CN216600050U - Sound box protection circuit realized by discrete elements - Google Patents
Sound box protection circuit realized by discrete elements Download PDFInfo
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- CN216600050U CN216600050U CN202123164064.XU CN202123164064U CN216600050U CN 216600050 U CN216600050 U CN 216600050U CN 202123164064 U CN202123164064 U CN 202123164064U CN 216600050 U CN216600050 U CN 216600050U
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- triode
- relay
- resistor
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- loudspeaker
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- 239000003990 capacitor Substances 0.000 claims abstract description 34
- 230000003111 delayed effect Effects 0.000 abstract 1
- 230000002159 abnormal effect Effects 0.000 description 3
- 230000005236 sound signal Effects 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000003116 impacting effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
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Abstract
The utility model relates to a sound box protection circuit realized by discrete elements, belonging to the technical field of electronics. The protection circuit mainly comprises triodes Q1-Q5, a relay RL1, resistors R1-R4, a diode D1 and capacitors C1-C3. The resistors R1 and R2 and the capacitors C1 and C2 form an RC low-pass filter, once the RC low-pass filter detects that the power amplifier has direct current output, the corresponding triode is driven, and then the triode drives the relay RL1 to disconnect the loudspeaker box, so that the bass loudspeaker of the loudspeaker box is prevented from being damaged by direct current. When the loudspeaker is powered on, the relay RL1 is controlled by the capacitor C3 and the resistor R4 to switch on the loudspeaker in a delayed mode, and impact of the power amplifier on the loudspeaker at the moment of starting is avoided. This utility model, constitute by discrete component entirely, with low costs, and discrete component is withstand voltage higher, and is not fragile.
Description
Technical Field
The utility model relates to a sound box protection circuit realized by discrete elements, belonging to the technical field of electronics.
Background
The high-power sound power amplifier mostly adopts an OCL circuit form, and the output end adopts a direct coupling mode for output. When the power amplifier is in normal state, the output end of the power amplifier has 0V direct-current voltage to the ground, and only audio signals are output. However, when any sound channel of the power amplifier is abnormal, the output end of the sound channel may have a dc voltage output, and if the dc voltage is transmitted to the sound box, the coil of the woofer of the sound box will be heated, and the coil of the woofer may be deformed or blown, thereby damaging the woofer. Therefore, the sound box power amplifier is internally provided with a sound box protection circuit, and once the protection circuit detects that the power amplifier has direct-current voltage output, the connection between the sound box and the power amplifier is cut off, so that the bass loudspeaker of the sound box is prevented from being damaged. However, in the traditional sound box protection circuit, the integrated chip is responsible for abnormal detection, so that the cost is high, the voltage resistance is low, and the traditional sound box protection circuit is easy to damage.
SUMMERY OF THE UTILITY MODEL
In order to solve the above problems, the present invention provides a speaker protection circuit implemented by discrete components, wherein when it is detected that the output terminal of the power amplifier has a dc output, a relay in the protection circuit cuts off the connection between the power amplifier and the speaker, so as to achieve the purpose of protecting the woofer in the speaker. The protection circuit also has a starting time delay function, and the relay is used for connecting the power amplifier with the sound box after the power amplifier is started for a plurality of seconds, so that the impact on a loudspeaker of the sound box caused by the unstable voltage at the output end of the power amplifier at the moment of starting is avoided.
