Summary of the invention
In view of above content, be necessary to provide a kind of filter suppressing resonance, to increase reliability and the fail safe of circuit.
A kind of filter suppressing resonance, be connected between a power supply and a load, described filter is used for after the voltage filter that exported by described power supply to described load supplying, described filter comprises first and second inductance, first and second electric capacity, one switch and a controller, the first end of described first inductance is connected to the voltage output end of described power supply, the first end of described first inductance is also by described first capacity earth, the first end of described first inductance connects the first end of described switch, second end of described switch connects the first end of described second inductance, second end of described second inductance connects the second end of described first inductance, second end of described first inductance connects the control end of described switch by described controller, second end of described first inductance is also by described second capacity earth, second end of described first inductance is also connected to described load, when the second terminal voltage that described controller senses described first inductance is increased sharply, the first end that described controller controls described switch is communicated with the second end, when described controller sense the second terminal voltage of described first inductance normal after, described controller controls the first end of described switch and the second end disconnects.
Above-mentioned filter changes the resonant frequency point of described filter to suppress resonance utilizing described second inductance when resonance occurs, the described switch of normal rear disconnection is recovered to recover original design of filter at resonance, effectively inhibit resonance phenomena, effectively increase reliability and the fail safe of circuit.
Accompanying drawing explanation
Fig. 1 is the circuit diagram of existing filter work.
Fig. 2 is the oscillogram of existing filter frequencies and amplitude relation.
Fig. 3 is the circuit diagram that the present invention can suppress the better embodiment of the filter of resonance.
Main element symbol description
Filter |
10 |
Power supply |
20 |
Load |
30 |
Switch |
11 |
Controller |
12 |
Inductance |
L1、L2 |
Electric capacity |
C1、C2 |
Following embodiment will further illustrate the present invention in conjunction with above-mentioned accompanying drawing.
Embodiment
Below in conjunction with accompanying drawing and better embodiment, the present invention is described in further detail:
Please refer to Fig. 3, the present invention can suppress the filter 10 of resonance to be connected between a power supply 20 and a load 30, and described filter 10 is powered for giving described load 30 after the voltage filter that exported by described power supply 20.
Described filter 10 comprises inductance L 1, L2, electric capacity C1, C2, switch 11 and a controller 12.The first end of described inductance L 1 is connected to the voltage output end of described power supply 20, the earth terminal ground connection of described power supply 20.The first end of described inductance L 1 is also by electric capacity C1 ground connection, the first end of described inductance L 1 connects the first end of described switch 11, second end of described switch 11 connects the first end of described inductance L 2, second end of described inductance L 2 connects the second end of described inductance L 1, second end of described inductance L 1 is connected to the control end of described switch 11 by described controller 12, second end of described inductance L 1 is also by described electric capacity C2 ground connection, second end of described inductance L 1 is also connected to described load 30, the earth terminal ground connection of described load 30.
When described filter 10 normally works and the electric voltage frequency that the voltage output end of described power supply 20 exports not yet arrives the resonant frequency point of described filter 10, described controller 12 does not work, first end and second end of described switch 11 are in off-state, and the voltage that the voltage output end of described power supply 20 exports is powered to described load 30 after described inductance L 1, electric capacity C1, C2 filtering.
When the electric voltage frequency that the voltage output end of described power supply 20 exports arrives the resonant frequency point of described filter 10, the voltage that described controller 12 senses the second end of described inductance L 1 increases sharply, the first end that described controller 12 controls described switch 11 is communicated with the second end, and the voltage that the voltage output end of described power supply 20 exports is powered to described load 30 after described inductance L 1, L2 and described electric capacity C1, C2 filtering.Now, the resonance frequency of described filter 10 changes along with the change of inductance value in filter 10 circuit, that is, the voltage that now voltage output end of described power supply 20 exports is inhibited through the filtered resonance of described filter 10.
When described controller 12 sense the voltage resume of the second end of described inductance L 1 normal after, described controller 12 controls the first end of described switch 11 and the second end disconnects, and the voltage that the voltage output end of described power supply 20 exports continues to power to described load 30 after described inductance L 1 and described electric capacity C1, C2 filtering.
Above-mentioned filter 10 changes the resonant frequency point of described filter 10 to suppress resonance utilizing inductance L 2 when resonance occurs, recover the normal rear connection disconnecting described inductance L 2 at resonance, the voltage that the voltage output end of described power supply 20 exports continues to power to described load 30 after described inductance L 1 and described electric capacity C1, C2 filtering.Described filter 10 effectively inhibits resonance phenomena.
As can be seen from description above, described switch 11 is in connection or off-state by the control of described controller 12, in other execution modes, described switch can be an electronic switch, as triode or field effect transistor, the control end of described electronic switch is connected with described controller, and the first end of described electronic switch and the second end connect the first end of described inductance L 1 and the first end of described inductance L 2 respectively, and described electronic switch is in connection or off-state by the control of described controller 12.