Summary of the invention
In view of this, the object of the present invention is to provide a kind of fan-status feed back control system and method thereof, solving prior art needs microprocessor to participate in calculating, the defect that circuit cost is high, realize rotation speed of the fan monitoring by simple circuit structure, really accomplish to design simplification, low cost, non-maintaining.
In order to realize foregoing invention object, the present invention specifically provides a kind of technic relization scheme of fan-status feed back control system, a kind of fan-status feed back control system, comprising: information gathering decision circuitry, state signal output circuit and state signal display circuit.Described information gathering decision circuitry comprises one-level comparison circuit, high-pass filtering circuit, secondary comparison circuit and frequency-voltage conversion circuit further.The rotation speed of the fan input signal of voltage functuation is converted to stable low and high level signal by described one-level comparison circuit, described low and high level signal carries out after high-pass filtering process through described high-pass filtering circuit, export described frequency-voltage conversion circuit again to and carry out voltage to frequency conversion, input after described secondary comparison circuit and reference voltage compare through the fixed voltage signal of voltage to frequency conversion and obtain fan-status signal, described fan-status signal exports described state signal output circuit and state signal display circuit to, is used to indicate fan-status.
Preferably, described fan-status feed back control system comprises N group information gathering decision circuitry for detecting the rotation speed of the fan input signal corresponding with described information gathering decision circuitry of more than two-way, N >=2.Described state signal output circuit comprises N number of voltage compare path corresponding with rotation speed of the fan input signal way, and described state signal display circuit comprises N number of fan-status indicating circuit corresponding with rotation speed of the fan input signal way.
Preferably, the rotation speed of the fan input signal of described voltage functuation with one to the low and high level signal of determining voltage signal stable output after described one-level comparison circuit compares, described determining voltage signal of giving is determined by the minimum pressure reduction of rotation speed of the fan input signal, and is obtained by electric resistance partial pressure by power supply circuits.
Preferably, described high-pass filtering circuit comprises electric capacity C1 and resistance R2, and described electric capacity C1 is in parallel with resistance R2, and the capacitance C of described electric capacity C1 is given by the following formula:
r is that the resistance of resistance R2 and the appearance of electric capacity C1 hinder sum, and n is rotation speed of the fan.
Preferably, described state signal output circuit comprises triode and relay further, and described triode is connected with the secondary comparison circuit output terminal organizing described information gathering decision circuitry respectively.When described information gathering decision circuitry all exports high level, then described triode ON, described relay adhesive, feeds back a weak electric signal by the contact of described relay, or drags down the level signal provided in control gear, points out all fan works normal; When output signal Zhong You mono-tunnel of the secondary comparison circuit of the described information gathering decision circuitry of many groups is low level, then described triode cut-off, cause described relay adhesive to disconnect, corresponding weak electric signal disconnects or level signal is elevated, and prompting has fan work abnormal.
Preferably, the reference voltage Uc' of described secondary comparison circuit is determined by following formula:
Uc' ≈ V
0+ (V
1-V
0) × (1-exp
-t/R ' C '), wherein, V
0for the initial voltage value on electric capacity in frequency-voltage conversion circuit, V
1for the magnitude of voltage on t electric capacity, t is the duration of charge, and R ' is the resistance value of resistance in frequency-voltage conversion circuit, the capacitance that C ' is electric capacity.
Preferably, the reference voltage Uc' of described secondary comparison circuit is less than or equal to 3.6V.
Preferably, described state signal display circuit comprises comparator and display unit, the corresponding described display unit of each road rotation speed of the fan input signal, the low and high level exported according to described information gathering decision circuitry and reference voltage Uc' compare, and change output state, display unit are lighted or extinguishes, when fan-status is normal, corresponding display unit is lighted, and when fan-status is abnormal, corresponding display unit extinguishes.
