CN107863749B - A kind of cathode modulator quick current-limiting protection circuit - Google Patents
A kind of cathode modulator quick current-limiting protection circuit Download PDFInfo
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- CN107863749B CN107863749B CN201711020652.1A CN201711020652A CN107863749B CN 107863749 B CN107863749 B CN 107863749B CN 201711020652 A CN201711020652 A CN 201711020652A CN 107863749 B CN107863749 B CN 107863749B
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
- H02H3/087—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current for dc applications
Abstract
The invention discloses a kind of cathode modulator quick current-limitings to protect circuit; including current sampling circuit, grid voltage clamp circuit; 1 end of current sampling circuit is connected with 2 ends of modulator input terminal, grid voltage clamp circuit; 2 ends of current sampling circuit are connected with 3 ends of cathode high voltage power supply negative terminal, grid voltage clamp circuit, and 1 end of grid voltage clamp circuit is connected with the grid of modulator internal switch pipe.The present invention has the advantage that the present invention is controlled using grid voltage of the current-limiting protection circuit to cathode modulator internal switch pipe compared with prior art; so as to carry out quickly and effectively current-limiting protection to modulator; circuit is simple; current limliting fast response time; high reliablity; when can guarantee that sparking overcurrent occurs for klystron, the work of cathode modulator current limliting is hardly damaged.
Description
Technical field
The present invention relates to radar transmitter technical fields, and in particular to a kind of cathode current overcurrent of cathode modulation klystron
Guard method.
Background technique
Klystron is widely used in the fields such as radar, electronic countermeasure, is a kind of common power amplifying device.It is general next
It says, klystron has multiple electrodes, such as filament, cathode, collector and anode, when each electrode of klystron is plus suitable electricity
After the voltage of source, input microwave signal is effectively amplified.
The klystron radar transmitter of the overwhelming majority works in a pulsed fashion, it is therefore desirable to by pulse-modulator to velocity modulation
The power supply for managing some electrode is modulated output, and there are commonly grid modulation, anode modulation, focusing electrode modulation, control electricity
Pole modulation, cathode modulation etc..Wherein, cathode modulation, only during pulse persistance, cathode high voltage is just applied on klystron, greatly
There is no high voltage on part-time (usually more than 90%) klystron, the probability of klystron sparking reduces, and is conducive to raising system
Job stability.But by the limitation of klystron device itself, sparking can not avoid completely, once spark phenomenon occurs, it will it makes
At double or even tens times of increase at cathode modulator electric current, it is easy to cause modulator to damage.Therefore, it is necessary to quick overcurrent guarantors
Protection circuit, the sparking current limit by modulator in safe current, so that modulator be avoided to damage.
Summary of the invention
Technical problem to be solved by the present invention lies in providing a kind of cathode modulator quick current-limiting protection circuit, with gram
The failure that existing cathode modulator is easily damaged in klystron sparking is taken, has circuit simple, current limliting fast response time, work
The advantages that reliable and stable.
The present invention is to solve above-mentioned technical problem by the following technical programs: a kind of cathode modulator quick current-limiting protection
Circuit, including current sampling circuit, grid voltage clamp circuit, 1 end of current sampling circuit and modulator input terminal, grid electricity
2 ends of clamp circuit are pressed to be connected, 3 ends at 2 ends of current sampling circuit and cathode high voltage power supply negative terminal, grid voltage clamp circuit
It is connected, 1 end of grid voltage clamp circuit is connected with the grid of modulator internal switch pipe.
As the technical solution of optimization, the current sampling circuit include resistance R1, R2 ..., Rn, resistance R1, R2 and electricity
Rn series connection is hindered, 2 ends of the end R1 for connecting later as current sampling circuit, the end Rn for connecting later is as current sampling circuit
1 end.
As the technical solution of optimization, the grid voltage clamp circuit includes that metal-oxide-semiconductor V1 and transient voltage inhibit two poles
The drain electrode of pipe V2, metal-oxide-semiconductor V1 are connected with the switch tube grid inside cathode modulator, and the source electrode and transient voltage of metal-oxide-semiconductor V1 presses down
The anode of diode V2 processed, current sampling circuit 2 ends be connected, the yin of the grid of metal-oxide-semiconductor V1, transient voltage suppressor diode V2
Pole, 1 end of current sampling circuit are connected.
