Prevent the safeguard structure that interface circuit of receptor equipment is damaged
Technical field
What the present invention relates to is a kind of protection circuit, particularly be a kind of acceptor equipment exist and external equipment between when having the circuit connecting relation of physics, prevent that the people from being the reversal connection power supply, the high pressure input causes the safeguard structure to the destruction of acceptor equipment.
Background technology
Growing along with electronic equipment, the transfer of data between the distinct device becomes a kind of general technical phenomena; Therefore two concept nouns have been introduced, acceptor equipment and external equipment, wherein said acceptor equipment refers to as target device corresponding with external equipment, namely is electrically connected by be combined the combination that is often referred to physically here with external equipment, realizes the mutual or monolateral transfer of data of data.For example management of power use equipment its can regard an acceptor equipment as, and management of power use personnel's hand-hold type moves poke equipment or control appliance can be to be a kind of external equipment, both can be by connecting combination, realization downloads to described hand-hold type with the data in the management of power use equipment and historical record and moves on poke equipment or the control appliance, or described hand-hold type moves poke equipment, control appliance is transferred to described management of power use equipment with upgrade data.This is very important to the fine-grained management that realizes whole power consuming administrative system, but also there are some hidden danger in this combination and data transfer mode, as for present some users intentional or accidental with combined-voltage, or adopt high pressure to introduce in the interface circuit of acceptor equipment, thereby cause the destruction to described acceptor equipment, and also do not have a kind of equipment can control this hidden danger at present.
In view of above-mentioned defective, the invention person is through research and practice obtain the present invention finally for a long time.
Summary of the invention
The objective of the invention is to, a kind of safeguard structure that prevents that interface circuit of receptor equipment is damaged is provided, in order to overcome above-mentioned defective.
For achieving the above object, the technical solution used in the present invention is, a kind of safeguard structure that prevents that interface circuit of receptor equipment is damaged is provided, and it is arranged between an acceptor equipment and the external equipment, and it comprises:
One power supply protection circuit, it has a reversal connection protective element and a pressure detection circuit; Whether it exists reversal connection and voltage to be higher than the problem of certain threshold value in order to detect described external equipment output power, and exports a connection control signal when voltage is higher than described threshold value;
One connecting circuit, it receives described connection control signal, makes to disconnect between described acceptor equipment and the external equipment when voltage is higher than described threshold value to be connected;
One data protection circuit, it has a signal receiving end and a signal output part, and one prevents the element that combined-voltage is imported; The signal that described data protection circuit receiving terminal receives described external equipment output is the pulse signal of modulation.
Wherein, the described element that prevents that combined-voltage from importing is high withstand voltage low capacity electric capacity.
Wherein, described power supply protection circuit comprises:
One reversal connection protective element, it is in order to detecting whether reversal connection of voltage, and stops the electric current input when reversal connection;
One pressure detection circuit, it exports described connection control signal in order to surpass a certain threshold value at voltage.
Preferable, described reversal connection protective element is a rectifier diode.
Wherein, described pressure detection circuit comprises:
One voltage stabilizing element, it when being higher than described threshold value, exports one first signal with the voltage that obtains;
One vent diverter, it is connected with described voltage stabilizing element, when obtaining described first signal, with described electric current shunting, and exports a secondary signal;
One connects control element; It is accepted described secondary signal and exports described connection control signal.
Preferable, described voltage stabilizing element is a voltage stabilizing didoe.
Preferable, described vent diverter is a triode, and its base stage is connected with described voltage stabilizing didoe anode, and its emitter is connected with the output of described reversal connection protective element, its grounded collector.
Preferable, described connection control element is a controllable silicon.
Preferable, described connecting circuit comprises a relay, its control end is connected with described controllable silicon anode.
Beneficial effect of the present invention is compared with the prior art, prevents that effectively acceptor equipment is subjected to artificial electric attack, has guaranteed normal the connection and transfer of data between acceptor equipment and the corresponding external equipment, has guaranteed the use safety of acceptor equipment.
Attached body explanation
Fig. 1 prevents the functional block diagram of the safeguard structure that interface circuit of receptor equipment is damaged for the present invention;
Fig. 2 prevents the circuit diagram of the safeguard structure that interface circuit of receptor equipment is damaged for the present invention.
Embodiment
Below in conjunction with accompanying drawing, be described in more detail with other technical characterictic and advantage the present invention is above-mentioned.
