A kind of circuit protecting device with excessively stream and over-voltage protecting function
Technical field
The present invention relates to a kind of circuit protecting device with excessively stream and over-voltage protecting function, the circuit protecting device can be with
The timely chopping current in current anomaly or electric voltage exception.
Background technology
In telecommunication transmission system, because the distance that the communications cable is set up is generally all long, it can largely send out
The situation that raw power line surprisingly overlaps, when power line is directly taken on the communications cable due to fortuitous event, it is possible to can occur
Overcurrent, overvoltage phenomenon.Heavy current invading can threaten to the safety of the calculator room equipments such as distributing frame, data switching exchane, seriously
Shi Keneng can also trigger fire incident, cause serious consequence.So need protection location prevent the person and equipment by
The injury of electric current, overvoltage, protection location can be acted in overcurrent, overvoltage intrusion, and protection is provided to communication equipment.At present
The protection scheme of traditional route protection unit is the discrete PTC with positive temperature coefficient effect electrically discrete transient states in parallel
Suppress diode TVS, this protection scheme is in printed substrate(PCB)Upper area occupied is bigger, especially in some conditions
(High voltage, low current)The situation that over-voltage protection element burns can occur, trigger second accident.Integrated Protection Scheme for Transmission Line
It can prevent because over-voltage protection element burns the second accident of initiation, and discrete component can be made up well and be taken on PCB
The big deficiency of area.
The content of the invention
It is an object of the invention to:A kind of circuit protecting device with excessively stream and over-voltage protecting function is provided, so as to
Timely chopping current when current anomaly or electric voltage exception.
The object of the invention is realized by following proposal:A kind of circuit protecting device with excessively stream and over-voltage protecting function,
Including:One-level excessively stream and over-voltage protection element, two level over-voltage protection element, rear class functional circuit, wherein, described one-level excessively stream
And over-voltage protection element is electrically coupled with described rear class functional circuit and is connected, described two level over-voltage protection element is electrically in parallel
Between described excessively stream and over-voltage protection element and described rear class functional circuit.The present invention is different in current anomaly or voltage
Timely chopping current when often.Particularly with high voltage, low-current case, there is more superior guarantor compared to traditional protection scheme
Protect performance.
Described one-level excessively stream and over-voltage protection element are selected from the PTC-element with positive temperature coefficient effect and with overvoltage
The Transient Suppression Diode TVS of the defencive function combination of two or more.
Described two level over-voltage protection element is selected from Transient Suppression Diode TVS, gas with surge protection function and put
Fulgurite GDT, surge suppress IGCT TSS one or more combinations.
Described rear class functional circuit can be the one or more such as DC-DC conversion modules, signaling module, PWM module
Combination.
The present invention is advantageous in that:Can in current anomaly and electric voltage exception in time voltage clamping in safe range simultaneously
And chopping current, until failure is released from, so as to protect electronic equipment and circuit.
Brief description of the drawings
Fig. 1 is the Protection Scheme for Transmission Line schematic diagram for having in embodiment 1 excessively stream and over-voltage protecting function;
Fig. 2 is the Protection Scheme for Transmission Line schematic diagram for having in embodiment 2 excessively stream and over-voltage protecting function;
11 --- one-level excessively stream and over-voltage protection element;
12 --- two level over-voltage protection element;
13 --- rear class functional circuit;
14 --- there is the PTC-element of positive temperature coefficient effect;
15 --- Transient Suppression Diode TVS;
21 --- one-level excessively stream and over-voltage protection element;
22 --- two level over-voltage protection element;
23 --- rear class functional circuit;
24th, 26 --- there is the PTC-element one, two of positive temperature coefficient effect;
25 --- two-way Transient Suppression Diode TVS.
Embodiment
Below by way of specific embodiment, the present invention is described in further detail.
Embodiment 1
Fig. 1 is a kind of Protection Scheme for Transmission Line schematic diagram with excessively stream and over-voltage protecting function in the present invention.It includes one-level mistake
Stream and over-voltage protection element 11, two level over-voltage protection element 12, rear class functional circuit 13.The one-level excessively stream and overvoltage protection member
Part 11 includes PTC-element 14 and Transient Suppression Diode TVS 15 with positive temperature coefficient effect, and one-level excessively stream and overvoltage are protected
Protection element 11 is electrically coupled with rear class functional circuit 13 and is connected, two level over-voltage protection element 12 be electrically connected in parallel on one-level excessively stream and
Between over-voltage protection element 11 and rear class functional circuit 13.
Embodiment 2
Fig. 2 is a kind of Protection Scheme for Transmission Line schematic diagram with excessively stream and over-voltage protecting function in the present invention.It includes one-level mistake
Stream and over-voltage protection element 21, two level over-voltage protection element 22, rear class functional circuit 23.The one-level excessively stream and overvoltage protection member
Part 21 includes PTC-element one, 2 24,26 and two-way Transient Suppression Diode TVS 25 with positive temperature coefficient effect, one-level
Excessively stream and over-voltage protection element 21 are electrically coupled with rear class functional circuit 23 to be connected, and two level over-voltage protection element 22 is electrically connected in parallel on
Between one-level excessively stream and over-voltage protection element 21 and rear class functional circuit 23.