The present invention also specifically provides a kind of technic relization scheme of fan-status feedback in addition, a kind of fan-status feedback, fan-status feed back control system comprises: information gathering decision circuitry, state signal output circuit and state signal display circuit, described information gathering decision circuitry comprises one-level comparison circuit, high-pass filtering circuit, secondary comparison circuit and frequency-voltage conversion circuit further, and described controlling method comprises the following steps:
(A): the rotation speed of the fan input signal of voltage functuation is converted to stable low and high level signal by described one-level comparison circuit;
(B): described high-pass filtering circuit carries out high-pass filtering process to the low and high level signal that described one-level comparison circuit exports;
(C): the low and high level signal through high-pass filtering process is carried out voltage to frequency conversion by described frequency-voltage conversion circuit, and exports fixed voltage signal;
(D): input after described secondary comparison circuit and reference voltage compare through the fixed voltage signal of voltage to frequency conversion and obtain fan-status signal, described fan-status signal exports described state signal output circuit and state signal display circuit to, is used to indicate fan-status.
Preferably, the rotating speed of described fan is controlled at 800 ~ 1200 turns.
A kind of fan-status feed back control system provided by enforcement the invention described above and the technological scheme of method thereof, have following technique effect:
(1) the invention solves prior art can only by the high cost scheme of processor and rotating speed Acquisition Circuit, realized the monitoring of rotation speed of the fan by simple comparator and band-pass circuit, and fan failure state feedback function can be realized by the display unit of relay and equipment itself simultaneously;
(2) the present invention uses two-way comparison circuit to form, rotation speed of the fan pulse signal is converted to voltage signal compare, rotation speed of the fan monitoring is realized by stop voltage signal amplitude, and the fault feedback of display unit and relay weak electric signal is realized by another road comparator, achieve strong and weak electricity, mutually isolated between reliable circuit and unreliable circuit;
(3) the whole control gear of the present invention participates in without the need to processor, without the need to programming, can calculate the mean free error time by hardware, really achieves low cost, non-maintaining, and greatly simplify the system of device.
Embodiment
For the purpose of quoting and know, by the technical term hereinafter used, write a Chinese character in simplified form or abridge and be described below:
MCU:MicroControlUnit, microcontroller;
FPGA:FieldProgrammableGateArray, i.e. field programmable gate array;
LED:LightEmittingDiode, light emitting diode;
ATP:AutomaticTrainProteciton, train protection system, also claims time interval between to trains system;
SMD:SurfaceMountedDevices, surface mount;
F/V transducer: frequency/voltage converter;
For making the object of the embodiment of the present invention, technological scheme and advantage clearly, below in conjunction with the accompanying drawing in the embodiment of the present invention, technological scheme in the embodiment of the present invention is clearly and completely described, obviously, described embodiment is only a part of embodiment of the present invention, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.
As shown in accompanying drawing 1 to accompanying drawing 6, give the specific embodiment of a kind of fan-status feed back control system of the present invention and method thereof, below in conjunction with the drawings and specific embodiments, the invention will be further described.
The embodiment of a kind of fan-status feed back control system as shown in accompanying drawing 1 and accompanying drawing 3, comprising: information gathering decision circuitry 1, state signal output circuit 2 and state signal display circuit 3.Information gathering decision circuitry 1 comprises one-level comparison circuit 10, high-pass filtering circuit 11, secondary comparison circuit 12 and frequency-voltage conversion circuit 13 further.Wherein, one-level comparison circuit 10 and secondary comparison circuit 12 adopt LM139D comparator.The rotation speed of the fan input signal of voltage functuation is converted to stable low and high level signal by one-level comparison circuit 10, low and high level signal is after high-pass filtering circuit 11 carries out high-pass filtering process, export frequency-voltage conversion circuit 13 again to and carry out voltage to frequency conversion, after the fixed voltage signal input secondary comparison circuit 12 of voltage to frequency conversion compares with reference voltage, obtain fan-status signal.Fan-status signal exports state signal output circuit 2 and state signal display circuit 3 to, is used to indicate fan-status.
