CN202696541U - Audio frequency amplifier system based on electricity supply of computer USB (universal serial bus) power supply and integration of USB sound card - Google Patents
Audio frequency amplifier system based on electricity supply of computer USB (universal serial bus) power supply and integration of USB sound card Download PDFInfo
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- CN202696541U CN202696541U CN 201220263356 CN201220263356U CN202696541U CN 202696541 U CN202696541 U CN 202696541U CN 201220263356 CN201220263356 CN 201220263356 CN 201220263356 U CN201220263356 U CN 201220263356U CN 202696541 U CN202696541 U CN 202696541U
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Abstract
The utility model provides an audio frequency amplifier system based on the electricity supply of a computer USB (universal serial bus) power supply and the integration of a USB sound card. The audio frequency amplifier system comprises a detection protection circuit, a DC/DC (direct current/direct current) power supply, an audio frequency amplification circuit, a battery charge/discharge and excess voltage protection circuit, a transient energy storage capacitor, a USB sound card digital audio frequency input circuit and a fore amplification circuit; the input of the USB power supply is respectively connected with the DC/DC power supply and the battery charge/discharge and excess voltage protection circuit through the detection protection circuit; the USB sound card digital audio frequency input circuit is output to volume control through the fore amplification circuit; an audio signal is input to the audio frequency amplification circuit through the volume control; an output end of the battery charge/discharge and excess voltage protection circuit supplies electricity for the audio frequency amplification circuit through the DC/DC power supply; and meanwhile, the battery charge/discharge and excess voltage protection circuit is connected with a battery pack. By using the audio frequency amplifier system, through increasing battery energy storage, the continuous output time under the same power level is prolonged greatly, and furthermore, the output power is greatly promoted in a condition that the original transient output time is guaranteed.
Description
Technical field
The utility model relates to the sound equipment field, relates in particular to a kind of audio-frequency amplifier system based on computer USB Power supply and the integration of USB sound card.
Background technology
Along with USB interface popularizing in computer, the multimedia play equipment system is also more and more, particularly directly uses the USB sound card as the output of power amplifier, to replace computer sound card.Because standard usb interface limits, the output voltage of its interface is+5V, electric current is 500mA to the maximum, namely the continuous limit power that can export of this interface is 2.5 watts, yet for music playing system, peak value (transient state) rated power of general music signal output and the ratio of its average output power are about 8:1, shown in 1, the power source of an energy continuous wave output 2.5W can offer the peak power about the about maximum 20W of music playing system, how to satisfy such condition?
Existing solution is with USB interface+5V power acquisition DC-DC conversion, voltage is promoted to voltage conditions about audio-frequency power amplifier system output 20W, and take the mode of capacitance energy storage, when the peak value of music signal, provide transient energy, and when the low valley of music signal USB by DC-DC to its makeup energy.
Such scheme has solved the problem of the larger transient peak power of USB mouth LVPS output, but because storage capacitor can not unrestrictedly strengthen, therefore, continue high-power being restricted of output, during especially for the large music signal of intensity, the energy that is stored in the electric capacity will be exhausted by load very soon, but the energy in the storage capacitor also has little time to replenish at this moment, therefore overall output energy still by 2.5 watts of these input power restricts in the very short time, so this scheme output transient power is about 20 watts of magnitudes.
Summary of the invention
The purpose of this utility model is to provide a kind of audio-frequency amplifier system based on computer USB Power supply and the integration of USB sound card, by increasing battery energy storage, allow significantly prolong with the continuous wave output time under the power rank, and guarantee significantly to promote power output under the condition of original transient state output time.
The purpose of this utility model is achieved through the following technical solutions.
A kind of audio-frequency amplifier system based on computer USB Power supply and the integration of USB sound card; comprise: detect protective circuit; the DC/DC power supply; audio amplifier circuit; battery charging and discharging and overvoltage crowbar; the transient state storage capacitor; USB sound card digital audio input circuit; preamplifying circuit; the USB power supply is inputted after testing protective circuit and is linked to each other with DC/DC power supply and battery charging and discharging and overvoltage crowbar respectively; USB sound card digital audio input circuit outputs to volume control through preamplifying circuit; by volume control audio signal is input to audio amplifier circuit; battery charging and discharging and overvoltage crowbar output through the DC/DC Power supply to audio amplifier circuit; simultaneously; battery charging and discharging and overvoltage crowbar connect battery pack, so that the battery charging energy-storing to be provided.