The adopted specific technical scheme is as follows:
a sound box protection circuit realized by discrete elements comprises triodes Q1-Q5, a relay RL1, resistors R1-R4, a diode D1, capacitors C1-C3, input ends L _ IN and R _ IN, and output ends L _ OUT and R _ OUT, wherein the input end L _ IN is connected to one end of the resistor R1 and one end of a left group of normally open switches of the relay RL1, and the input end R _ IN is connected to one end of the resistor R2 and one end of a right group of normally open switches of the relay RL 1; the anode of the capacitor C1 is connected to the other end of the resistor R1, the other end of the resistor R2 and one end of the resistor R3, the cathode of the capacitor C2 is connected to the cathode of the capacitor C2, and the anode of the capacitor C2 is grounded; the base electrode of the triode Q1 is connected to the other end of the resistor R3 and the base electrode of the triode Q3, the emitting electrode is grounded, and the collecting electrode is connected to the base electrode of the triode Q2; the emitter of the triode Q2 is connected with-5V, the collector of the triode Q2 is connected with one end of a resistor R4, the anode of a capacitor C3, the collector of the triode Q3 and the base of the triode Q4, the other end of the resistor R4 is connected with +5V, and the cathode of the capacitor C3 and the emitter of the triode Q3 are both grounded; the collector of the triode Q4 is connected with +5V, and the emitter is connected with the base of the triode Q5; the emitter of the triode Q5 is grounded, the collector of the triode Q5 is connected with the anode of the diode D1 and one end of the coil of the relay RL1, and the other end of the coil of the relay RL1 and the cathode of the diode D1 are both connected with + 5V; the output end L _ OUT is connected to the other end of the left group of normally open switches of the relay RL1, and the output end R _ OUT is connected to the other end of the right group of normally open switches of the relay RL 1.
The beneficial effects of the utility model are as follows: the protection circuit can prevent the power amplifier from impacting the loudspeaker of the sound box when the power amplifier is powered on, and can cut off the connection between the power amplifier and the sound box when the power amplifier outputs abnormal direct current, thereby achieving the purpose of protecting the woofer of the sound box. The circuit is composed of discrete elements, so that the cost is low, and the elements are high in voltage resistance and not easy to damage.
Drawings
Fig. 1 shows an embodiment of the present invention.
Detailed Description
The utility model is further described below with reference to the accompanying drawings.
The specific circuit is as shown IN fig. 1, the circuit of the sound box protection circuit realized by discrete elements comprises triodes Q1-Q5, a relay RL1, resistors R1-R4, a diode D1, capacitors C1-C3, input ends L _ IN and R _ IN, and output ends L _ OUT and R _ OUT, wherein the input end L _ IN is connected to one end of the resistor R1 and one end of a left group of normally open switches of the relay RL1, and the input end R _ IN is connected to one end of the resistor R2 and one end of a right group of normally open switches of the relay RL 1; the anode of the capacitor C1 is connected to the other end of the resistor R1, the other end of the resistor R2 and one end of the resistor R3, the cathode of the capacitor C2 is connected to the cathode of the capacitor C2, and the anode of the capacitor C2 is grounded; the base electrode of the triode Q1 is connected to the other end of the resistor R3 and the base electrode of the triode Q3, the emitting electrode is grounded, and the collecting electrode is connected to the base electrode of the triode Q2; the emitter of the triode Q2 is connected with-5V, the collector of the triode Q2 is connected with one end of a resistor R4, the anode of a capacitor C3, the collector of the triode Q3 and the base of the triode Q4, the other end of the resistor R4 is connected with +5V, and the cathode of the capacitor C3 and the emitter of the triode Q3 are both grounded; the collector of the triode Q4 is connected with +5V, and the emitter is connected with the base of the triode Q5; the emitter of the triode Q5 is grounded, the collector of the triode Q5 is connected with the anode of the diode D1 and one end of the coil of the relay RL1, and the other end of the coil of the relay RL1 and the cathode of the diode D1 are both connected with + 5V; the output end L _ OUT is connected to the other end of the left group of normally open switches of the relay RL1, and the output end R _ OUT is connected to the other end of the right group of normally open switches of the relay RL 1.
When the power amplifier is applied, the input ends L _ IN and R _ IN are respectively connected to the left sound channel and the right sound channel of the power amplifier for output, the output ends L _ OUT and R _ OUT are respectively connected to the anodes of the left sound box and the right sound box, and the cathodes of the left sound box and the right sound box are connected to the common ground.
The resistors R1 and R2 and the capacitors C1 and C2 form an RC low-pass filter, wherein the capacitor C1 and the capacitor C2 are connected in series, and two polar capacitors are combined into an electrodeless capacitor so as to resist positive or negative direct-current voltage output by the power amplifier. The formed RC low-pass filter filters out the alternating current audio signal output by the power amplifier and leaves a direct current signal. When the power amplifier is normal, only the alternating current audio signal is output, the direct current output voltage is about 0V, and the output voltage of the RC low-pass filter is also about 0V. And once the left channel or the right left channel of the power amplifier outputs direct current, the RC low-pass filter detects the direct current.
