Multichannel is isolated intrinsically safe power supply output fault recognition method
Technical field
The present invention relates to a kind of method that multichannel is isolated intrinsically safe power supply output Fault Identification that is used for.
Background technology
Flourish along with the China's coal-mine cause, the colliery electrification more and more receives people's attention, the particular surroundings in colliery; Require electrical equipment in the hazardous environment that damps such as gas, coal dust are arranged, can use safely; And no matter any fault appears in equipment, the blast that any spark that equipment produces or any thermal effect all can not cause ambient gas, and this is the essential safe type circuit; As " the heart "-power supply of electrically energized machine, the most important thing that its design just designs for electrical equipment.
The withstand voltage requirement of 500V is arranged between the intrinsically safe power supply for the isolation under the China's coal-mine; At present the duty of multiple power supplies is carried out identification cost than higher; And circuit is complicated, and the method for the intrinsically safe power supply of multichannel isolation at present output fault is to adopt multiple power supplies to detect the method for multi pass acquisition.
Summary of the invention
In view of this, the purpose of this invention is to provide a kind of multichannel and isolate intrinsically safe power supply output fault recognition method.Safe and reliable and with low cost.
The objective of the invention is to realize through following technical scheme:
This multichannel is isolated intrinsically safe power supply output fault recognition method; Be that the light emitting diode input end that all inserts optocoupler is exported on each road that will isolate intrinsically safe power supply, control the current value of the emitter-base bandgap grading output of each road optocoupler again, begin from the first via; The current value on last road is a fixed ratio k with the ratio of the current value of back one tunnel; Distinguish the difference of every road power supply with this,, the collection of magnitude of voltage is realized Fault Identification through single-chip microcomputer at last through the I/V conversion; Isolate between positive pole and the optocoupler of each road output of intrinsically safe power supply all being connected in series a voltage stabilizing diode, judge through the stabilizing voltage characteristic of voltage stabilizing diode whether the intrinsically safe power supply magnitude of voltage is normal.
Further; The method that is used to control the emitter-base bandgap grading output current value of each road optocoupler is: serial connection one emitter resistance on the emitter-base bandgap grading output terminal of each road optocoupler; The emitter resistance value on last road is 1/k with the ratio of the emitter resistance value of back one tunnel; After the process of the electric current behind emitter resistance I/V conversion, accomplish the voltage acquisition on each road by single-chip microcomputer.
The invention has the beneficial effects as follows: the present invention is fit to the fault detect location of colliery intrinsically safe power supply and selects for use, and it is safe and reliable and with low cost.
Other advantages of the present invention, target and characteristic will be set forth in instructions subsequently to a certain extent; And to a certain extent; Based on being conspicuous to those skilled in the art, perhaps can from practice of the present invention, obtain instruction to investigating of hereinafter.Target of the present invention and other advantages can realize and obtain through following instructions and claims.
Description of drawings
In order to make the object of the invention, technical scheme and advantage clearer, will combine accompanying drawing that the present invention is made further detailed description below, wherein:
Accompanying drawing is a circuit connection structure synoptic diagram of the present invention.
Embodiment
Below will carry out detailed description to the preferred embodiments of the present invention with reference to accompanying drawing.Should be appreciated that preferred embodiment has been merely explanation the present invention, rather than in order to limit protection scope of the present invention.
Multichannel of the present invention is isolated intrinsically safe power supply output fault recognition method; Said method is each road output (i.e. V1+, V1-to Vn+, Vn-among the figure) of isolating intrinsically safe power supply all to be inserted the light emitting diode input end of optocoupler, controls the current value of the emitter-base bandgap grading output of each road optocoupler again, begins from the first via; The current value on last road is a fixed ratio k with the ratio of the current value of back one tunnel; Distinguish the difference of every road power supply with this,, the collection of magnitude of voltage is realized Fault Identification through single-chip microcomputer at last through the I/V conversion; Its concrete recognition methods is: the emitter-base bandgap grading output current value of controlling each road optocoupler; Promptly on the emitter-base bandgap grading output terminal of each road optocoupler, be connected in series an emitter resistance, the emitter resistance value on last road is 1/k with the ratio of the emitter resistance value of back one tunnel, and k is 2 integral multiple; The current collection of optocoupler is fixed voltage value input (being 5v in the present embodiment) very; After the process of the electric current behind emitter resistance I/V conversion, accomplish the voltage acquisition on each road by single-chip microcomputer, because the ratio relation between the emitter resistance value; The voltage on each road that therefore collects also demonstrates corresponding ratio relation according to correspondence; Convert the levels characteristic under its normal condition the array mode of 2 systems to, the 2 system state values that the numerical value that collects through single-chip microcomputer is corresponding with it compare, thereby whether identification power supply output fault takes place and power supply output fault takes place for which.
Isolate between positive pole and the optocoupler of each road output of intrinsically safe power supply and all be connected in series a voltage stabilizing diode; Judge through the stabilizing voltage characteristic of voltage stabilizing diode whether the intrinsically safe power supply magnitude of voltage is normal; Specifically: voltage stabilizing diode is in cut-off state when undesired when power supply is exported; When power supply output voltage stabilizing diode conducting just often, judge with conducting state whether supply voltage value is normal through ending of voltage stabilizing diode like this.
As shown in the figure; Isolate the output that intrinsically safe power supply has comprised the 1 tunnel ~ the n road; Whenever including a voltage stabilizing diode on the way (is that ZD1 ~ ZDn), an optocoupler (are that U1 ~ Un), a build-out resistor (are R1 ~ Rn) and an emitter resistance (R11 ~ Rnn); Wherein the cathode output end on each road all is connected to the negative pole of voltage stabilizing diode, and the cathode output end on each road all is attached to a build-out resistor, and the positive pole of voltage stabilizing diode is attached to the positive pole of the light emitting diode of this road optocoupler; The other end of build-out resistor is attached to the negative pole of the light emitting diode of this road optocoupler, and the emitter-base bandgap grading output terminal of optocoupler is attached to emitter resistance.In the present embodiment, k gets 2, so when R11 got 1k, R22 was 2k, during to Rnn, is 2 (n-1) k.
Explanation is at last; Above embodiment is only unrestricted in order to technical scheme of the present invention to be described; Although with reference to preferred embodiment the present invention is specified, those of ordinary skill in the art should be appreciated that and can make amendment or be equal to replacement technical scheme of the present invention; And not breaking away from the aim and the scope of present technique scheme, it all should be encompassed in the middle of the claim scope of the present invention.