Preferably; described battery charging and discharging and overvoltage; low-voltage protection circuit; by integrated chip (U7); charge controlling chip (U5); control of discharge chip (U6); battery pack; relay (J2); capacitor C 70 and resistance R 48 form; electrical equipment (J2) coil power supply is succeeded in the output of USB power supply; relay (J2) control end is through the 2nd pin of battery winding charge controlling chip (U5); the 5th pin of charge controlling chip (U5) links to each other with the 1st pin of integrated chip (U7); control of discharge chip (U6) the 4th pin links to each other with the 3rd pin of integrated chip (U7); shunt capacitance C70 and link to each other with the 2nd pin of charge controlling chip (U5) between the 6th pin of integrated chip (U7) and the 5th pin; the 2nd pin of integrated chip (U7) links to each other with control of discharge chip (U6) the 6th pin through resistance R 48; the 5th pin of integrated chip (U7) connects power output end (VCC) through resistance R 49; when USB connects with the mains; voltage is powered to relay; relay (J2) adhesive; cell voltage is powered to audio amplifier circuit with the voltage of constant-current source; guaranteeing has enough electric currents and voltage high-power and large dynamically the time.
Preferably, described USB sound card digital audio input circuit comprises integrated circuit (U2) crystal oscillator (Y1), described preamplifying circuit comprises the first amplifier (U3A), the second amplifier (U3B), capacitor C 51 ~ C54, when USB inserts computer interfaceJi Suanjijiekou, peripheral cell crystal oscillator (Y1) starting of oscillation of integrated circuit (U2), 15 pin of integrated circuit (U2) and 16 pin output simulated audio signals (L/R) minute are clipped to capacitor C 51, C52 is by C51 C52 coupling capacitance to the first amplifier (U3A), after amplifying, the prime of the second amplifier (U3B) is capacitively coupled to volume control by C53 C54.
Preferably, described audio amplifier circuit comprises integrated power amplification chip (U4), capacitor C 71, C35, volume control end is passed through C35, C71 coupling capacitance to integrated power amplification chip (U4) the 6th, the 18th pin with analog signal (L/R), and output signal is play to loud speaker after integrated power amplification chip (U4) is processed.
Preferably; described detection protective circuit and DC/DC power supply comprise: integrated chip (U1); resistance R 4; R5; metal-oxide-semiconductor Q2; Q3; electronic transformer (T1); diode D1; D4; D5; the input of computer USB power supply is through resettable fuse (F1); provide operating voltage through diode D1 to integrated chip (U1); simultaneously; process is by triode Q1; R2; the constant-current source that R3 forms offers the centre cap driving voltage of electronic transformer (T1); electronic transformer work this moment; through D4; D5 Quick-return diode rectification goes out direct voltage and powers to integrated power amplification chip (U4); simultaneously between dc voltage output end (VDD) and electronic transformer (T1) secondary centre cap, be parallel with transient state storage capacitor C3, and secondary centre cap ground connection.
Preferably, described triode Q1 is transistor.
Preferably, described integrated chip (U1) is built-in oscillator+4.5V to+15V push-pull type current feed Topology Driven device.
Preferably, described integrated chip (U1) adopts thermal-enhanced 8 pin μ MAX encapsulation, is operated in-40 ° of C to+125 ° of C temperature ranges.
The utility model compared with prior art, beneficial effect is: the audio-frequency amplifier system based on computer USB Power supply and the integration of USB sound card that the utility model provides, existing energy-storage units is made into the mode of battery and electric capacity combination by single electric capacity, by increasing battery energy storage, allow significantly prolong with the continuous wave output time under the power rank, and guarantee significantly to promote power output under the condition of original transient state output time.
Description of drawings
Fig. 1 is the graph of a relation of power, power supply, music peak power and average musical power.
Fig. 2 is the utility model audio-frequency amplifier system theory diagram.
Fig. 3 is USB sound card digital audio input circuit schematic diagram.
Fig. 4 is the preamplifying circuit schematic diagram.
Fig. 5 is the audio amplifier circuit schematic diagram.
Fig. 6 is that the power supply input detects protective circuit and DC/DC power principle figure.
Fig. 7 is battery charging and discharging and overvoltage, low-voltage protection circuit schematic diagram.