The process for carrying out current-limiting protection using cathode modulator quick current-limiting protection circuit is as follows:
Definition R1 ' be resistance R1, R2 ..., Rn series connection after all-in resistance, V3 ' be modulator equivalent circuit, R2 ' be modulation
Device equivalent gate drives resistance, and Rk is velocity modulation tube cathode equivalent resistance over the ground, and Ek is cathode high voltage power supply, and V1 ' is grid voltage
Clamp circuit, V2 ' are transient voltage suppressor diode；
If cathode high voltage power supply Ek voltage is UK, modulator driving signal voltage is UDRV, conduction impedance RV3’on, then
Modulator exports electric current
Since V1 ' grid voltage is the pressure drop on resistance R1 ', then
V1'GS=IO×R1'………………………(2)
When overcurrent occurs for velocity modulation tube cathode, modulator exports electric current IOTo quickly it increase, to cause V1 ' grid voltage
It increases, when reaching cut-in voltage, the conducting of V1 ' drain-source, conduction impedance RV1’on, the grid voltage of modulator V3 ' at this time
Due to V1 ' conduction impedance RV1’onLess than 100m Ω, and R2 ' is greater than 10 Ω, therefore V3 ' grid voltage is less than 1V, nothing
Method reaches cut-in voltage, modulator V3 ' shutdown, thus end modulator output electric current, after modulator output electric current is reduced to 0V,
Voltage is also 0V on R1 ', so that V1 ' is turned off, V3 ' grid voltage is restored to normal drive voltage, if over current fault disappears at this time
It removes, then modulator works normally；If klystron still has over current fault at this time, continue to repeat above-mentioned overcurrent protection movement.
It is U by the gate critical cut-in voltage that equipment product manual obtains V1 'V1’GS, it is assumed that the protection of modulator output overcurrent
Point is IOMAX, obtain the resistance value of sample resistance R1 ':
V2 ' is transient voltage suppressor diode, and when voltage increases rapidly in modulator overcurrent, R1 ', V2 ' can be in nanosecond
The maximum gate that the high impedance of two interpolars is become Low ESR, and allows the voltage clamping of two interpolars in V1 ' in the time of grade
In pole tension.
The present invention has the advantage that the present invention using current-limiting protection circuit to cathode modulator inside compared with prior art
The grid voltage of switching tube is controlled, and so as to carry out quickly and effectively current-limiting protection to modulator, circuit is simple, current limliting
Fast response time, high reliablity, it is ensured that when sparking overcurrent occurs for klystron, the work of cathode modulator current limliting is hardly damaged.
Detailed description of the invention
Fig. 1 is the circuit block diagram that cathode modulator quick current-limiting of the present invention protects circuit；
Fig. 2 is the circuit diagram of current sampling circuit in the present invention；
Fig. 3 is the circuit diagram of grid voltage clamp circuit in the present invention；
Fig. 4 is system principle analysis chart of the invention.
Specific embodiment
It elaborates below to the embodiment of the present invention, the present embodiment carries out under the premise of the technical scheme of the present invention
Implement, the detailed implementation method and specific operation process are given, but protection scope of the present invention is not limited to following implementation
Example.
As shown in Figure 1, a kind of cathode modulator quick current-limiting protection circuit, including current sampling circuit, grid voltage are embedding
Position circuit.1 end of current sampling circuit is connected with 2 ends of modulator input terminal, grid voltage clamp circuit, current sampling circuit
2 ends be connected with 3 ends of cathode high voltage power supply negative terminal, grid voltage clamp circuit, 1 end of grid voltage clamp circuit and modulation
The grid of device internal switch pipe is connected.
As shown in Fig. 2, the current sampling circuit include resistance R1, R2 ..., Rn, resistance R1, R2 and resistance Rn series connection,
Instantaneous peak value to guarantee for the electric current flowed through to be converted to the voltage signal that comparison is accurate, suitable, while when being able to bear overcurrent
Power, R1, R2 ..., each resistance of Rn the modes of multiple resistor coupled in parallel can be used and combine, resistance required for obtaining.It is whole
The effect of a current sampling circuit is to realize current sampling, will be converted to voltage by the modulator electric current of velocity modulation tube cathode, and
Guarantee that sampling voltage when reaching overcurrent protection preset value reaches the operating valve value of grid voltage clamp circuit.
