CN202334838U - Frequency-modulation wireless microphone being made of variable-capacitance diode - Google Patents
Frequency-modulation wireless microphone being made of variable-capacitance diode Download PDFInfo
- Publication number
- CN202334838U CN202334838U CN2011204971590U CN201120497159U CN202334838U CN 202334838 U CN202334838 U CN 202334838U CN 2011204971590 U CN2011204971590 U CN 2011204971590U CN 201120497159 U CN201120497159 U CN 201120497159U CN 202334838 U CN202334838 U CN 202334838U
- Authority
- CN
- China
- Prior art keywords
- resistance
- circuit
- capacitance diode
- frequency
- variable capacitance
- 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 - Fee Related
Links
Images
Landscapes
- Transmitters (AREA)
Abstract
The utility model relates to a frequency-modulation wireless microphone being made of a variable-capacitance diode, which consists of a 6V direct-current power source DC, an audio pickup and audio amplifying circuit, an amplitude stabilizing circuit, a variable-capacitance diode biasing circuit, an oscillating circuit and a high-frequency amplification circuit. Due to adoption of the frequency-modulation wireless microphone being made of the variable-capacitance diode, the weaknesses of multiple frequency-modulation wireless microphone by changing the capacitance between a base electrode and a transmission electrode of a transistor to realize the frequency modulation that parasitic amplitude modulation phenomenon is easy to produce, the harmonic composition is multiple and the like can be overcome. The capacitance of the variable-capacitance diode is varied along the variation of an audio signal, and then the audio signal is loaded into the oscillating circuit to realize the frequency modulation. The transmitter is free from an external antenna, so great convenience can be brought to the user.
Description
Technical field
The utility model belongs to electronic technology and communication technical field, is the frequency modulation wireless microphone of making about a kind of variable capacitance diode.
Background technology
The operation principle of most frequency modulation wireless microphones is through changing electric capacity realization frequency modulation between transistorized base stage and the emitter on the market; When the sound voltage signal is added to transistorized base stage; Electric capacity can change along with sound voltage signal size synchronously between transistorized base stage and the emitter; Transistorized tranmitting frequency is changed, and then realize modulation frequency.
The core parts of the utility model are variable capacitance diodes, and audio signal makes the capacity of variable capacitance diode change along with the variation of audio voltage, then audio signal are loaded in the oscillating circuit, thereby have realized frequency modulation.This reflector need not external antenna, greatly facilitates user's use.
Below specify frequency modulation wireless microphone that this variable capacitance diode makes related relevant technologies content in manufacturing process.
The utility model content
Goal of the invention and beneficial effect: the frequency modulation work that the utility model purpose has been to overcome most frequency modulation wireless microphones is to realize frequency modulation through changing between transistorized base stage and the emitter electric capacity; This mode of frequency regulation exists and be prone to produce the parasitic amplitude modulation phenomenon, and defective such as harmonic components is many.The utility model utilizes variable capacitance diode, and the capacity of variable capacitance diode is changed along with the variation of audio signal, then audio signal is loaded in the oscillating circuit, thereby realizes frequency modulation.This reflector need not external antenna, greatly facilitates user's use.This frequency-modulated transmitter also has simple, the characteristics such as cost is low, dependable performance of making.
The circuit working principle: this frequency modulation wireless launcher is made up of low-frequency amplifier circuit, low-pass filter circuit, variable capacitance diode and biasing circuit, vibration and high-frequency amplifier circuit.After the audio signal that Electret condenser microphone MIC produces is amplified by PNP silicon transistor BG1; Deliver to variable capacitance diode D1; Its capacity is changed along with the variation of audio signal; The oscillating circuit of then forming through PNP silicon transistor BG2 carries out frequency modulation, frequency-modulatd radiofrequency signal by oscillator coil L2 to aerial radiation.This oscillating circuit has been eliminated and has been adopted the junction capacitance frequency modulation of PNP silicon transistor to be easy to generate the parasitic amplitude modulation phenomenon.
