CN2045861U - Control device for general electric system - Google Patents

Abstract

The utility model discloses a control device for the general electric system which adopts a current transformer and a time-base circuit to work according to the electric current of electric equipment. Compared with the protection method of a bimetallic or a thermistor, the utility model has the advantages of strong versatility, high precision, convenient operation, small size, and short response time; also, the operating condition and the high-voltage isolation of the device can be detected, the control value can be freely set, an early warning can be made, the control signal can be directly exchanged with the outside, etc. The control device for the general electric system can be formed to the automatic control systems with various functions without other sensors; the cost is much lower than a computer controlled system.

Description

Control device for general electric system

The utility model relates to a kind of electrical control gear, particularly comes electronic installation that electrical equipment and system thereof are controlled according to the electric current of electrical equipment.

Three-phase electrical equipment and system thereof such as threephase asynchronous machine and dragging system thereof all require to be equipped with various automatic control functions, such as overload protection and start, close certain equipment automatically according to the variation of load.Existing electrothermal relay and thermistor can't adapt to higher control requirement.

The purpose of this utility model provides a kind of highly versatile, control function is many, operation and maintenance is convenient, the response time is short, lower-cost, can come electronic installation that it is controlled according to the electric current of electrical equipment.Below often abbreviate general purpose controller as.

Its solution is: the electric current that detects electrical equipment with special-purpose current transformer, the current signal that records is introduced the reset terminal of 555 time base circuits or is directly received its trigger end behind level conversion and control setting electric resistance partial pressure, and time base circuit makes the executive component action carry out automatic control with sound and light alarm or Switching power when electric current reaches setting value.Further, relevant work or the shut-in time of utilizing the RC circuit to remember electrical equipment or system also carried out various controls in view of the above.Describe below by embodiment.Described each scheme can make up as required.

Fig. 1,2,3 provides a general purpose controller embodiment Fig. 1 who is used for threephase asynchronous machine overload and open-phase protection for principle of work, can be divided into four parts.(1) detect the rectification link, its current transformer H encloses to secondary elementary 4 circles around 64 with enameled wire on the magnetic core of φ 12 * φ 6 * 5; Totally 3.Mutual inductor has two elementary windings among the figure, level induces in the winding secondarily be two elementary windings current phasor and.Be called vector superposed formula current transformer.This mutual inductor adds that three-phase bridge rectification has good open-phase protection ability; (2) level conversion link, the level signal that changes wide variation by the mutual inductor secondary signal of transistor exclusive disjunction amplifier after with rectification into is called level conversion.During with 12 volts of power supplys, transistor load resistance is got 13K, and to the tested electric current of 1～3 peace, the voltage of collector load resistor changes between 6～11 volts.For making the circuit operate as normal, pull-up resistor is wanted shnt capacitor C1.R2 and R3 are respectively that resistance is set in the control of warning and automatic switchover link, are used to set concrete Control current.(3) and (four) for automaticallying switch and the warning link, respectively with relevant ohmically voltage of setting and relay IJ1 or loudspeaker in the level conversion link as separately control signal and load; Fig. 2 is a power supply, and resistance R inserts for adapting to different resistance; Fig. 3 is the wiring diagram of general purpose controller TC, the elementary power lead that is serially connected with its AC motor JD that controls of the current transformer H of general purpose controller; This principle of work by the robot control system(RCS) that general purpose controller and motor are formed is: press the button A1 during startup, trigger C gets electric self-locking and connects motor and general purpose controller, and the R4C2 loop guarantees the motor normal starting.During machine operation; the ohmically voltage of level conversion transistor load reflects the working current of motor all the time; in case overload or phase shortage increase current of electric; detection ring is energy-conservation to be measured the signal of this electric current increase and is sent to the level conversion link; amplify and change into higher voltage signal on its pull-up resistor by transistor; this voltage signal is by variable resistor R2; deliver to after the R3 dividing potential drop and report to the police or automatic switchover link time base circuit reset terminal; when the automatic switchover time base circuit resets; relay normally closed contact IJ1 disconnects; trigger C outage makes the motor stall, reaches the purpose of protection.The resetting voltage that switches the link time base circuit can also be the preferential control signal introduced by terminals 2 as analog signalses such as the switching value that derives from scene or other control device or the light that passes through the detecting element input shown in frame of broken lines, displacement, pressure.In addition, the output signal of time base circuit output terminal also can be delivered to other place by terminals 1; R5 is as the positive feedback passage among Fig. 1, but the accelerating relay action.When normally opened contact IJ2 was subjected to other controlling unit (as Fig. 7,8 repeat circuit IJ2) control among Fig. 3, this system is Starting mode work automatically.At this moment R5 will use electric capacity generation among Fig. 1, and the power supply of general purpose controller TC should connect by dotted line among Fig. 3, and the startup of motor solves with the delay circuit that Fig. 9 provides.

