CN205753347U - Power load limiter - Google Patents

Abstract

The utility model discloses a kind of power load limiter, including power circuit, load detecting circuit, monostable circuit, on-off circuit and warning circuit；Civil power is converted into 12V DC voltage by power circuit, provides running voltage for monostable circuit, on-off circuit and warning circuit；Load detecting circuit detection load current, formation triggering level；Monostable circuit forms a switch controlling signal under the effect of triggering level；Switch controlling signal controls on-off circuit and disconnects or connecting subscribers participating load；Warning circuit is connected with on-off circuit.This utility model has automatic electric limiting and controls function, it is energy normal power supply when bearing power (electric power of user) is less than power limitation, when bearing power exceedes power limitation, the supply line of user can be cut off rapidly, overload user is given a warning simultaneously.

Description

Power load limiter

Technical field

This utility model relates to a kind of power load limiter, belongs to safety technique for using electricity field.

Background technology

Electric energy is a kind of clean energy resource, and modern society people have be unable to do without electricity, even the Linzhi that China is the remotest Area, within 2012, rural area current on time all reaches 100%.Along with the raising of people's living standard, household electrical appliance are more Coming the most, electric power is increasing.Particularly summer, one family refrigerator, kitchen range, air-conditioning, colour TV one Rising and use, electric power can increase suddenly, often asking due to the excessive unexpected appearance switch port-cullis protection of complexity Topic.The consequence caused is that all electrical equipments all cannot work, and there will be night and blackens the name of, and affects people's life.

Summary of the invention

This utility model purpose is to provide a kind of power load limiter, this limiter can according to the situation of setting, When user load is excessive, automatic disconnecting consumers power supply.

To achieve these goals, this utility model one power load limiter, including power circuit, load Testing circuit, switching value form circuit, on-off circuit and warning circuit；Civil power is converted into 12V by power circuit DC voltage, forms circuit, on-off circuit and warning circuit for switching value and provides running voltage；Load detecting electricity Road detection load current, form triggering level, this triggering level through switching value formed circuit become one stable Switch controlling signal；Switch controlling signal controls on-off circuit and disconnects or connecting subscribers participating load；Warning circuit with open Pass circuit is connected；

Described switching value forms circuit and includes NAND gate G1, NAND gate G2, NAND gate G3, NAND gate G4, electricity Resistance R2, resistance R3 and electric capacity C3；Triggering level connects two inputs of NAND gate G1；The output of not gate G1 Holding a road to connect an input of NAND gate G3, another road connects two inputs of NAND gate G2；NAND gate The output of G2 accesses two inputs of NAND gate G1 by resistance R2 feedback；The output of NAND gate G3 is passed through The input of NAND gate G4 is accessed after the filter circuit of electric capacity C3 and resistance R3 composition；The output of NAND gate G4 Access another input of not gate G3.

This utility model has automatic electric limiting and controls function, and it is less than in bearing power (electric power of user) During power limitation, energy normal power supply, when bearing power exceedes power limitation, can cut off rapidly the supply lines of user Road, gives a warning to overload user simultaneously.

Accompanying drawing explanation

Fig. 1 is this utility model theory diagram；

Fig. 2 is that this utility model switching value forms circuit theory diagrams；

Fig. 3 is this utility model power circuit principle figure；

Fig. 4 is this utility model load detecting circuit schematic diagram；

Fig. 5 is this utility model on-off circuit and warning circuit schematic diagram.

Detailed description of the invention

Below in conjunction with the accompanying drawings this utility model is described further.

As it is shown in figure 1, a kind of power load limiter, including power circuit, load detecting circuit, switching value Form circuit, on-off circuit and warning circuit；Civil power is converted into 12V DC voltage by power circuit, for switch Amount forms circuit, on-off circuit and warning circuit and provides running voltage；Load detecting circuit detection load current, Forming triggering level, this triggering level forms circuit through switching value and becomes a stable switch controlling signal；Open Close control signal and control on-off circuit disconnection or connecting subscribers participating load；Warning circuit is connected with on-off circuit；

As in figure 2 it is shown, described switching value formed circuit include NAND gate G1, NAND gate G2, NAND gate G3, NAND gate G4, resistance R2, resistance R3 and electric capacity C3；Triggering level connects two inputs of NAND gate G1； Outfan one tunnel of not gate G1 connects an input of NAND gate G3, and another road meets two of NAND gate G2 Input；The output of NAND gate G2 accesses two inputs of NAND gate G1 by resistance R2 feedback；With non- The output of door G3 is by accessing the input of NAND gate G4 after the filter circuit of electric capacity C3 and resistance R3 composition； The output of NAND gate G4 accesses another input of not gate G3.

This utility model has automatic electric limiting and controls function, and it is less than in bearing power (electric power of user) During power limitation, energy normal power supply, when bearing power exceedes power limitation, can cut off rapidly the supply lines of user Road, gives a warning to overload user simultaneously.