Embodiment
In order to make the purpose of this utility model, technical scheme and advantage clearer, below in conjunction with drawings and Examples, the utility model is further elaborated.Should be appreciated that specific embodiment described herein only in order to explaining the utility model, and be not used in restriction the utility model.
See also shown in Figure 2; the audio-frequency amplifier system based on computer USB Power supply and the integration of USB sound card that the utility model provides; comprise: detect protective circuit 1; DC/DC power supply 2; audio amplifier circuit 3; battery charging and discharging and overvoltage crowbar 4; transient state storage capacitor 5; USB sound card digital audio input circuit 6; preamplifying circuit 7; the USB power supply is inputted after testing protective circuit 1 and is linked to each other with DC/DC power supply 2 and battery charging and discharging and overvoltage crowbar 4 respectively; 3 power supplies of DC/DC power supply 2 output termination audio amplifier circuits; USB sound card digital audio input circuit 6 outputs to volume control through preamplifying circuit 7; by volume control audio signal is input to audio amplifier circuit 6; battery charging and discharging and overvoltage crowbar 4 outputs are powered to audio amplifier circuit 3 through DC/DC power supply 2; simultaneously; battery charging and discharging and overvoltage crowbar 4 connect battery pack, so that the battery charging energy-storing to be provided.
Because the output of the transient state of music signal itself and average output power ratio are at 8:1 even lower, it is free time that the while music signal has a lot of times, therefore USB interface energy most of the time of providing is the battery charging, to satisfy the high dynamic need of high-power long period, when exporting, the provisional transient state of needs provides energy by electric capacity, and auxiliary to provide output larger energy by battery during continuous transient state peak power output.
In the utility model, the USB sound card is the audio data stream that directly reads on the computer, thereby reduces the loss of audio data stream, adopts simultaneously the USB Power supply, and directly the omitting external power supply reduces cost; And adopt the USB sound card also to save being connected of holding wire and computer, overcome the power of traditional multi-media sound system low with the factors such as tonequality is bad.
See also shown in Fig. 3,4, USB sound card digital audio input circuit 6 is comprised of the U2 integrated circuit, when USB inserts computer interfaceJi Suanjijiekou, the shielding computer sound card, peripheral cell crystal oscillator (Y1) starting of oscillation of U2, U2 has the maximum sample rate of 16 precision and 48KHz, and to have ADC and the dynamic range that dynamic range is 89dB (representative value) be the DAC of 93dB (representative value).U2 is built-in to prevent from illegally copying the defencive function of (SCMS), and with the 12MHz sheet on the clock generator full duplex compatible.Minute be clipped to capacitor C 51, C52 from 15 pin of U2 and 16 pin output simulated audio signals (L/R), after the prime of U3A, U3B is amplified, be capacitively coupled to volume control by C53 C54 by C51 C52 coupling capacitance.
See also shown in Figure 5, volume control end with analog signal (L/R) by C35, C71 coupling capacitance to audio amplifier circuit U4 the 6th, the 18th pin, output signal is play to loud speaker after U4 processes.U4 is integrated power amplification chip IC, and power amplifier sound is better, and high frequency is penetrating, and parsing power improves many, and low frequency more has dynamics.Complete noise made in coughing or vomiting clatter sound suppresses circuit can effectively be reduced and turn-off and pick-up noise and output noise when quiet.The audible noise that excellent clamper recovery characteristics has produced when having eliminated the pseudo-overload of D class A amplifier A also has the reliable work that heat protection and short-circuit protection have guaranteed chip.
See also shown in Figure 6,5V/500mA is through resettable fuse F1 for the input of computer USB power supply, provide operating voltage through diode D1 to the U1 chip, simultaneously, offer the centre cap driving voltage of electronic transformer T1 through the constant-current source that is formed by Q1, R2, R3.Electronic transformer work this moment goes out direct voltage and amplifies IC(U4 to audio frequency through D4, D5 Quick-return diode rectification) power supply.Simultaneously between dc voltage output end VDD and electronic transformer T1 secondary centre cap, be parallel with transient state storage capacitor C3, and secondary centre cap ground connection.