As shown in figure 3, the grid voltage clamp circuit includes metal-oxide-semiconductor V1 and transient voltage suppressor diode V2.Metal-oxide-semiconductor
The drain electrode of V1 is connected with the switch tube grid inside cathode modulator, the source electrode and transient voltage suppressor diode V2 of metal-oxide-semiconductor V1
Anode, current sampling circuit 2 ends be connected, the grid of metal-oxide-semiconductor V1, the cathode of transient voltage suppressor diode V2, electric current take
1 end of sample circuit is connected.The effect of transient voltage suppressor diode V2 is to cause due to voltage spikes to inhibit overcurrent, to guarantee
Metal-oxide-semiconductor V1 grid will not excessive pressure damages.
Below with reference to Fig. 2~Fig. 4, the invention will be further described, and the resistance R1 ' in Fig. 4 system principle analysis chart is figure
Resistance R1, R2 in 2 ..., the all-in resistance after Rn series connection, be klystron cathode modulation equivalent circuit in dotted line frame in Fig. 4, wherein
V3 ' is modulator equivalent circuit, and R2 ' is that modulator equivalent gate drives resistance, and Rk is velocity modulation tube cathode equivalent resistance over the ground, Ek
For cathode high voltage power supply.V1 ' is grid voltage clamp circuit, and V2 ' is transient voltage suppressor diode.
In Fig. 4, if cathode high voltage power supply Ek voltage is UK, modulator driving signal voltage is UDRV, conduction impedance is
RV3’on, then modulator exports electric current
Since V1 ' grid voltage is the pressure drop on resistance R1 ', then
V1'GS=IO×R1'………………………(2)
When overcurrent occurs for velocity modulation tube cathode, modulator exports electric current IOTo quickly it increase, to cause V1 ' grid voltage
It increases, when reaching cut-in voltage, the conducting of V1 ' drain-source, conduction impedance RV1’on, the grid voltage of modulator V3 ' at this time
Due to V1 ' conduction impedance RV1’onLess than 100m Ω, and R2 ' is greater than 10 Ω, therefore V3 ' grid voltage is less than 1V, nothing
Method reaches cut-in voltage, modulator V3 ' shutdown, to end modulator output electric current.After modulator output electric current is reduced to 0V,
Voltage is also 0V on R1 ', so that V1 ' is turned off, V3 ' grid voltage is restored to normal drive voltage, if over current fault disappears at this time
It removes, then modulator works normally；If klystron still has over current fault at this time, continue to repeat above-mentioned overcurrent protection movement.
Therefore the defencive function is " hiccup formula " current-limiting protection.
It is U by the gate critical cut-in voltage that equipment product manual can obtain V1 'V1’GS, it is assumed that modulator output overcurrent is protected
Shield point is IOMAX, the resistance value of sample resistance R1 ' can be obtained:
In Fig. 4, V2 ' is transient voltage suppressor diode.When voltage increases rapidly in modulator overcurrent, R1 ', V2 ' energy
The high impedance of two interpolars is become into Low ESR within the time of nanosecond, absorbs up to thousands of watts of power, and makes two interpolars
Voltage clamping in the maximum gate voltage that V1 ' allows, so that V1 ' be protected not damage in modulator overcurrent.
Cathode modulator output current sampling is detected by current sampling circuit in conclusion the present invention is utilized, and
When overcurrent, cathode modulator switching tube grid voltage is reduced rapidly by grid voltage clamp circuit, turns it off, plays current limliting
Protective effect.Circuit is simple, few using device, high reliablity, realizes protection circuit miniaturization, substantially increases entire velocity modulation
The reliability and power density of pipe transmitter.
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, all in essence of the invention
Made any modifications, equivalent replacements, and improvements etc., should all be included in the protection scope of the present invention within mind and principle.
Claims (3)
1. a kind of cathode modulator quick current-limiting protects circuit, it is characterised in that: clamped including current sampling circuit, grid voltage
1 end of circuit, current sampling circuit is connected with 2 ends of modulator input terminal, grid voltage clamp circuit, current sampling circuit
2 ends are connected with 3 ends of cathode high voltage power supply negative terminal, grid voltage clamp circuit, 1 end of grid voltage clamp circuit and modulator
The grid of internal switch pipe is connected；
The current sampling circuit include resistance R1, R2 ..., Rn, resistance R1, R2 and resistance Rn series connection, the end R1 for connecting later
As 2 ends of current sampling circuit, 1 end of the end Rn for connecting later as current sampling circuit；
The grid voltage clamp circuit includes metal-oxide-semiconductor V1 and transient voltage suppressor diode V2, the drain electrode of metal-oxide-semiconductor V1 and cathode
Switch tube grid inside modulator is connected, the source electrode of metal-oxide-semiconductor V1 and anode, the current sampling of transient voltage suppressor diode V2
2 ends of circuit are connected, and the grid of metal-oxide-semiconductor V1, the cathode of transient voltage suppressor diode V2,1 end of current sampling circuit are connected.
