CN208174646U - A kind of automatic level control circuit - Google Patents
A kind of automatic level control circuit Download PDFInfo
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- CN208174646U CN208174646U CN201821551096.0U CN201821551096U CN208174646U CN 208174646 U CN208174646 U CN 208174646U CN 201821551096 U CN201821551096 U CN 201821551096U CN 208174646 U CN208174646 U CN 208174646U
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- circuit
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- effect tube
- capacitor
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Abstract
The utility model discloses a kind of automatic level control circuits, are connected between the input terminal of signal source and output end, including amplifying circuit, rectification circuit, bleeder circuit one, attenuator；Amplifying circuit is connected between signal source input terminal and output end, and rectification circuit, bleeder circuit, attenuator are connected in parallel on the both ends of amplifying circuit after being sequentially connected in series；The output end of the input terminal connection amplifying circuit of rectification circuit；Attenuator is field-effect tube attenuator；The bleeder circuit one includes the first concatenated first divider and the second divider, and the control terminal of the field-effect tube attenuator is connected between the first divider and the second divider.The automatic level control circuit of the utility model, it is not easy to which the problem of causing output signal to be distorted realizes the level control of amplifier output low distortion.In addition bleeder circuit one is added in automatic level control circuit, with starting to control a little for the first divider and the adjustable field-effect tube attenuator of the second divider.
Description
Technical field
The utility model relates to signal source domains, more particularly to a kind of automatic level control circuit.
Background technique
In signal source domain, the amplitude of output signal is generally required to meet certain accuracy.Such as it is logical in electronics frequency modulation
Believe in equipment, it usually needs the saturation distortion of control voice signal level and signal is put with limiting FM frequency modulation or audio
The maximum power of big device, this just needs automatic level control circuit（ALC）.
The alc circuit of the prior art, as shown in Fig. 1.Input signal obtains direct-current control voltage by rectifier, this electricity
Pressure is added on attenuator, the input signal amplitude of amplifier is controlled, to reach auto level control purpose.Common automatic electric-level
Control circuit, attenuator are made of triode, and control voltage is added on transistor base and provides base bias current, to control
Triode ON characteristic processed, realizes the adjustable attenuation of input signal amplitude.Since triode needs base current to bias, thus this
Circuit easily causes the distortion of output signal, so that the dynamic range of automatic level control circuit is not big enough.
Utility model content
In order to solve the above problems existing in the present technology, the utility model discloses a kind of automatic level control circuit.
A kind of automatic level control circuit, is connected between the input terminal of signal source and output end, including amplifying circuit, whole
Current circuit, bleeder circuit one, attenuator；The amplifying circuit is connected between signal source input terminal and output end, the rectification
Circuit, bleeder circuit, attenuator are connected in parallel on the both ends of amplifying circuit after being sequentially connected in series；
The output end of the input terminal connection amplifying circuit of the rectification circuit；
The attenuator is field-effect tube attenuator；
The bleeder circuit one includes the first concatenated first divider and the second divider, the field-effect tube attenuator
Control terminal be connected between the first divider and the second divider.
Signal source input end signal obtains DC voltage after the amplification of amplifying circuit, by rectification circuit；It is described straight
Galvanic electricity pressure is added on attenuator after the partial pressure of bleeder circuit one, controls the input terminal input signal amplitude of amplifying circuit.This is practical
It is novel by the way that the triode attenuator in existing automatic level control circuit is changed to field-effect tube attenuator, solve because
Triode needs base current to bias, and the problem of be easy to cause output signal to be distorted.Realize the electricity of amplifier output low distortion
Flat control.In addition bleeder circuit one is added in automatic level control circuit, can be adjusted with the first divider and the second divider
Section field-effect tube attenuator starts to control a little, and when so that output must reach certain amplitude, automatic level control circuit ACL just starts
It works.
Preferably, the rectification circuit is voltage doubling rectifing circuit.
As a preferred scheme of voltage doubling rectifing circuit, voltage doubling rectifing circuit is two voltage doubling rectifying circuit.Two multiplication of voltages
Rectification circuit includes the second capacitor C2, third capacitor C3, diode rectifier D1；The first end connection amplification electricity of third capacitor C3
The output end on road, second end connect the input terminal of diode rectifier D1；The positive pressure output end connection the of diode rectifier D1
The negative pressure output end of two capacitor C2, diode rectifier D1 are grounded；The input terminal of bleeder circuit one is connected to diode rectifier
Between the positive pressure output end of D1 and the second capacitor C2；Second capacitor C2 ground connection.Second capacitor C2, third capacitor C3 are voltage multiplying rectifier
Capacitor；Third capacitor has both coupled capacitor function.