Above-mentioned U1 is a built-in oscillator+4.5V to+15V push-pull type current feed Topology Driven device subsystem, is applicable to the telco module power supply.This device can drive two MOSFET that link to each other with the former limit of centre-tapped transformer, and negative voltage or the positive voltage of isolation is provided for secondary.The accurate oscillator of this device inside integrated programmable has synchronised clock output, can be used for synchronous outside pwm modulator.By single non-essential resistance programming the internal oscillator frequency is set, scope is 50kHz to 1.5MHz.It is two mosfet drivers of 50% for ± 3A and duty ratio that U1 inside is integrated with peak drive current.This mosfet driver produces complementary signal and drives and take ground as the outside n channel mosfet of reference.The ratio of U1 clock output frequency and mosfet driver frequency has 1 times, 2 times and 4 times three kinds.U1 adopts thermal-enhanced 8 pin μ MAX encapsulation, is operated in-40 ° of C to+125 ° of C temperature ranges.U1 key characteristic: 1. current feed, push-pull driver subsystem.2. internal oscillator able to programme, accurate.3.+4.5V is to+15V single supply.4. two-way ± 3A grid driver output.5. under the 250kHz frequency, and during without capacitive load, operating current is 1mA.6. the synchronised clock frequency is selected.7. thermal-enhanced 8 pin μ MAXL encapsulation.8. operating temperature range is that-40 ° of C are to+125 ° of C.
Above-mentioned constant-current source is a kind of circuit that constant current can be provided to load, it both can be for various amplifying circuits provide bias current to stablize its quiescent point, again can be as its active load, so that multiplication factor to be provided, and at differential amplifier circuit, pulse-generating circuit is widely used.Yet various constant-current circuits are contrasted, analyze separately application characteristic, can be divided three classes, 1. transistor constant current source.2. FET-constant current source.3. integrated operational amplifier constant current source, the utility model has adopted the first, i.e. transistor constant current source.
Above-mentioned resettable fuse F1 is the power supply system that the front occurs unusually damaging because of the back circuit in order to protect.
See also shown in Figure 7; the utility model battery charging and discharging and overvoltage; low-voltage protection circuit; by integrated chip (U7); charge controlling chip (U5); control of discharge chip (U6); battery pack; relay (J2); capacitor C 70 and resistance R 48 form; electrical equipment (J2) coil power supply is succeeded in the output of USB power supply; relay (J2) control end is through the 2nd pin of battery winding charge controlling chip (U5); the 5th pin of charge controlling chip (U5) links to each other with the 1st pin of integrated chip (U7); control of discharge chip (U6) the 4th pin links to each other with the 3rd pin of integrated chip (U7); shunt capacitance C70 and link to each other with the 2nd pin of charge controlling chip (U5) between the 6th pin of integrated chip (U7) and the 5th pin; the 2nd pin of integrated chip (U7) links to each other with control of discharge chip (U6) the 6th pin through resistance R 48; the 5th pin of integrated chip (U7) connects power output end (VCC) through resistance R 49; when USB connects with the mains; voltage is powered to relay; relay (J2) adhesive; cell voltage is powered to audio amplifier circuit with the voltage of constant-current source; guaranteeing has enough electric currents and voltage high-power and large dynamically the time.
U7 is overcharging of a high-precision single-unit chargeable lithium cell and over circuit, and it integrates the performances such as high accuracy overvoltage charge protection, overcurrent charge protection, overvoltage discharge prevention, overcurrent discharge prevention.Under the normal condition; the 5th pin vdd terminal voltage of U7 is between overvoltage charge protection threshold value (VOC) and overvoltage discharge prevention threshold value (VOD); and its 6th pin VSS test side voltage is between overcurrent charge protection threshold value (COUT) and overcurrent discharge prevention threshold value (VOUT); this moment, COUT end and the DOUT end of U7 were all exported high level, made respectively external charge control U5 and control of discharge U6 work conducting.At this moment, both can use charger that battery is charged, also can make battery discharge by load.U7 overcharges/discharge prevention by detecting VDD or VSS terminal voltage.COUT/DOUT becomes low level by high level when the charge/discharge protective condition occurs, and makes that Q1/Q2 becomes cut-off by conducting among Fig. 6, thereby the charge/discharge process stops.U7 has corresponding recovery condition to every kind of guard mode, and after the recovery condition satisfied, COUT/DOUT became high level by low level, makes U5/U6 become conducting by cut-off, thus the normal condition of entering.U7 is provided with certain time of delay to every kind of protection/recovery condition, only after protection/recovery condition lasts till the corresponding time, just protects accordingly/recover.If protection/recovery condition was eliminated in the past in corresponding time of delay, then do not enter and protect/return to form.For music, when music stops, power amplifier is hardly during consumed