₂, R ₆Switch drive amplifier and the loudspeaker drive coil formed are plugged into, and the periodicity rectangular wave pulse that multivibrator is exported amplifies the rear drive horn coil with certain frequency energized, promotes the vibrating membrane chatter, through the resonance of sound box, and the generation sound signal.

Behind the power connection, forward voltage is added on the circuit, because C ₁On voltage can not suddenly change, initial value is zero, so time base circuit is in SM set mode, blood transfusion is held and is put high level; Power supply passes through R ₁, D ₁, R ₂To C ₁C is worked as in charging ₁Charge to 2/3V _Cc(V _CcBe the time base circuit operating voltage) time, the inner high trigger comparator upset of time base circuit makes inner rest-set flip-flop set, and output terminal is put low level, and conducting internal discharge triode, makes C ₁Pass through R ₃, D ₂Discharge with the internal discharge triode; Work as C ₁When being discharged to 1/3Vcc, low trigger comparator upset resets rest-set flip-flop in the time base circuit, exports high level after paraphase again; And make the internal discharge triode end C ₁Begin charging again; Above process repeats, and goes round and begins again, and forms multivibrator, and output is rectangular pulse signal periodically, promotes sound horn through driving amplifier.

The electronic horn that this circuit constitutes is a monotone horn, if the loudspeaker of two different frequencies are made up, can produce the high and low mixing sound of high-quality.

This electronic circuit is through water-proofing treatment in addition, even yet normal sounding of water inlet loudspeaker can not damage electron device.

Claims

1, a kind of electronic horn, its circuit comprise the switch drive amplifier of a multivibrator that is made of 555 time base circuits, loudspeaker drive coil and connection oscillator output terminal and drive coil, it is characterized in that:

The input end of A, this circuit is connected to bridge rectifier and pressure stabilization filter;

The charging of B, described multivibrator and discharge resistance separate and are in parallel mutually, and these two parallel resistance branch roads have been connected in series a diode respectively, and the polarity of two diodes is opposite.

2, electronic horn as claimed in claim 1, the 5 pin voltage controling ends that it is characterized in that described 555 time base circuits are through capacity earth.