As a preferred option, the voltage doubling rectifing circuit is two voltage doubling rectifying circuit, the two voltage doubling rectifying circuit packet
Include the second capacitor, third capacitor, first diode, the second diode；The output end of the third capacitance connection amplifying circuit, institute
It states in parallel with first diode both ends again after the second diode is connected with the second capacitor；The first diode forward direction connection, institute
State the second diode Opposite direction connection；The input terminal of the bleeder circuit one is connected to the cathode of first diode, second electricity
Hold and the second diode indirectly.
The first end of the field-effect tube attenuator is connect with signal source input terminal, and the second of the field-effect tube attenuator
End ground connection.
Preferably, the field-effect tube attenuator is the road depletion type N ditch field-effect tube, the control of the field-effect tube attenuator
End processed is grid, and the first end of field-effect tube attenuator is source electrode, and second end is drain electrode.
As a preferred option, first divider is second resistance, and second divider is 3rd resistor；It is described
Second resistance is connected to the output end of rectification circuit, the 3rd resistor ground connection.
Preferably, bleeder circuit two is also in series between the field-effect tube attenuator and signal source input terminal；Described point
The first end connection field-effect tube attenuator of volt circuit two, second end are connected between amplifying circuit and signal source input terminal.
Preferably, the bleeder circuit two is first resistor.First resistor can conveniently adjust the dynamic range of circuit, together
When guarantee scene effect pipe attenuator when fully on, signal be unlikely to decaying it is too big.
The amplifying circuit is amplifier.
Beneficial effect：The utility model is by being changed to field for the triode attenuator in existing automatic level control circuit
Effect pipe attenuator solves because triode needs base current to bias, and the problem of be easy to cause output signal to be distorted.It is real
The level control of existing amplifier output low distortion.In addition bleeder circuit one is added in automatic level control circuit, with first point
Depressor and the adjustable field-effect tube attenuator of the second divider start to control a little, when so that output must reach certain amplitude, from
Dynamic level control circuit ACL is just started working.Further, circuit can obtain biggish dynamic range.
Detailed description of the invention
Fig. 1 is a kind of circuit diagram of automatic level control circuit of this prior art；
Fig. 2 is the waveform signal of the input signal and output signal of a kind of automatic level control circuit of this prior art
Figure；
Fig. 3 is a kind of module diagram of automatic level control circuit described in the utility model embodiment；
Fig. 4 is a kind of circuit diagram of automatic level control circuit described in the utility model embodiment；
Fig. 5 is a kind of waveform diagram of automatic level control circuit described in the utility model embodiment.
Specific embodiment
The following will be combined with the drawings in the embodiments of the present invention, carries out the technical scheme in the embodiment of the utility model
Clearly and completely describe, it is clear that the described embodiments are only a part of the embodiments of the utility model, rather than whole
Embodiment.Based on the embodiments of the present invention, those of ordinary skill in the art are without making creative work
Every other embodiment obtained, fall within the protection scope of the utility model.
Embodiment one
A kind of automatic level control circuit provided by the embodiment of the utility model is discussed in detail, referring to shown in Fig. 3, Fig. 4.
A kind of automatic level control circuit, is connected between the input terminal of signal source and output end, including amplifying circuit 11, rectification circuit
13, bleeder circuit 1, attenuator 12.Amplifying circuit 11 is connected between signal source input terminal and output end.Rectification circuit 13,
Bleeder circuit 14, attenuator 12 are connected in parallel on the both ends of amplifying circuit 11 after being sequentially connected in series.The input terminal connection of rectification circuit 13 is put
The output end of big circuit 11.Attenuator 12 is field-effect tube attenuator Q1；Bleeder circuit 1 includes first concatenated first point
The control terminal of depressor and the second divider, field-effect tube attenuator Q1 is connected between the first divider and the second divider.
Signal source input end signal obtains DC voltage after the amplification of amplifying circuit 11, by rectification circuit 13；Directly
Galvanic electricity pressure is added on attenuator Q1 after the partial pressure of bleeder circuit 1, can control the input terminal input signal width of amplifying circuit 11
Degree.
The utility model is declined by the way that the triode attenuator in existing automatic level control circuit is changed to field-effect tube
The problem of subtracting device, solving because triode needs base current to bias, and output signal is be easy to cause to be distorted, realizes amplifier
Export the level control of low distortion.In addition bleeder circuit one is added in automatic level control circuit, with the first divider and the
The adjustable field-effect tube attenuator of two divider starts to control a little, when so that output must reach certain amplitude, automatic electric-level control
Circuit ACL processed is just started working.
