CN217984850U - Filter circuit and device - Google Patents
Filter circuit and device Download PDFInfo
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- CN217984850U CN217984850U CN202221942965.9U CN202221942965U CN217984850U CN 217984850 U CN217984850 U CN 217984850U CN 202221942965 U CN202221942965 U CN 202221942965U CN 217984850 U CN217984850 U CN 217984850U
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Abstract
The utility model discloses a filter circuit and device relates to filtering technology field. The filter circuit comprises a signal filtering unit, an active filter unit, a clamping unit, a voltage input end and a voltage output end; the output voltage flows into the signal filtering unit through the voltage input end, and the signal filtering unit is used for filtering high-frequency small signal interference of the input voltage; the active filter unit is used for filtering ripples and instantaneous surges of input voltage to form direct-current output voltage; the clamping unit is used for clamping the direct current output voltage at a fixed value and outputting the direct current output voltage through the voltage output end; the signal filtering unit, the active filtering unit and the clamping unit are electrically connected in sequence and are arranged between the voltage input end and the voltage output end. According to the filter circuit of the embodiment of the utility model, the signal filtering unit can filter the interference of high-frequency small signals; the active filtering unit can filter out ripples and instantaneous surges; the clamping unit can clamp the DC output voltage at a fixed value.
Description
Technical Field
The utility model belongs to the technical field of the filtering technique and specifically relates to a filter circuit and device are related to.
Background
The existing high-voltage direct-current power supply circuit generally filters a power supply through a capacitor, an LC filter circuit consisting of a capacitor and an inductor, an RC filter circuit consisting of a capacitor and a resistor and other filter circuits. However, these filter circuits inevitably require the use of a high-voltage capacitor with a high withstand voltage, and the filter capacitors with high voltage and large capacity have high cost and large volume.
SUMMERY OF THE UTILITY MODEL
The utility model discloses aim at solving one of the technical problem that exists among the prior art at least. Therefore, the utility model provides a filter circuit and device can effective filtering ripple and restrain instantaneous surge.
On the one hand, according to the utility model discloses filter circuit, include: a voltage input terminal; the signal filtering unit is electrically connected with the voltage input end; the active filtering unit is electrically connected with the signal filtering unit; the clamping unit is electrically connected with the active filtering unit; and the voltage output end is electrically connected with the clamping unit.
According to the utility model discloses a some embodiments, signal filtering unit includes filter capacitor, filter capacitor's first end with voltage input end electricity is connected, filter capacitor's second end ground connection.
According to some embodiments of the invention, the active filtering unit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, a first switch and a second switch; the first end of the third resistor is electrically connected with the voltage input end, the second end of the third resistor is electrically connected with the first end of the fourth resistor, and the second end of the fourth resistor is grounded; the first capacitor is connected with the third resistor in parallel, the first end of the second capacitor is electrically connected with the voltage input end, and the second end of the second capacitor is electrically connected with the controlled end of the first switch; a first end of the second resistor is electrically connected with the voltage input end, a second end of the second resistor is electrically connected with a first end of the first switch, and a second end of the first switch is electrically connected with a connection point between a second end of the third resistor and a first end of the fourth resistor; a first end of the first resistor is electrically connected with a connection point between the voltage input end and the controlled end of the first switch, and a second end of the first resistor is electrically connected with a connection point between a second end of the second resistor and the first end of the first switch; the controlled end of the second switch is electrically connected with a connection point between the second end of the second resistor and the first end of the first switch, the first end of the second switch is electrically connected with a connection point between the voltage input end and the voltage output end, and the second end of the second switch is electrically connected with a connection point between the second end of the third resistor and the first end of the fourth resistor.
According to some embodiments of the invention, the first switch is a triode, the controlled terminal of the first switch is the base of the first switch, the first terminal of the first switch is the collector of the first switch, and the second terminal of the first switch is the emitter of the first switch; the second switch is a triode, the controlled end of the second switch is the base electrode of the second switch, the first end of the second switch is the collector electrode of the second switch, and the second end of the second switch is the emitter electrode of the second switch.
According to some embodiments of the invention, the clamping unit comprises a voltage dependent resistor, a first end of the voltage dependent resistor is electrically connected to the second end of the first capacitor, and a second end of the voltage dependent resistor is grounded.
According to some embodiments of the invention, the fourth resistor has a resistance of not less than 1M Ω.