energy, charging control section is divided and most extraneous input energy will be charged to rechargeable battery with the fastest charging modes, when musical power output is arranged, but power is also less than the energy that obtains from the external world, charging control circuit is stored in remaining energy in the rechargeable battery equally, when there being transient peak power to arrive, and in the 100mS that the duration of transient peak power can bear in the transient energy storage unit, the battery pack of this moment can not participate in energy supplement work equally, under above three kinds of conditions, rechargeable battery always in stored energy (charging), is just can stop until the energy of rechargeable battery storage reaches capacity limit by charging control circuit; Energy discharge (discharge) also is intelligent, starts threshold level (V by a discharge is set
STATE) and two discharges close threshold values (V
STOP_L, V
STOP_H), in case that is to say when the supply power voltage of power amplifier reduces because of the increase of the power of output, battery discharge is not just to participate in immediately replenishing of energy, its intervention is to have dropped into V at discharge management unit inspection to amplifier power supply
STATEThe time, battery pack is just replenished the energy of power amplifier consumption, and the threshold values that stops to discharge then depends on V
STOP_LAnd V
STOP_H, V wherein
STOP_HThe threshold level behind the amplifier power supply voltage recovery, V
STOP_LIt then is the lowest limit threshold values of battery pack continuous discharge.This circuit has also added the hardware protection battery; even disconnect the USB power supply; the electric weight of battery also is to be kept at full state, and when USB connected with the mains ,+5V voltage was powered to relay; the J2 adhesive; cell voltage is given the power supply of electronic transformer T1 centre cap with the voltage of constant-current source, and guaranteeing has enough electric currents and voltage to guarantee the steady operation of T1 high-power and large when dynamic; the inadequate sound of electric current and the phenomenons such as pause have been guaranteed when large dynamic output.When extracting USB, relay J 2 trippings have guaranteed that battery is in full state in the situation of outage, and can automatic discharging.So also help to promote performance and the life-span of battery charging and discharging in the native system, the transient energy storage element also is the power filtering capacitor of power conversion output and power amplifier unit usually, improves power supply ripple.
The above only is preferred embodiment of the present utility model; not in order to limit the utility model; all any modifications of within spirit of the present utility model and principle, doing, be equal to and replace and improvement etc., all should be included within the protection range of the present utility model.
Claims (8)
1. audio-frequency amplifier system of integrating based on computer USB Power supply and USB sound card; it is characterized in that; comprise: detect protective circuit; the DC/DC power supply; audio amplifier circuit; battery charging and discharging and overvoltage crowbar; the transient state storage capacitor; USB sound card digital audio input circuit; preamplifying circuit; the USB power supply is inputted after testing protective circuit and is linked to each other with DC/DC power supply and battery charging and discharging and overvoltage crowbar respectively; USB sound card digital audio input circuit outputs to volume control through preamplifying circuit; by volume control audio signal is input to audio amplifier circuit; battery charging and discharging and overvoltage crowbar output through the DC/DC Power supply to audio amplifier circuit; simultaneously; battery charging and discharging and overvoltage crowbar connect battery pack, so that the battery charging energy-storing to be provided.
2. the audio-frequency amplifier system of integrating based on computer USB Power supply and USB sound card as claimed in claim 1; it is characterized in that; described battery charging and discharging and overvoltage; low-voltage protection circuit; by integrated chip (U7); charge controlling chip (U5); control of discharge chip (U6); battery pack; relay (J2); capacitor C 70 and resistance R 48 form; electrical equipment (J2) coil power supply is succeeded in the output of USB power supply; relay (J2) control end is through the 2nd pin of battery winding charge controlling chip (U5); the 5th pin of charge controlling chip (U5) links to each other with the 1st pin of integrated chip (U7); control of discharge chip (U6) the 4th pin links to each other with the 3rd pin of integrated chip (U7); shunt capacitance C70 and link to each other with the 2nd pin of charge controlling chip (U5) between the 6th pin of integrated chip (U7) and the 5th pin; the 2nd pin of integrated chip (U7) links to each other with control of discharge chip (U6) the 6th pin through resistance R 48; the 5th pin of integrated chip (U7) connects power output end (VCC) through resistance R 49; when USB connects with the mains; voltage is powered to relay; relay (J2) adhesive; cell voltage is powered to audio amplifier circuit with the voltage of constant-current source; guaranteeing has enough electric currents and voltage high-power and large dynamically the time.