The first end of field-effect tube attenuator Q1 is connect with signal source input terminal, the second end of the field-effect tube attenuator
Ground connection.
Preferable scheme is that field-effect tube attenuator Q1 is the road depletion type N ditch field-effect tube, field-effect tube attenuator Q1's
Control terminal is grid, and the first end of field-effect tube attenuator is source electrode, and second end is drain electrode.The source electrode of field-effect tube attenuator Q1
With in drain electrode one of ground connection, another connect with signal source input terminal.
As a preferred option, rectification circuit 13 is voltage doubling rectifing circuit.It is compared to traditional diode rectifier, times
The available enough direct-current control voltages of voltage rectifier；There is cost advantage again compared to bridge rectifier.Voltage multiplying rectifier electricity
Road can be two voltage doubling rectifying circuit or voltage tripler rectifier circuit or other its voltage doubling rectifing circuits.
As shown in figure 4, a preferred scheme as voltage doubling rectifing circuit, voltage doubling rectifing circuit is voltage-doubler rectification electricity
Road.Two voltage doubling rectifying circuit includes the second capacitor C2, third capacitor C3, diode rectifier D1；The first end of third capacitor C3
The output end of amplifying circuit is connected, second end connects the input terminal of diode rectifier D1；The positive pressure of diode rectifier D1 is defeated
Outlet connects the second capacitor C2, the negative pressure output end ground connection of diode rectifier D1；The input terminal of bleeder circuit one is connected to two
Between the positive pressure output end of pole pipe rectifier D1 and the second capacitor C2；Second capacitor C2 ground connection.Second capacitor C2, third capacitor C3
For voltage multiplying rectifier capacitor；Third capacitor has both coupled capacitor function.
It as another preferred scheme of voltage doubling rectifing circuit, is not shown in the figure, voltage doubling rectifing circuit is two times of repoussages
Current circuit.Two voltage doubling rectifying circuit includes the second capacitor C2, third capacitor C3, first diode, the second diode；Third capacitor
The output end of C3 connection amplifying circuit, the second diode are in parallel with first diode both ends again after connecting with the second capacitor C2；Its
Middle first diode forward direction connection, the second diode Opposite direction connection；The input terminal of bleeder circuit 1 is connected to first diode
Cathode, the second capacitor C2 and the second diode indirectly.Second capacitor C2, third capacitor C3 are voltage multiplying rectifier capacitor；The
Three capacitors have both coupled capacitor function.Wherein first diode and the second diode can be the diode rectifier of encapsulation, the
The cathode of one diode is the positive pressure output end of diode rectifier, the just extremely negative pressure of diode rectifier of the second diode
Output end.
As shown in figure 4, as a preferred option, the first divider is second resistance R2, the second divider is 3rd resistor
R3；Second resistance R2 is connected to the output end of rectification circuit 13,3rd resistor R3 ground connection.
Preferably, bleeder circuit 2 15 is also in series between field-effect tube attenuator Q1 and signal source input terminal.Partial pressure electricity
The first end connection field-effect tube attenuator Q1 on road 2 15, second end are connected between amplifying circuit 11 and signal source input terminal.
The singal source resistance Rs of signal source input terminal is by the electricity of conducting resistance and bleeder circuit 2 15 with field-effect tube attenuator Q1
Resistance forms bleeder circuit, so that the signal amplitude of input amplifying circuit 11 is controlled, circuit can have biggish dynamic
State range.
Preferably, bleeder circuit two is first resistor R1.First resistor R1 can conveniently adjust the dynamic range of circuit, together
When guarantee scene effect pipe attenuator Q1 when fully on, signal be unlikely to decaying it is too big.
Preferably, field-effect tube attenuator Q1 is the road depletion type N ditch field-effect tube, the source electrode and letter of field-effect tube attenuator
The connection of number source input terminal, grounded drain.
More specifically, amplifying circuit 11 is amplifier.
Fig. 5 is a kind of waveform diagram of automatic level control circuit described in the utility model embodiment.
Beneficial effect：The utility model is by being changed to field for the triode attenuator in existing automatic level control circuit
Effect pipe attenuator solves because triode needs base current to bias, and the problem of be easy to cause output signal to be distorted.It is real
The level control of existing amplifier output low distortion.In addition bleeder circuit one is added in automatic level control circuit, with first point
Depressor and the adjustable field-effect tube attenuator of the second divider start to control a little, when so that output must reach certain amplitude, from
Dynamic level control circuit ACL is just started working.Further, circuit can obtain biggish dynamic range.
It should be understood that for those of ordinary skills, it can be modified or changed according to the above description,
All these improvement or transformation all should belong within the protection scope of the appended claims for the utility model.