2. a kind of cathode modulator quick current-limiting according to claim 1 protects circuit, it is characterised in that: current-limiting protection
Process is as follows:
Definition R1 ' be resistance R1, R2 ..., the all-in resistance after Rn series connection, V3 ' is modulator equivalent circuit, and R2 ' is modulator etc.
Gate driving resistance is imitated, Rk is velocity modulation tube cathode equivalent resistance over the ground, and Ek is cathode high voltage power supply, and V1 ' is that grid voltage is clamped
Circuit, V2 ' are transient voltage suppressor diode；
If cathode high voltage power supply Ek voltage is UK, modulator driving signal voltage is UDRV, conduction impedance RV3’on, then modulate
Device exports electric current
Since V1 ' grid voltage is the pressure drop on resistance R1 ', then
V1'GS=IO×R1'………………………(2)
When overcurrent occurs for velocity modulation tube cathode, modulator exports electric current IOTo quickly it increase, so that V1 ' grid voltage is caused to increase,
When reaching cut-in voltage, the conducting of V1 ' drain-source, conduction impedance RV1’on, the grid voltage of modulator V3 ' at this time
Due to V1 ' conduction impedance RV1’onLess than 100m Ω, and R2 ' is greater than 10 Ω, therefore V3 ' grid voltage is less than 1V, Wu Fada
To cut-in voltage, modulator V3 ' shutdown, to end modulator output electric current, after modulator output electric current is reduced to 0V, on R1 '
Voltage is also 0V, so that V1 ' is turned off, V3 ' grid voltage is restored to normal drive voltage, if over current fault is eliminated at this time,
Modulator works normally；If klystron still has over current fault at this time, continue to repeat above-mentioned overcurrent protection movement.
3. a kind of cathode modulator quick current-limiting according to claim 2 protects circuit, it is characterised in that: produced by equipment
The gate critical cut-in voltage that product handbook obtains V1 ' is UV1’GS, it is assumed that modulator output overcurrent protection point is IOMAX, obtain sample resistance
The resistance value of R1 ':
V2 ' is transient voltage suppressor diode, and when voltage increases rapidly in modulator overcurrent, R1 ', V2 ' can be in nanosecond
The largest gate electricity that the high impedance of two interpolars is become into Low ESR in time, and allows the voltage clamping of two interpolars in V1 '
In pressure.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711020652.1A CN107863749B (en) | 2017-10-26 | 2017-10-26 | A kind of cathode modulator quick current-limiting protection circuit |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711020652.1A CN107863749B (en) | 2017-10-26 | 2017-10-26 | A kind of cathode modulator quick current-limiting protection circuit |
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| Publication Number | Publication Date |
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| CN107863749A CN107863749A (en) | 2018-03-30 |
| CN107863749B true CN107863749B (en) | 2019-07-05 |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN112260246B (en) * | 2020-11-09 | 2021-10-26 | 珠海格力电器股份有限公司 | Control method of current limiting control circuit and electrical system |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN203813431U (en) * | 2014-04-21 | 2014-09-03 | 唐绍根 | Current limiting protection circuit based on MOS tube grid voltage control |
| CN106033880A (en) * | 2015-03-09 | 2016-10-19 | 何曙光 | Hiccup type protection circuits for DC power supply |
| CN205958062U (en) * | 2016-08-15 | 2017-02-15 | 成都众山科技有限公司 | Wireless liquid level flow transmitter |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5696074B2 (en) * | 2012-03-16 | 2015-04-08 | 株式会社東芝 | Semiconductor device |
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- 2017-10-26 CN CN201711020652.1A patent/CN107863749B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN203813431U (en) * | 2014-04-21 | 2014-09-03 | 唐绍根 | Current limiting protection circuit based on MOS tube grid voltage control |
| CN106033880A (en) * | 2015-03-09 | 2016-10-19 | 何曙光 | Hiccup type protection circuits for DC power supply |
| CN205958062U (en) * | 2016-08-15 | 2017-02-15 | 成都众山科技有限公司 | Wireless liquid level flow transmitter |
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| CN107863749A (en) | 2018-03-30 |
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