Technical scheme: the frequency modulation wireless microphone that variable capacitance diode is made, by 6V DC power supply DC, audio frequency picks up and audio amplifier circuit, fixed amplitude circuit, variable capacitance diode biasing circuit, oscillating circuit and high-frequency amplifier circuit are formed, its characteristic comprises:
Audio frequency picks up and audio amplifier circuit: the base stage of PNP silicon transistor BG1 links to each other with an end of the negative pole of electrochemical capacitor C1, resistance R 1; The positive pole of electrochemical capacitor C1 connects the output of Electret condenser microphone MIC; The shell connection circuit ground GND of Electret condenser microphone MIC, the anodal VCC of the other end connection circuit of resistance R 1, the collector electrode of PNP silicon transistor BG1 connects the positive pole of electrochemical capacitor C2 and an end of resistance R 2; The anodal VCC of the other end connection circuit of resistance R 2, the emitter connection circuit ground GND of PNP silicon transistor BG1;
Fixed amplitude circuit: the negative pole of electrochemical capacitor C2 links to each other with an end of resistance R 3 and the end of inductance coil L1, the anodal VCC of the other end connection circuit of resistance R 3, the negative pole of another termination variable capacitance diode D1 of inductance coil L1;
The variable capacitance diode biasing circuit: the positive pole of variable capacitance diode D1 links to each other with an end of resistance R 4 and an end of resistance R 5, the anodal VCC of the other end connection circuit of resistance R 4, the other end connection circuit ground GND of resistance R 5;
Oscillating circuit and high-frequency amplifier circuit: the base stage of PNP silicon transistor BG2 links to each other with an end of an end of resistance R 6 and resistance R 7; The anodal VCC of the other end connection circuit of resistance R 6; The other end connection circuit ground GND of resistance R 7; The collector electrode of PNP silicon transistor BG2 links to each other with the end of an end of capacitor C 4, oscillator coil L2, an end of capacitor C 3, the anodal VCC of the other end connection circuit of the other end of capacitor C 4, oscillator coil L2, the negative pole of another termination variable capacitance diode D1 of capacitor C 3; The emitter of PNP silicon transistor BG2 links to each other with an end of resistance R 8, the other end connection circuit ground GND of resistance R 8.
The positive pole of 6V DC power supply DC links to each other with circuit anode VCC, and the negative pole of 6V DC power supply DC links to each other with circuit ground GND.
Description of drawings
Accompanying drawing 1 is the embodiment circuit working schematic diagram that the utility model provides the frequency modulation wireless microphone of a variable capacitance diode making; Require the shell connection circuit ground GND of Electret condenser microphone MIC.
Embodiment
The circuit working schematic diagram of the frequency modulation wireless microphone of making according to variable capacitance diode shown in the accompanying drawing 1 and the components and parts specification requirement enforcement of description of drawings and the following stated can realize the utility model.
The selection of components and parts and technical parameter thereof
BG1 is the PNP silicon transistor, and model 2SC9014 requires β >=200; BG2 is the PNP silicon transistor, requires models such as 2SC9018, characteristic frequency requirement >=350MHz; D1 is a variable capacitance diode;
Resistance all uses RTX-1/8W type metalfilmresistor, the resistance 470K Ω of resistance R 1, resistance 800 Ω of resistance R 2; The resistance 100K Ω of resistance R 3, the resistance 22K Ω of resistance R 4, resistance R 5 resistance 56K Ω; The resistance 12K Ω of resistance R 6, the resistance 4.7K Ω of resistance R 7, resistance 330 Ω of resistance R 8;
C1～C2 is a CD11-25V type electrochemical capacitor, and capacity is respectively 22 μ F, 2.2 μ F;
C3, C4 are the high-quality ceramic disc capacitor, and capacity is 5.1PF;
MIC is a microphone, selects the Electret condenser microphone of two lead-out terminals for use, its shell connection circuit ground GND.