See also shown in Figure 1ly, it prevents the functional block diagram of the safeguard structure that interface circuit of receptor equipment is damaged for the present invention; The described safeguard structure that prevents that interface circuit of receptor equipment is damaged, it is arranged between an acceptor equipment 2 and the external equipment 1, wherein, described acceptor equipment 2 is provided with an interface circuit, carry out direct physical connection between its interface circuit by itself and described external equipment 1 generally speaking, certainly this is actually a kind of electrical connection, thereby realizes data interaction or unilateral transmission between external equipment 1 and the acceptor equipment 2.For example described acceptor equipment 2 is an ammeter, the data acquisition unit that described external equipment 1 is management of power use personnel etc.; Artificial by described acceptor equipment 2 interface circuits access combined-voltage in order to prevent, thereby cause the destruction to acceptor equipment 2, and then objectively need the present invention to prevent the setting of the safeguard structure that interface circuit of receptor equipment is damaged, it comprises: a power supply protection circuit 31, whether it exists reversal connection and overtension problem in order to detect described external equipment 1 output power, and export a connection control signal during overtension, if having the reversal connection phenomenon then stop it to be input in the described acceptor equipment in described reversal connection electric current; One connecting circuit 32, it is connected with described power supply protection circuit 31, in order to receive described connection control signal, when high pressure is imported, make to disconnect between described acceptor equipment 2 and the external equipment 1 and be connected, prevent that high pressure from destroying described acceptor equipment 2 internal circuits, if voltage, thinks then that it is safe signal less than a certain threshold value, then described connecting circuit 32 keeps be connected (electrical connection) between described acceptor equipment 2 and the external equipment 1; Sometimes described external equipment 1 will be input in the described acceptor equipment 2 by the pulse signal after the modulation, therefore in case artificial combined-voltage is input to the disorder that described acceptor equipment 2 will certainly cause acceptor equipment 2 internal datas, and can cause corresponding infringement, therefore increased a data protection circuit 33, it has a signal receiving end and a signal output part, and one prevents the element that combined-voltage is imported.
See also shown in Figure 2ly, it is the circuit diagram of the safeguard structure that prevents that interface circuit of receptor equipment is damaged.Described power supply protection circuit 31 comprises: a reversal connection protective element, and it is in order to detecting whether reversal connection of voltage, and stops the electric current input when reversal connection; One pressure detection circuit, it exports described connection control signal in order to surpass a certain threshold value at voltage.Described reversal connection protective element is a rectifier diode 3D1.Described pressure detection circuit comprises: a voltage stabilizing element, and it when being higher than described threshold value, exports one first signal with the voltage that obtains; One vent diverter, it is connected with described voltage stabilizing element, when obtaining described first signal, with described electric current shunting, and exports a secondary signal; One connects control element; It is accepted described secondary signal and exports described connection control signal.Described voltage stabilizing element is a voltage stabilizing didoe 3DW.Described vent diverter is a triode 3Q, and its base stage is connected with described voltage stabilizing didoe 3DW output, and its emitter is connected with the output of described rectifier diode 3D1, its grounded emitter.Described connection control element is a controllable silicon SCR.Described connecting circuit is a relay J, and its control end is connected with described controllable silicon SCR output; The described element of combined-voltage input that prevents is for being arranged at described signal receiving end DATAin1, DATAin2 and signal output part DATAout1, DATAout2 high withstand voltage low capacity electric capacity 3C2,3C3.
Now the course of work of this circuit is done following description, described protection circuit utilizes the characteristic of diode 3D1 forward conduction, prevents that the people from damaging for the reversal connection power supply makes the lock body internal circuit; Also undertake simultaneously and prevent artificial input ac voltage, play the effect of rectification, when artificial input ac voltage, alternating voltage is through diode 3D1 rectification, voltage stabilizing didoe 3DW conducting when direct voltage is higher, triode 3Q also conducting simultaneously, the collector electrode electronegative potential of triode 3Q, not conducting of controllable silicon SCR, not adhesive of relay J, thus the voltage of being imported into can not enter the inner circuit that damages of lock body; FPDP DATAin1, DATAin2 Data Input Interface prevent from artificially importing combined-voltage and damage the lock body internal circuit by using high withstand voltage low capacity electric capacity 3C2,3C3.
The above only is preferred embodiment of the present invention, only is illustrative for the purpose of the present invention, and nonrestrictive.Those skilled in the art is understood, and can carry out many changes to it in the spirit and scope that claim of the present invention limits, revise, even equivalence, but all will fall within the scope of protection of the present invention.