Claims (10)
1. a kind of automatic level control circuit, is connected between the input terminal of signal source and output end, which is characterized in that automatic electric
Level control circuit includes amplifying circuit, rectification circuit, bleeder circuit one, attenuator；It is defeated that the amplifying circuit is connected to signal source
Enter between end and output end, the rectification circuit, bleeder circuit, attenuator are connected in parallel on the both ends of amplifying circuit after being sequentially connected in series；
The output end of the input terminal connection amplifying circuit of the rectification circuit；The attenuator is field-effect tube attenuator；It is described
Bleeder circuit one includes the first concatenated first divider and the second divider, and the control terminal of the field-effect tube attenuator connects
Between the first divider and the second divider.
2. control circuit according to claim 1, which is characterized in that the rectification circuit is voltage doubling rectifing circuit.
3. control circuit according to claim 2, which is characterized in that the voltage doubling rectifing circuit is voltage-doubler rectification electricity
Road, the two voltage doubling rectifying circuit include the second capacitor, third capacitor, first diode, the second diode；The third capacitor
The output end of amplifying circuit is connected, second diode is in parallel with first diode both ends again after connecting with the second capacitor；Institute
State the connection of first diode forward direction, the second diode Opposite direction connection；The input terminal of the bleeder circuit one is connected to first
The cathode of diode, second capacitor and the second diode indirectly.
4. control circuit according to claim 2, which is characterized in that the voltage doubling rectifing circuit is voltage-doubler rectification electricity
Road；Two voltage doubling rectifying circuit includes the second capacitor, third capacitor, diode rectifier；The first end of the third capacitor connects
The output end of amplifying circuit, second end connect the input terminal of diode rectifier；The positive pressure output end of the diode rectifier
Connect the second capacitor, the negative pressure output end ground connection of diode rectifier；The input terminal of the bleeder circuit one is connected to diode
Between the positive pressure output end and the second capacitor of rectifier；Second capacity earth.
5. control circuit according to claim 1, which is characterized in that the first end and signal of the field-effect tube attenuator
The connection of source input terminal, the second end ground connection of the field-effect tube attenuator.
6. control circuit according to claim 5, which is characterized in that the field-effect tube attenuator is the road depletion type N ditch
Field-effect tube, the control terminal of the field-effect tube attenuator are grid, and the first end of field-effect tube attenuator is source electrode, second end
For drain electrode.
7. control circuit according to claim 1, which is characterized in that first divider is second resistance, described the
Two divider are 3rd resistor；The second resistance is connected to the output end of rectification circuit, the 3rd resistor ground connection.
8. control circuit according to claim 1, which is characterized in that the field-effect tube attenuator and signal source input terminal
Between be also in series with bleeder circuit two；The first end of the bleeder circuit two connects field-effect tube attenuator, and second end is connected to
Between amplifying circuit and signal source input terminal.
9. control circuit according to claim 8, which is characterized in that the bleeder circuit two is first resistor.
10. control circuit according to claim 1, which is characterized in that the amplifying circuit is amplifier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821551096.0U CN208174646U (en) | 2018-09-21 | 2018-09-21 | A kind of automatic level control circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821551096.0U CN208174646U (en) | 2018-09-21 | 2018-09-21 | A kind of automatic level control circuit |
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| Publication Number | Publication Date |
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| CN208174646U true CN208174646U (en) | 2018-11-30 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201821551096.0U Active CN208174646U (en) | 2018-09-21 | 2018-09-21 | A kind of automatic level control circuit |
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| CN (1) | CN208174646U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2021213426A1 (en) * | 2020-04-21 | 2021-10-28 | 中兴通讯股份有限公司 | Automatic level control circuit, signal source, signal source output power control method, and storage medium |
-
2018
- 2018-09-21 CN CN201821551096.0U patent/CN208174646U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2021213426A1 (en) * | 2020-04-21 | 2021-10-28 | 中兴通讯股份有限公司 | Automatic level control circuit, signal source, signal source output power control method, and storage medium |
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| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20210219 Address after: 518000 Room 401, No.2 factory building, hainengda technology factory, No.3, Baolong 4th Road, Baolong community, Baolong street, Longgang District, Shenzhen City, Guangdong Province Patentee after: Shenzhen fuchuang superior technology Co., Ltd Address before: 518116 hainengda science and Technology Park, No.3, Baolong 4th Road, Baolong Industrial City, Baolong community, Longgang street, Longgang District, Shenzhen City, Guangdong Province Patentee before: Norsat International Inc. |
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| TR01 | Transfer of patent right |