The making of components and parts
When making the circuit of this device, require circuit board to use high-frequency signal loss circlet epoxy resins plate.
Inductance coil L1 puts down around 100 circles greater than the fixed carbon resister higher slice of 120K Ω in 1/4W, resistance with the enamelled wire of ￠ 0.25～0.3mm, and two joints are welded in the two ends of 100K Ω resistance.
Oscillator coil L2 is with the enamelled wire of ￠ 1mm, and flat around 5 circles on ￠ 8mm pole, it is hollow that tread flaking becomes.
The adjustment of circuit
This wireless microphone connects the 6V DC power supply, and measuring PNP silicon transistor BG1 emitter should have the voltage of 0.7～0.8V over the ground, otherwise should adjust resistance R 1; Measuring PNP silicon transistor BG2 emitter should have the direct voltage of 1.8～2V over the ground, if should not adjust resistance R 6 in scope; Survey the variable capacitance diode two ends again and answer no-voltage, or the voltage difference at variable capacitance diode two ends if its two ends pressure reduction is bigger than normal, should be adjusted resistance R 3 or resistance R 4 less than 0.28V.
After the foregoing adjustment finished, with the receivable signal to the reflector emission of FM receiver, reflector was away from the distance more than the FM receiver 15m; If can not receive the signal that reflector sends, can adjust oscillator coil L2, stretching oscillator coil L2 fundamental frequency rises; Compressional oscillation coil L2 fundamental frequency descends; Make the frequency of reflector emission avoid local radio station, can reliable reception be as the criterion again, this reflector need not external antenna.After debugging was good, it is solid that oscillator coil L2 adopts the high-quality high frequency to seal with wax.
Electret is in microphone MIC input audio signal, and careful adjustment exchanges the resistance of the potentiometer RP in the negative feedback loop, makes audio signal undistorted being as the criterion when max volume.Audio input end is connected to the audio output of television set, and the acoustical quality that it is clear, stable and the signal of FM radio station are almost as broad as long.
Wireless microphone in its size suitable plastic of packing into, can't use can after finishing with the adjustment of beginning a project.When supplying power with 6V, its transmitting range can reach more than the 100m, and when wireless microphone was used the 5V power supply instead, transmitting range was about 40m.
Claims (2)
1. the frequency modulation wireless microphone made of a variable capacitance diode, by 6V DC power supply DC, audio frequency picks up and audio amplifier circuit, fixed amplitude circuit, variable capacitance diode biasing circuit, oscillating circuit and high-frequency amplifier circuit are formed, its characteristic comprises:
Audio frequency pick up and audio amplifier circuit in the base stage of PNP silicon transistor BG1 link to each other with the negative pole of electrochemical capacitor C1, an end of resistance R 1; The positive pole of electrochemical capacitor C1 connects the output of Electret condenser microphone MIC; The shell connection circuit ground GND of Electret condenser microphone MIC; The anodal VCC of the other end connection circuit of resistance R 1; The collector electrode of PNP silicon transistor BG1 connects the positive pole of electrochemical capacitor C2 and an end of resistance R 2, the anodal VCC of the other end connection circuit of resistance R 2, the emitter connection circuit ground GND of PNP silicon transistor BG1;
The negative pole of electrochemical capacitor C2 in the fixed amplitude circuit links to each other with the end of an end of resistance R 3 and inductance coil L1, the anodal VCC of the other end connection circuit of resistance R 3, the negative pole of another termination variable capacitance diode D1 of inductance coil L1;
The positive pole of variable capacitance diode D1 in the variable capacitance diode biasing circuit links to each other with an end of an end of resistance R 4 and resistance R 5, the anodal VCC of resistance R 4 other end connection circuits, resistance R 5 other end connection circuit ground GND;
The base stage of PNP silicon transistor BG2 links to each other with an end of resistance R 6 and an end of resistance R 7 in oscillating circuit and the high-frequency amplifier circuit; The anodal VCC of the other end connection circuit of resistance R 6; The other end connection circuit ground GND of resistance R 7; The collector electrode of PNP silicon transistor BG2 links to each other with the end of an end of capacitor C 4, oscillator coil L2, an end of capacitor C 3, the anodal VCC of the other end connection circuit of the other end of capacitor C 4, oscillator coil L2, the negative pole of another termination variable capacitance diode D1 of capacitor C 3; The emitter of PNP silicon transistor BG2 links to each other with an end of resistance R 8, the other end connection circuit ground GND of resistance R 8.