According to some embodiments of the utility model, still include load resistance, load resistance's first end with the voltage output end electricity is connected, load resistance's second end ground connection.
On the other hand, according to the utility model discloses filter equipment, include the above-mentioned aspect of the utility model embodiment filter circuit.
According to the utility model discloses filter circuit and device have following beneficial effect at least: the signal filtering unit can filter the high-frequency small signal interference generated by the outside and the circuit; the active filter unit can effectively filter ripples output by the high-voltage direct-current power supply and restrain larger instantaneous current; the clamping unit can clamp the direct current output voltage at a fixed value; the filter circuit can increase the equivalent capacitance of the filter circuit without adopting a high withstand voltage value capacitor, can effectively filter ripples and high-frequency interference output by a high-voltage direct-current power supply, inhibits larger instantaneous current and enhances the loading capacity of the power supply.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
fig. 1 is a schematic circuit diagram of a filter circuit according to an embodiment of the present invention;
reference numerals:
the signal filtering unit 100, the active filtering unit 200, and the clamping unit 300.
Detailed Description
This section will describe in detail the embodiments of the present invention, the preferred embodiments of which are shown in the attached drawings, which are used to supplement the description of the text part of the specification with figures, so that one can visually and vividly understand each technical feature and the whole technical solution of the present invention, but it cannot be understood as a limitation to the scope of the present invention.
In the description of the present invention, a plurality of means are one or more, a plurality of means are two or more, and the terms greater than, less than, exceeding, etc. are understood as not including the number, and the terms greater than, less than, within, etc. are understood as including the number. If there is a description of first and second for the purpose of distinguishing technical features only, this is not to be understood as indicating or implying a relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of technical features indicated.
In the description of the present invention, unless there is an explicit limitation, the terms such as setting, installing, connecting, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meaning of the terms in the present invention by combining the specific contents of the technical solution.
On one hand, as shown IN fig. 1, the filter circuit according to the embodiment of the present invention includes a signal filtering unit 100, an active filter unit 200, a clamping unit 300, a voltage input terminal HV _ IN and a voltage output terminal HV _ OUT; the output voltage flows into the signal filtering unit 100 through the voltage input terminal HV _ IN, and the signal filtering unit 100 is used for filtering high-frequency small signal interference of the input voltage; the active filter unit 200 is configured to filter out ripples and instantaneous surges of the input voltage to form a dc output voltage; the clamping unit 300 is configured to clamp the dc output voltage at a fixed value, and output the dc output voltage through the voltage output terminal HV _ OUT; the signal filtering unit 100, the active filtering unit 200 and the clamping unit 300 are electrically connected IN sequence and are disposed between the voltage input terminal HV _ IN and the voltage output terminal HV _ OUT.
According to the embodiment of the present invention, the signal filtering unit 100 can filter the external and high frequency small signal interference generated by the circuit itself; the active filter unit 200 can effectively filter ripples output by the high-voltage direct-current power supply, suppress large instantaneous current and enhance the loading capacity of the power supply; the clamping unit 300 can clamp the dc output voltage at a fixed value, so as to provide a stable and high-voltage dc power supply with high load capability for the subsequent circuit.
Specifically, as shown IN fig. 1, IN some embodiments of the present invention, the signal filtering unit 100 includes a filter capacitor C64, a first end of the filter capacitor C64 is electrically connected to the voltage input terminal HV _ IN, a second end of the filter capacitor C64 is grounded, and the filter capacitor C64 can filter the external and the high-frequency small signal interference generated by the circuit itself.
As shown in fig. 1, in some embodiments of the present invention, the active filtering unit 200 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first capacitor C1, a second capacitor C2, a first switch Q1, and a second switch Q2; a first end of the third resistor R3 is electrically connected to the voltage input terminal HV _ IN, a second end of the third resistor R3 is electrically connected to a first end of the fourth resistor R4, and a second end of the fourth resistor R4 is grounded; the first capacitor C1 is connected with the third resistor R3 IN parallel, the first end of the second capacitor C2 is electrically connected with the voltage input end HV _ IN, and the second end of the second capacitor C2 is electrically connected with the controlled end of the first switch Q1; a first end of the second resistor R2 is electrically connected with the voltage input end HV _ IN, a second end of the second resistor R2 is electrically connected with a first end of the first switch Q1, and a second end of the first switch Q1 is electrically connected with a connection point between a second end of the third resistor R3 and a first end of the fourth resistor R4; a first end of the first resistor R1 is electrically connected with a connection point between the voltage input end HV _ IN and the controlled end of the first switch Q1, and a second end of the first resistor R1 is electrically connected with a connection point between a second end of the second resistor R2 and the first end of the first switch Q1; the controlled terminal of the second switch Q2 is electrically connected to a connection point between the second terminal of the second resistor R2 and the first terminal of the first switch Q1, the first terminal of the second switch Q2 is electrically connected to a connection point between the voltage input terminal HV _ IN and the voltage output terminal HV _ OUT, and the second terminal of the second switch Q2 is electrically connected to a connection point between the second terminal of the third resistor R3 and the first terminal of the fourth resistor R4.