Fan-status feed back control system comprises the information gathering decision circuitry 1 of N group for detecting the rotation speed of the fan input signal corresponding with information gathering decision circuitry 1 of more than two-way, N >=2.State signal output circuit 2 comprises N number of voltage compare path corresponding with rotation speed of the fan input signal way, and state signal display circuit 3 comprises N number of fan-status indicating circuit corresponding with rotation speed of the fan input signal way.As the typical mode of execution of one, 1 fan unit block comprises 4 fans, and the fan-status feed back control system shown in the present embodiment specifically comprises 4 groups of information gathering decision circuitry 1 for detecting the rotation speed of the fan input signal corresponding with information gathering decision circuitry 1 on 4 tunnels.State signal output circuit 2 comprises voltage compare path corresponding to 4 tunnels, and state signal display circuit 3 comprises the 4 tunnels fan-status indicating circuit corresponding with rotation speed of the fan input signal way.
As shown in Figure 3, the rotation speed of the fan input signal Ua and of voltage functuation gives the low and high level signal of determining voltage signal Uc stable output after one-level comparison circuit 10 compares.Be peak value be any voltage value to determining voltage signal Uc, there is the electrical pulsing signal of certain dutycycle, and obtained by electric resistance partial pressure by power supply circuits.Generally, determined by the minimum pressure reduction of rotation speed of the fan input signal to determining voltage signal Uc, can have a detailed description in the usage data document of selected fan.
As the typical mode of execution of one, the comparative result that one-level comparison circuit 10 exports, is transformed into signal Ub by the high-pass filtering circuit 11 be made up of electric capacity C1 and resistance R2.The electric capacity C1 of high-pass filtering circuit 11 is in parallel with resistance R2, and the minimum speed limiting fan is 1000(± 20%) turn, the capacitance C of electric capacity C1 is given by the following formula:
As shown in Figure 4, in figure, Us
highfor output voltage high level, Us
lowfor output voltage low level, rotation speed of the fan formula is as follows:
Rotational frequency f=2 × the n/60Hz of fan
Wherein, n is rotation speed of the fan.
The capacitance estimation equation of electric capacity C1 is as follows:
Wherein, C is the capacitance of electric capacity C1, and π gets the electric capacity capacitive reactance sum of resistance that 3.14, R is resistance R2 and electric capacity C1, and f is the rotational frequency of fan.Wherein, the electric capacity capacitive reactance Xc of electric capacity C1 is the resistance value of electric capacity Opposed Current: formula: Xc=1/(ω × C), ω is angular velocity, and C is capacitance.The capacitance estimation equation (formula all uses international unit) of electric capacity C1 can be drawn by above two formula:
Can be calculated, the capacitance of electric capacity C1 is 0.048 μ F, and therefore, the capacitance that C1 is held in power taking is 0.047 μ F.
One-level comparison circuit 10 pairs of fan rotating speed signals output amplitudes limit, and the fan rotating speed signals that fan unit block adopts is square signal, and high level fluctuates with the difference of rotating speed and input voltage, and amplitude range is 2.5V ~ 5V.In like manner, low level amplitude range is 0V ~ 0.4V, therefore the minimum pressure reduction of frequency signal is 2.1V.Because fan-status feed back control system adopts the power supply circuits of 24V, therefore can pass through electric resistance partial pressure, and then obtain judging voltage U c.The reference voltage Uc' of secondary comparison circuit 12 is determined by following formula further:
Uc'≈V
0+(V
1-V
0)×(1-exp
-t/R′C′)
Frequency-voltage conversion circuit 13 comprises electric capacity C2 and resistance R3 further, wherein, and V
0for the initial voltage value on electric capacity C2, V
1for the magnitude of voltage on t electric capacity C2, t is the duration of charge, and R ' is the resistance value of resistance R3, and C ' is the capacitance of electric capacity C2.