Fig. 4 provided a kind of by the operational amplifier comparison mutual inductor H secondary current under the DC current I influence up and down the difference between the half-wave detect the mode of DC current.AC signal i can take from electrical network, and its fluctuation information can be with as shown in Figure 2 but secondary voltage is lower than the rectifier power source of integrated voltage stabilizer ratings all the time provides.Also can use ac generator; Detection signal is exported by resistance R.

Fig. 5 provides another embodiment of general purpose controller.The trigger end of time base circuit is directly introduced in the output of its mutual inductor H (also can not rectification) after rectification.The luminous warning of luminotron during overload.Single vector superposed formula current transformer also can be used for the overload and the open-phase protection of three-phase electrical equipment.

Fig. 6 is the value of the owing control embodiment of general purpose controller.Overload signal and carry out " line with " to realize control task separately independently through the value of owing (too small electric current) signal of the anti-phase amplification of triode.This line and mode also can be used for the same target control of the multiple signal of other form.

Fig. 7,8,9 provides general purpose controller " memory " link of three dual time base circuits respectively.Wherein be back time base circuit of being called of load with the switching device, another is called preceding time base circuit.Reach relevant capacitor charging/discharging approach their function as can be known from the level signal source of two time base circuit reset terminals, trigger end and thresholding end.The trigger end that the IJ2 of Fig. 7 gets electric need back time base circuit is that low level and reset terminal are that capacitor C 7 is high level, back one condition requires capacitor C 6 to be low level again, when capacitor C 6, C7 with load line 6(it with opertaing device simultaneously dead electricity) and frame 4, frame 5(they different charge and discharge time constants can be arranged) when being main charge and discharge approach, then load line gets electric of a specified duration more, the discharge required time is long more, thereby this circuit has last time the on time long more, starts just slow more control function automatically.Be applicable to the control of the equipment that requires interruption work.Frame 3 itself also has this function, but its cycle is shorter.To get the electric C5 of requirement be low level to IJ2 among Fig. 8, time base circuit was that low level is that capacitor C 6 is high level before this required, the main charging approach of C6 is a load line 6, the main loop of discharging is R6, charging and discharging circuit by C5 then, terminal point is the output terminal and the capacitor C 8 of preceding time base circuit, the preceding time base circuit of setting goes out low level capacitor C 5 and could be low level, then requiring C6 is high level, establish again load line 6 can quicken the charging process of C6 when electric, so it is long more that this circuit has on time last time, start fast more control function automatically.Can be used for the control of equipment such as the bigger air feed of duty cycle variation, feed flow.These two kinds of general purpose controller function links utilize its charge volume to estimate controlled physical quantity and need not to add in addition sensor with preceding joyous working time or this electric weight that be directly proportional stop time, that be connected to the capacitor of time base circuit trigger end or thresholding end of electrical equipment or its system.Fig. 9 is the time delay process of general purpose controller.It is the back time base circuit action of load that resetting in short-term of its preceding time base circuit do not made with the electronic switch.Be used to allow the control of the occasion of short-time overload.

Electric current when utilizing general purpose controller to observe the executive component action or other scale value and response time can be understood equipment working condition, and bonding apparatus service condition and loading condition setup control value and time constant can form various control systems. For example utilize the relation of electric current and moment of torsion, rotating speed, pressure and temperature to adopt special panel directly to control these physical quantitys.

But various general purpose controller described in the utility model has highly versatile, applied widely, the advantages such as control accuracy is high, the response time is short, high pressure isolation, operation and maintenance convenience, the little checkout equipment operating mode of volume, and its cost and maintenance and instructions for use are low more than computer control system.

Claims (3)

1, a kind of working current according to electrical equipment comes electronic installation that the operation of electrical equipment and system thereof is controlled, it comprises that by current transformer vector superposed formula current transformer, one or more control set the detecting element of resistance, sound and light alarm device, relay or electronic switch, control signal output display unit, preferential control signal or its input end, transistor, operational amplifier, time base circuit, power supply and scale panel and AC signal generator parts and form, and it is characterized in that:

A. the level conversion triode exclusive disjunction amplifier that contains its pull-up resistor shnt capacitor;

B. set the reset signal of the level signal of resistor dividing potential drop through control as time base circuit;

C. the output terminal of time base circuit and control are set between the resistance and are contained the positive feedback passage.

2, a kind of working current according to electrical equipment comes electronic installation that the operation of electrical equipment and system thereof is controlled, it is made up of sound and light alarm device, relay or electronic switch, power supply, current transformer parts, it is characterized in that: the signal of current transformer output directly or introduce the trigger end of time base circuit after the rectification.

3, electronic installation as claimed in claim 1 or 2 is characterized in that: contain last time working time of its charge volume and electrical equipment or its system or this stop time proportional capacitor that is connected to time base circuit trigger end or thresholding end.