The first switch Q1 and the second switch Q2 can adopt components such as a triode, a field effect transistor, a thyristor, an operational amplifier, a comparator and the like; when the first switch Q1 and the second switch Q2 adopt triodes, the controlled end of the first switch Q1 is the base electrode of the first switch Q1, the first end of the first switch Q1 is the collector electrode of the first switch Q1, and the second end of the first switch Q1 is the emitter electrode of the first switch Q1; the controlled end of the second switch Q2 is a base of the second switch Q2, the first end of the second switch Q2 is a collector of the second switch Q2, and the second end of the second switch Q2 is an emitter of the second switch Q2.
The clamping unit 300 includes a voltage dependent resistor TVS1, a first end of the voltage dependent resistor TVS1 is electrically connected to a second end of the first capacitor C1, and a second end of the voltage dependent resistor TVS1 is grounded. Note that, the clamping unit 300 may be a varistor, a TVS diode, or the like. In addition to the filtering effect, the clamping unit 300 also clamps the dc output voltage to a fixed value.
In some embodiments of the present invention, the dc output voltage clamp further includes a load resistor RL, and after a fixed value, the load resistor RL provides a stable high-voltage dc voltage for the post-stage circuit.
According to the embodiment of the present invention, the high voltage direct current of 400V (or other values) can be divided by the first resistor R1 and the second resistor R2 to form a terminal voltage Vab =10V at two points a and b; the Q1 and the Q2 can adopt NPN triodes with the same type and the current amplification factor of more than 60. Meanwhile, in order to make the amplification factors of Q1 and Q2 small and almost close to zero under the condition of direct current, the resistance of the fourth resistor R4 needs to be large enough not to be lower than 1M Ω, such as 2M Ω or other reasonable values.
As shown in fig. 1, when an interference-free signal is input and the voltage is a dc voltage of 400V, since the voltage across the first capacitor C1 cannot change suddenly, the third resistor R3 is equivalent to a short circuit, the voltage across the voltage dependent resistor TVS1 is 400V, and the voltage-stabilizing value of the voltage dependent resistor TVS1 is 390V, when the two terminals of the TVS1 are subjected to reverse transient impact, it can change the high impedance between the two terminals into low impedance at a very fast speed; at this time, the first capacitor C1 is charged through a loop formed by the first capacitor C1 and the voltage dependent resistor TVS1 and a loop formed by the first capacitor C1 and the fourth resistor R4, and reaches a stable value of 10V.
When the input voltage formed by superposing the direct-current voltage and the alternating-current interference signal is greater than 400V, on one hand, because the voltage at the two ends of the C1 can not change suddenly, the voltage value at the two ends of the voltage dependent resistor TVS1 exceeds 390V, and the two ends of the TVS1 are subjected to reverse transient impact, the high impedance between the two ends of the voltage dependent resistor TVS is changed into low impedance at a very high speed; at this time, the first capacitor C1 is charged through the first capacitor C1 and the TVS1 loop, and at the same time, Q1 and Q2 are changed from the off state to the amplification state, the base current of Q2 is increased, the output equivalent resistance between the collector and the emitter is decreased, the charging current of the loop formed by C1 and TVS1 is increased, the output ripple of the voltage is reduced through the equivalent transformation of the current source and the voltage source, and the transient surge is suppressed.
When the input voltage formed by superposing the direct current voltage and the alternating current interference signal is less than 400V, the base current of Q2 is increased and the output equivalent resistance between the collector and the emitter is reduced due to the fact that C1 discharges through a loop formed by C2 and Q1, the loop formed by C1 and R3, the loop formed by C1, R2 and Q1 and the loop formed by C1, R2 and Q2, particularly the loop formed by C1 and Q2 discharges rapidly, for a point a, according to the kirchhoff current law, the output current is increased through C1 release, the surge current is restrained, and the output ripple of the voltage is reduced through the equivalent transformation of a current source and a voltage source.