Rotation speed of the fan is sent to higher than the comparative result of 1000 turns the frequency-voltage conversion circuit 13 be made up of diode D1, electric capacity C2 and resistance R3 and converts fixed voltage Ud to, and is delivered to secondary comparison circuit 12.Discharge and recharge frequency due to electric capacity C2 is change, by capacitor charge and discharge formula Uc' ≈ V
0+ (V
1-V
0) × (1-exp
-t/RC), can show that fan is when rotating speed is 1000 ~ 2800 turns, the approximate extents of one-level comparison circuit 10 output voltage is 3.4 ~ 5.0V(± 5%), therefore the reference voltage Uc ' getting secondary comparison circuit 12 is less than or equal to 3.6V compares, and draws fan-status signal.Output rusults is: when the rotating speed of fan is higher than (containing 1000 turns) when 1000 turns, secondary comparison circuit 12 exports 24V high level; When the rotating speed of fan is lower than 1000 turns, secondary comparison circuit 12 exports 0V low level.
As shown in Figure 5, state signal output circuit 2 comprises triode Q9 and relay K 2 further, and triode Q9 gathers decision circuitry 1 respectively secondary comparison circuit 12 output terminal with multipacket message is connected.State signal output circuit 2 is exported by 4 comparators and is jointly connected to triode Q9, and 4 comparators judge that corresponding signal acquisition circuit output level is high level or low level respectively.When information gathering decision circuitry 1 all exports high level, then triode Q9 conducting, relay K 2 adhesive, feeds back a weak electric signal by the contact of relay K 2, or dragging down the level signal provided in control gear, all fan works in prompting fan unit block are normal; Output signal Zhong You mono-tunnel gathering the secondary comparison circuit 12 of decision circuitry 1 when multipacket message is low level, then triode Q9 ends, cause relay K 2 adhesive to disconnect, corresponding weak electric signal disconnects or level signal is elevated, and has fan work abnormal in prompting fan unit block.
As shown in Figure 6, state signal display circuit 3 comprises comparator and display unit further, the corresponding display unit of each road rotation speed of the fan input signal, the low and high level exported according to information gathering decision circuitry 1 and reference voltage Uc' compare, change output state, display unit is lighted or extinguishes.When fan-status is normal, corresponding display unit is lighted, and when fan-status is abnormal, corresponding display unit extinguishes.In this specific embodiment, comparator adopts a LM139D comparator chip, display unit adopts LED(LightEmittingDiode, light emitting diode) lamp, the corresponding LED lamp of each unit, low and high level and reference voltage according to gathering decision circuitry output compare, and change output state, LED are lighted or extinguishes.
As shown in Figure 2, a kind of embodiment of fan-status feedback, fan-status feed back control system comprises: information gathering decision circuitry 1, state signal output circuit 2 and state signal display circuit 3, information gathering decision circuitry 1 comprises one-level comparison circuit 10, high-pass filtering circuit 11, secondary comparison circuit 12 and frequency-voltage conversion circuit 13 further, and controlling method comprises the following steps:
(A): the rotation speed of the fan input signal of voltage functuation is converted to stable low and high level signal by one-level comparison circuit 10;
(B): the low and high level signal that high-pass filtering circuit 11 pairs of one-level comparison circuits 10 export carries out high-pass filtering process;
(C): the low and high level signal through high-pass filtering process is carried out voltage to frequency conversion by frequency-voltage conversion circuit 13, and exports fixed voltage signal;
(D): after the fixed voltage signal input secondary comparison circuit 12 of voltage to frequency conversion compares with reference voltage, obtain fan-status signal, fan-status signal exports state signal output circuit 2 and state signal display circuit 3 to, is used to indicate fan-status.When frequency comparative result meets the demands, light fan unit block LED relay closes state signal; When frequency comparative result does not meet the demands, extinguish fan unit block LED relay off state signal.
As preferably mode of execution a kind of in the present embodiment, the rotating speed of fan is controlled at 800 ~ 1200 turns.