3. the audio-frequency amplifier system of integrating based on computer USB Power supply and USB sound card as claimed in claim 2, it is characterized in that, described USB sound card digital audio input circuit comprises integrated circuit (U2) crystal oscillator (Y1), described preamplifying circuit comprises the first amplifier (U3A), the second amplifier (U3B), capacitor C 51 ~ C54, when USB inserts computer interfaceJi Suanjijiekou, peripheral cell crystal oscillator (Y1) starting of oscillation of integrated circuit (U2), 15 pin of integrated circuit (U2) and 16 pin output simulated audio signals (L/R) minute are clipped to capacitor C 51, C52 passes through C51, C52 coupling capacitance to the first amplifier (U3A), the prime of the second amplifier (U3B) is amplified rear by C53, C54 is capacitively coupled to volume control.
4. the audio-frequency amplifier system of integrating based on computer USB Power supply and USB sound card as claimed in claim 3, it is characterized in that, described audio amplifier circuit comprises integrated power amplification chip (U4), capacitor C 71, C35, volume control end is passed through C35, C71 coupling capacitance to integrated power amplification chip (U4) the 6th, the 18th pin with analog signal (L/R), and output signal is play to loud speaker after integrated power amplification chip (U4) is processed.
5. the audio-frequency amplifier system of integrating based on computer USB Power supply and USB sound card as claimed in claim 4; it is characterized in that; described detection protective circuit and DC/DC power supply comprise: integrated chip (U1); resistance R 4; R5; metal-oxide-semiconductor Q2; Q3; electronic transformer (T1); diode D1; D4; D5; the input of computer USB power supply is through resettable fuse (F1); provide operating voltage through diode D1 to integrated chip (U1); simultaneously; process is by triode Q1; R2; the constant-current source that R3 forms offers the centre cap driving voltage of electronic transformer (T1); electronic transformer work this moment; through D4; D5 Quick-return diode rectification goes out direct voltage and powers to integrated power amplification chip (U4); simultaneously between dc voltage output end (VDD) and electronic transformer (T1) secondary centre cap, be parallel with transient state storage capacitor C3, and secondary centre cap ground connection.
6. the audio-frequency amplifier system based on computer USB Power supply and the integration of USB sound card as claimed in claim 5 is characterized in that described triode Q1 is transistor.
7. the audio-frequency amplifier system of integrating based on computer USB Power supply and USB sound card as claimed in claim 5 is characterized in that, described integrated chip (U1) be built-in oscillator+4.5V extremely+15V push-pull type current feed Topology Driven device.
8. the audio-frequency amplifier system based on computer USB Power supply and the integration of USB sound card as claimed in claim 5 is characterized in that, described integrated chip (U1) adopts thermal-enhanced 8 pin μ MAX encapsulation, is operated in-40 ° of C to+125 ° of C temperature ranges.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220263356 CN202696541U (en) | 2012-06-06 | 2012-06-06 | Audio frequency amplifier system based on electricity supply of computer USB (universal serial bus) power supply and integration of USB sound card |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220263356 CN202696541U (en) | 2012-06-06 | 2012-06-06 | Audio frequency amplifier system based on electricity supply of computer USB (universal serial bus) power supply and integration of USB sound card |
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| CN202696541U true CN202696541U (en) | 2013-01-23 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN 201220263356 Expired - Lifetime CN202696541U (en) | 2012-06-06 | 2012-06-06 | Audio frequency amplifier system based on electricity supply of computer USB (universal serial bus) power supply and integration of USB sound card |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102694506A (en) * | 2012-06-06 | 2012-09-26 | 国光电器股份有限公司 | Audio-frequency amplifier system powered based on power supply of computer USB (Universal Serial Bus) power source and integration of USB audio card |
| CN110445212A (en) * | 2019-08-12 | 2019-11-12 | 杨成波 | A method of control discharge current is exported based on cell voltage clipping regulation power |
-
2012
- 2012-06-06 CN CN 201220263356 patent/CN202696541U/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102694506A (en) * | 2012-06-06 | 2012-09-26 | 国光电器股份有限公司 | Audio-frequency amplifier system powered based on power supply of computer USB (Universal Serial Bus) power source and integration of USB audio card |
| CN110445212A (en) * | 2019-08-12 | 2019-11-12 | 杨成波 | A method of control discharge current is exported based on cell voltage clipping regulation power |
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