CN2476911Y - Impedance Converter for Electronic Condenser Microphone - Google Patents

Abstract

An impedance converter of electronic capacitance microphone includes a transistor, a resistor connected with gate and source terminal and a group of filters connected with drain and source terminals of the transistor.

Description

Impedance Converter for Electronic Condenser Microphone

The utility model relates to a loudspeaker, in particular to an impedance converter of an electronic condenser microphone which has a small volume and is installed in a condenser microphone so as to improve the quality of sound reception.

By the way, with the rapid changes in science and technology, all kinds of electronic products need to be smaller in size to increase consumers' interest in buying, which can be changed by devices that generally use recorders, players or radio signals. Peep one, two. Because people often use a microphone with a loudspeaker device to increase the volume in multiple occasions, or use the microphone to store the sound in other devices, as a means of reviewing in the future, in order to make such devices easy to carry and use, Therefore, the trend of miniaturization has become more and more obvious.

However, among all kinds of microphones, the condenser microphone is the most compact. Because it occupies a small volume, it can simplify the functional circuit and achieve the design of a miniaturized radio device. The condenser microphone can be distinguished according to different usage conditions. Microphones with various functions, that is, omnidirectional, unidirectional, and close-talking condenser microphones. The main structure of the microphone is shown in Figure 3, including:

An induction unit (60), which can receive sound waves and convert them into voltage signals;

an impedance converter (50), which is connected to the output end of the sensing unit (60);

After the induction unit (60) receives the sound wave, the power of the signal is increased through the impedance converter (50), so that the condenser microphone outputs a better signal. Since the induction unit (60) is more sensitive, it will be affected by the surrounding noise and generate noise, so the operator connects a noise filter unit (70) to the output of the impedance converter (50) to filter out the noise. Noise from the microphone. However, in the present manufacture of the noise filter unit (70) of the above-mentioned condenser microphone, a filter capacitor is still added to the output end of the integrated circuit of the impedance converter (50) to achieve the purpose of filtering, but this manufacturing process brings the following shortcoming:

1. The volume cannot be further reduced: because the microphone circuit has a large number of components (such as capacitors, impedance converters, etc.), the overall volume cannot be miniaturized.

2. Small scope of application: Due to the excessive use of necessary components, the size cannot be reduced, which relatively limits the scope of application of the microphone.

3. Time-consuming to manufacture: Due to the large number of circuit components, manufacturing this structure is labor-intensive and time-consuming.

Therefore, the main purpose of the present invention is to provide an impedance converter that achieves better sound quality with a smaller volume and is easy to manufacture and implement for a condenser microphone.

The main technical means used to achieve the above-mentioned purpose is to connect the above-mentioned impedance converter to the output end of an induction unit, which includes:

An impedance converter of an electronic condenser microphone, characterized in that it comprises:

field effect transistor (FET);

A resistor is connected between the gate and the source of the field effect transistor;

A filtering unit, the two ends of which are respectively connected to the drain and the source of the field effect transistor.

The purpose of this utility model can also be further realized by the following technical measures.

In the impedance converter of the aforementioned electronic condenser microphone, the filter unit is two capacitors connected in parallel.

In the impedance converter of the aforementioned electronic condenser microphone, a diode is connected in parallel with the resistor, the anode of the diode is connected to the source of the field effect transistor, and the cathode is connected to the gate of the field effect transistor.

The impedance converter of the aforementioned electronic condenser microphone, wherein the impedance converter can be implemented in a chip.

The above structure is to implement the filter and the impedance converter in the same chip, so that the chip can have both impedance conversion and filtering functions, not only can the signal received by the sensing unit increase the output power, but also can obtain low noise The output signal is produced by using this integrated circuit in a condenser microphone, which can effectively reduce the size of the microphone, and can also save the disadvantages of complicated steps and long manufacturing hours.

In order to further understand the technical content, characteristics and effects of the present utility model, the following preferred embodiments are exemplified, and detailed descriptions are as follows in conjunction with the accompanying drawings:

Fig. 1 is an implementation circuit diagram of the utility model.

Fig. 2 is a schematic block diagram of an actual operation of the utility model.

FIG. 3 is a block diagram of a conventional condenser microphone.

The utility model is an impedance converter which is easy to be implemented in a condenser microphone and has a filter function, as shown in Fig. 1, the impedance converter (11) includes:

field effect transistor Q1;

a resistor R1 connected between the gate and the source of the field effect transistor Q1;

A filter unit (110), which is two parallel capacitors C1 and C2, wherein the two ends of the capacitors C1 and C2 are respectively connected to the drain and source of the field effect transistor Q1, and the other two ends of the parallel capacitors C1 and C2 are terminals A and B .

The above-mentioned circuit prevents the gate of the field effect transistor Q1 from directly introducing current into the source, so a reverse-biased diode D1 is connected between the gate and the source of the field-effect transistor Q1, wherein the cathode of the reverse-biased diode D1 is connected to the source. The gate of the field effect transistor Q1 is connected, and the anode thereof is connected to the source of the field effect transistor Q1.

As shown in Figure 2 is the implementation circuit diagram of the impedance converter (11), wherein the input terminal C of the impedance converter (11) is connected to the output end of an induction unit (10), when the induction unit (10) receives the sound signal Afterwards, the impedance matching is achieved through the impedance converter (11) to improve the output power effect, and the impedance converter (11) has a filtering function, so the noise of the received sound wave can be filtered out to retain a clear sound signal.

As can be seen from the above, the utility model can make the microphone have the following advantages because of improving the set impedance converter in the microphone:

1. Good sound quality: use the filter unit to filter out the noise of the sound signal.

2. Small size: Since the impedance converter and filter unit of the microphone can be manufactured on a semiconductor chip, the volume of the microphone can be effectively reduced.

3. It is easy to manufacture. Because the impedance converter has a filtering function, there is no need to connect an external filtering circuit on the circuit board, which can reduce the design of circuit lines, reduce the number of manufacturing components and facilitate implementation.

For this reason, the capacitive microphone created in this invention is not only better in structural design, but also has remarkable efficacy, which is indeed in line with the industrial use value, and meets the novelty, creativity, and practical patent requirements of applying for a new patent, so Apply according to law.

Claims (4)

1. An impedance converter of an electronic condenser microphone, characterized in that, comprising: A transistor is a field effect transistor; A resistor is connected between the gate and the source of the field effect transistor; A filtering unit, the two ends of which are respectively connected to the drain and the source of the field effect transistor. 2. The impedance converter of the electronic condenser microphone according to claim 1, wherein the filter unit is two capacitors connected in parallel. 3. The impedance converter of the electronic condenser microphone according to claim 1 or 2, wherein the resistor is connected in parallel with a diode, the anode of the diode is connected to the source of the field effect transistor, and its cathode is connected to the source of the field effect transistor. Gate connection for field effect transistors. 4. The impedance converter of the electronic condenser microphone according to claim 3, wherein the impedance converter can be implemented in a chip.

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