Therefore, according to the filter circuit provided by the embodiment of the utility model, the equivalent capacitance of the high-voltage direct-current power supply filter circuit is effectively increased, the capacitor with high voltage withstanding value is not needed, and only the capacitor with low voltage withstanding value is suitable, so that the cost and the volume are reduced; moreover, the circuit can effectively filter ripples and high-frequency small signal interference output by the high-voltage direct-current power supply, restrain larger instantaneous current and enhance the loading capacity of the power supply.
On the other hand, according to the utility model discloses filter equipment through adopting foretell filter circuit, can provide stable high-voltage output power, can have very big promotion to product property, improves the life of product. For example, the filter circuit is applied to a laser radar (or other devices), and a stable high-voltage direct-current power supply can be output, so that the distance measurement precision is improved, and the service life of components is prolonged.
In the description herein, references to the description of the term "one embodiment," "a further embodiment," "some specific embodiments," or "some examples," etc., mean that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.
Claims (8)
1. A filter circuit, comprising:
a voltage input terminal;
the signal filtering unit is electrically connected with the voltage input end;
the active filtering unit is electrically connected with the signal filtering unit;
the clamping unit is electrically connected with the active filtering unit;
and the voltage output end is electrically connected with the clamping unit.
2. The filter circuit according to claim 1, wherein the signal filtering unit comprises a filter capacitor, a first end of the filter capacitor is electrically connected to the voltage input end, and a second end of the filter capacitor is grounded.
3. The filter circuit according to claim 1, wherein the active filter unit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, a first switch, and a second switch; a first end of the third resistor is electrically connected with the voltage input end, a second end of the third resistor is electrically connected with a first end of the fourth resistor, and a second end of the fourth resistor is grounded; the first capacitor is connected with the third resistor in parallel, the first end of the second capacitor is electrically connected with the voltage input end, and the second end of the second capacitor is electrically connected with the controlled end of the first switch; a first end of the second resistor is electrically connected with the voltage input end, a second end of the second resistor is electrically connected with a first end of the first switch, and a second end of the first switch is electrically connected with a connection point between a second end of the third resistor and a first end of the fourth resistor; a first end of the first resistor is electrically connected with a connection point between the voltage input end and the controlled end of the first switch, and a second end of the first resistor is electrically connected with a connection point between a second end of the second resistor and the first end of the first switch; the controlled end of the second switch is electrically connected with a connection point between the second end of the second resistor and the first end of the first switch, the first end of the second switch is electrically connected with a connection point between the voltage input end and the voltage output end, and the second end of the second switch is electrically connected with a connection point between the second end of the third resistor and the first end of the fourth resistor.
4. The filter circuit according to claim 3, wherein the first switch is a triode, the controlled terminal of the first switch is the base of the first switch, the first terminal of the first switch is the collector of the first switch, and the second terminal of the first switch is the emitter of the first switch; the second switch is a triode, the controlled end of the second switch is the base electrode of the second switch, the first end of the second switch is the collector electrode of the second switch, and the second end of the second switch is the emitter electrode of the second switch.
5. The filter circuit according to claim 3, wherein the clamping unit comprises a voltage dependent resistor, a first end of the voltage dependent resistor is electrically connected to the second end of the first capacitor, and a second end of the voltage dependent resistor is grounded.
6. The filter circuit according to claim 3, wherein the fourth resistor has a resistance of not less than 1M Ω.
7. The filter circuit of claim 1, further comprising a load resistor, wherein a first end of the load resistor is electrically connected to the voltage output terminal, and a second end of the load resistor is grounded.
8. A filter arrangement, characterized by comprising a filter circuit according to any one of claims 1-7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221942965.9U CN217984850U (en) | 2022-07-22 | 2022-07-22 | Filter circuit and device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221942965.9U CN217984850U (en) | 2022-07-22 | 2022-07-22 | Filter circuit and device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN217984850U true CN217984850U (en) | 2022-12-06 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202221942965.9U Active CN217984850U (en) | 2022-07-22 | 2022-07-22 | Filter circuit and device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN217984850U (en) |
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2022
- 2022-07-22 CN CN202221942965.9U patent/CN217984850U/en active Active
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