2. the frequency modulation wireless microphone that variable capacitance diode according to claim 1 is made, it is characterized in that: the positive pole of 6V DC power supply DC links to each other with circuit anode VCC, and the negative pole of 6V DC power supply DC links to each other with circuit ground GND.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011204971590U CN202334838U (en) | 2011-12-04 | 2011-12-04 | Frequency-modulation wireless microphone being made of variable-capacitance diode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011204971590U CN202334838U (en) | 2011-12-04 | 2011-12-04 | Frequency-modulation wireless microphone being made of variable-capacitance diode |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202334838U true CN202334838U (en) | 2012-07-11 |
Family
ID=46446800
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011204971590U Expired - Fee Related CN202334838U (en) | 2011-12-04 | 2011-12-04 | Frequency-modulation wireless microphone being made of variable-capacitance diode |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202334838U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102448001A (en) * | 2011-12-04 | 2012-05-09 | 李宁杭 | Frequency modulation wireless microphone made of varactor diode |
-
2011
- 2011-12-04 CN CN2011204971590U patent/CN202334838U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102448001A (en) * | 2011-12-04 | 2012-05-09 | 李宁杭 | Frequency modulation wireless microphone made of varactor diode |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102355618A (en) | Modulated wave wireless microphone | |
| CN102231633A (en) | Wireless frequency modulation transmitter manufactured by using varactor diode | |
| CN202957973U (en) | High-performance amplitude-modulation wireless microphone | |
| CN202059395U (en) | Frequency modulation wireless transmitter made from varactor diode | |
| CN202334838U (en) | Frequency-modulation wireless microphone being made of variable-capacitance diode | |
| CN202737853U (en) | FM transmitter with low power and high sensitivity | |
| CN102448001A (en) | Frequency modulation wireless microphone made of varactor diode | |
| CN102595291A (en) | Minitype frequency modulation wireless microphone | |
| CN202750078U (en) | FM transmitter with low power and high sensitivity | |
| CN202143205U (en) | Amplitude-modulated wave wireless microphone | |
| CN201571045U (en) | Voice wireless transmission device | |
| CN202261716U (en) | Micro frequency modulation wireless microphone with battery | |
| CN102158776A (en) | Frequency-modulation wireless microphone made of single battery | |
| CN201957211U (en) | FM wireless microphone made of single battery | |
| CN202334880U (en) | Frequency modulation wireless microphone with high-performance integrated circuit | |
| CN202696583U (en) | Multi-functional minitype frequency modulation emitter | |
| CN203180902U (en) | A frequency modulation transmitter with strong anti-interference performance | |
| CN202931294U (en) | High sensitivity FM transmitter | |
| CN103096212A (en) | Low-voltage single-tube frequency modulation wireless microphone | |
| CN103532572A (en) | Low-power high-sensitivity FM transmitter | |
| CN202334835U (en) | Frequency modulation wireless microphone manufactured with integrated circuit | |
| CN203193616U (en) | Low-power high-sensitivity frequency band transmitter | |
| CN210670431U (en) | Wireless microphone | |
| CN202334879U (en) | Simple and reliable frequency modulation wireless microphone | |
| CN102395064A (en) | Miniature frequency-modulation wireless microphone with one battery |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120711 Termination date: 20121204 |