If the RC low-pass filter detects positive direct-current voltage and the voltage amplitude exceeds +0.6V, the triode Q3 is conducted; if a negative dc voltage is detected and the voltage level is below-0.6V, transistor Q1 will turn on, which in turn drives transistor Q2 to turn on. No matter the transistor Q2 or the transistor Q3 is conducted, the transistors Q4 and Q5 are cut off, the relay RL1 is released, the connection between the power amplifier and the sound box is cut off, and therefore the purpose of protecting the bass loudspeaker in the sound box is achieved.
When the power is switched on, the +5V charges the capacitor C3 through the resistor R4, the voltage of the capacitor C3 gradually rises from 0V, and when the voltage of the capacitor C3 rises to about +1V, the triodes Q4 and Q5 start to be conducted; when the voltage of the capacitor C3 rises to about +1.4V, the triode Q5 is in saturated conduction, the coil of the relay RL1 is driven by the voltage close to 5V, the relay RL1 is pulled in, the connection between the power amplifier and the sound box is switched on, and the sound box starts to work. From the power-on state to the normal operation of the sound box, the delay time length is determined by the parameters of the capacitor C3 and the resistor R4, and the longer the time constant R4C3 is, the longer the delay time length is. The loudspeaker box is powered on every time, the time delay is carried out for several seconds, and the impact of the power amplifier on the loudspeaker in the loudspeaker box at the moment of power-on is avoided.
Claims (1)
1. The utility model provides a sound box protection circuit that discrete component realized which characterized by: the circuit comprises triodes Q1-Q5, a relay RL1, resistors R1-R4, a diode D1, capacitors C1-C3, input ends L _ IN and R _ IN, and output ends L _ OUT and R _ OUT, wherein the input end L _ IN is connected to one end of the resistor R1 and one end of a left group of normally open switches of the relay RL1, and the input end R _ IN is connected to one end of the resistor R2 and one end of a right group of normally open switches of the relay RL 1; the anode of the capacitor C1 is connected to the other end of the resistor R1, the other end of the resistor R2 and one end of the resistor R3, the cathode of the capacitor C2 is connected to the cathode of the capacitor C2, and the anode of the capacitor C2 is grounded; the base electrode of the triode Q1 is connected to the other end of the resistor R3 and the base electrode of the triode Q3, the emitting electrode is grounded, and the collecting electrode is connected to the base electrode of the triode Q2; the emitter of the triode Q2 is connected with-5V, the collector of the triode Q2 is connected with one end of a resistor R4, the anode of a capacitor C3, the collector of the triode Q3 and the base of the triode Q4, the other end of the resistor R4 is connected with +5V, and the cathode of the capacitor C3 and the emitter of the triode Q3 are both grounded; the collector of the triode Q4 is connected with +5V, and the emitter is connected with the base of the triode Q5; the emitter of the triode Q5 is grounded, the collector of the triode Q5 is connected with the anode of the diode D1 and one end of the coil of the relay RL1, and the other end of the coil of the relay RL1 and the cathode of the diode D1 are both connected with + 5V; the output end L _ OUT is connected to the other end of the left group of normally open switches of the relay RL1, and the output end R _ OUT is connected to the other end of the right group of normally open switches of the relay RL 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202123164064.XU CN216600050U (en) | 2021-12-16 | 2021-12-16 | Sound box protection circuit realized by discrete elements |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202123164064.XU CN216600050U (en) | 2021-12-16 | 2021-12-16 | Sound box protection circuit realized by discrete elements |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN216600050U true CN216600050U (en) | 2022-05-24 |
Family
ID=81612462
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202123164064.XU Expired - Fee Related CN216600050U (en) | 2021-12-16 | 2021-12-16 | Sound box protection circuit realized by discrete elements |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN216600050U (en) |
-
2021
- 2021-12-16 CN CN202123164064.XU patent/CN216600050U/en not_active Expired - Fee Related
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20220524 |