For the calculating of rotation speed of the fan resonable degree, as: a new design radiation system, easily causes the hidden danger of heat exchange deficiency for improveing former heat radiation system.Former radiation system uses 2 ventilations to be 150m
3the fan of/h, wherein, the air quantity that AF provides for single fan, when not considering windage, the air quantity that two fan unit blocks can provide is:
AF
total0=4×AF=4×150m
3/h=600m
3/h
New design radiation system adopts 4 ventilations to be 170m
3the fan of/h, when not considering windage, the air quantity that four fans can provide is:
AF
total1=8×AF=8×170m
3/h=1360m
3/h
If fan unit block ventilation arrives 600m
3be unreasonable ventilation during/h, then when not considering windage, 4 fan mean speeds of new departure radiation system are reduced to 44% of rated speed, then enter " danger " state, and ventilation now may cause system plate operating temperature too high.Formula is:
If rotation speed of the fan is S, new fan unit block fan's rated speed is S
new0, hazardous condition rotating speed is S
new1, ventilation fan amount and rotating speed in direct ratio, scale factor is t, obtains formula as follows:
S
new1=t×S
new0=(AF
total0÷AF
total1)×100%×S
new0=600/1360×100%×2800=1260(RPM)
Therefore the rotating speed of fan controls at 1000 turns (± 20%) by control gear, realistic demand.
The rotational speed pulse signal of fan is converted to voltage signal by two-way comparison circuit by the present invention, compare with reference potential, fan-status is then exported good higher than reference potential, and light the LED of corresponding fan-status, corresponding LED is then extinguished lower than reference potential, export radiation system status information by relay simultaneously, enable system obtain radiation system status information in real time, thus realize the function of rotation speed of the fan monitoring.The present invention adopts two-way comparison circuit, rotation speed of the fan pulse signal is converted to voltage signal compare, rotation speed of the fan monitoring is realized by stop voltage signal amplitude, and the weak electric signal fault feedback of LED and relay is realized by another road comparator of state signal output circuit 2, realize strong and weak electricity, mutually isolated between reliable circuit and unreliable circuit.Whole device participates in without the need to processor, without the need to programming, can calculate the mean free error time, really achieve object that is non-maintaining, low cost by hardware.The technological scheme that the specific embodiment of the invention describes can monitor the state of 4 fans simultaneously, and is restricted by the rotary speed information incoming frequency of 4 fans on 4 tunnel information gathering decision circuitry, 1 pair of fan unit block.When rotation speed of the fan is higher than limit value; fan-status feed back control system is to ATP(AutomaticTrainProtection; train protection system; also time interval between to trains system is claimed) output state information; and light by 4 line state signal display circuits 3 LED that on fan unit block, each fan is corresponding; when the rotating speed of any one fan is lower than limit value; fan-status feed back control system stops to ATP output state information; extinguish to should the LED of fan on fan unit block, thus reach the object that fan-status is judged.
The present invention can also use F/V transducer, carries out simple frequency-voltage transitions, as used the F/V conversion chips such as LM2917, realizes function of the present invention.But, use F/V transducer cannot realize fan-status feed back control system fan detecting portion and signal acquisition part divide between isolation, lower in Security.Simultaneously, comparator in the middle of the specific embodiment of the invention can use the comparator of other any models (as changed 74 series of comparisons devices into by LM series of comparisons device, 2 road comparators change to 4 road comparators etc. mode), capacitance kind device, as ceramic condenser being replaced by tantalum electric capacity, SMD(SurfaceMountedDevices, surface mount) electric capacity is replaced by plug-in mounting electric capacity etc.
In this specification, each embodiment adopts the mode of going forward one by one to describe, and what each embodiment stressed is the difference with other embodiments, between each embodiment identical similar portion mutually see.
The above is only preferred embodiment of the present invention, not does any pro forma restriction to the present invention.Although the present invention discloses as above with preferred embodiment, but and be not used to limit the present invention.Any those of ordinary skill in the art, when not departing from Spirit Essence of the present invention and technological scheme, the Method and Technology content of above-mentioned announcement all can be utilized to make many possible variations and modification to technical solution of the present invention, or be revised as the Equivalent embodiments of equivalent variations.Therefore, every content not departing from technical solution of the present invention, according to technical spirit of the present invention to any simple modification made for any of the above embodiments, equivalent replacement, equivalence change and modification, all still belongs in the scope of technical solution of the present invention protection.