As it is shown on figure 3, described power circuit is by decompression capacitor C5, resistance R6, rectifier bridge stack UR, voltage stabilizing two Pole pipe VS and filter capacitor C4 composition；Electric capacity C5 and resistance R6 parallel connection form reduction voltage circuit, Zener diode VS and filter capacitor C4 parallel connection form filter circuit of pressure-stabilizing；Civil power is first by reduction voltage circuit blood pressure lowering, through rectifier bridge Heap UR direct current, then export after voltage regulation filtering.

As shown in Figure 4, described load detecting circuit includes current transformer, diode VD1, resistance R1, change Resistance device RP, electric capacity C1 and electric capacity C2, diode VD1, resistance R1 and rheostat RP are sequentially connected in series and are connected on electricity The second siding ring two ends of current transformer；Electric capacity C1 is in parallel with rheostat RP, rheostat RP and Current Mutual Inductance The second siding ring junction point of device connects signal ground by electric capacity C2.Current transformer, diode VD1, resistance R1 and rheostat RP forms a loop, the friendship that the second siding ring of current transformer is produced by diode VD1 Stream electric current is converted to DC current, under the filter action of electric capacity C1 and electric capacity C2, and the slip of rheostat RP Section output DC voltage, this DC voltage, as the triggering signal of monostable circuit, adjusts rheostat RP permissible Change output to set.

As it is shown in figure 5, described on-off circuit includes resistance R4, transistor switch V and relay switch K；Single The switch controlling signal of steady-state circuit output enters the base stage of transistor switch V through resistance R4；Transistor switch The colelctor electrode of V connects 12V DC voltage, and emitter stage is through the control termination signal ground of relay switch K；Relay The on and off switch that contact sets K1 is user load of device switch K, user load connects normally closed point.Work as user load When exceeding setting value, the switch controlling signal that monostable circuit is formed makes transistor switch V turn on, relay The normally closed disconnection of contact sets K1 of switch K, user load disconnects.

As it is shown in figure 5, described warning circuit includes generating resistance R5, luminous tube VL and alarm bell, luminous tube VL After connecting with resistance R5, the control end with relay switch K is in parallel；The contact sets of alarm bell contact relay switch K The normally opened point of K1.When user load exceedes setting value, the switch controlling signal that monostable circuit is formed makes Transistor switch V turns on, and the normally opened Guan Bi of contact sets K1 of relay switch K, alarm bell sounds the alarm Sound, luminous tube VL obtains electroluminescence.

Claims (5)

1. a power load limiter, it is characterised in that include power circuit, load detecting circuit, switching value Form circuit, on-off circuit and warning circuit；Civil power is converted into 12V DC voltage by power circuit, for switch Amount forms circuit, on-off circuit and warning circuit and provides running voltage；Load detecting circuit detection load current, Forming triggering level, this triggering level forms circuit through switching value and becomes a stable switch controlling signal；Open Close control signal and control on-off circuit disconnection or connecting subscribers participating load；Warning circuit is connected with on-off circuit；

Described switching value forms circuit and includes NAND gate G1, NAND gate G2, NAND gate G3, NAND gate G4, resistance R2, resistance R3 and electric capacity C3；Triggering level connects two inputs of NAND gate G1；The outfan of not gate G1 One tunnel connects an input of NAND gate G3, and another road connects two inputs of NAND gate G2；NAND gate The output of G2 accesses two inputs of NAND gate G1 by resistance R2 feedback；The output of NAND gate G3 is passed through The input of NAND gate G4 is accessed after the filter circuit of electric capacity C3 and resistance R3 composition；The output of NAND gate G4 Access another input of not gate G3.

Power load limiter the most according to claim 1, it is characterised in that described power circuit is by blood pressure lowering Electric capacity C5, resistance R6, rectifier bridge stack UR, Zener diode VS and filter capacitor C4 composition；Electric capacity C5 Form reduction voltage circuit, Zener diode VS and filter capacitor C4 parallel connection with resistance R6 parallel connection and form voltage regulation filtering Circuit；Civil power is first by reduction voltage circuit blood pressure lowering, through rectifier bridge stack UR direct current, then exports after voltage regulation filtering.

Power load limiter the most according to claim 2, it is characterised in that described load detecting circuit bag Include current transformer, diode VD1, resistance R1, rheostat RP, electric capacity C1 and electric capacity C2, diode VD1, resistance R1 and rheostat RP are sequentially connected in series the second siding ring two ends being connected on current transformer；Electric capacity C1 In parallel with rheostat RP, rheostat RP is connect by electric capacity C2 with the second siding ring junction point of current transformer Signal ground.

Power load limiter the most according to claim 3, it is characterised in that described on-off circuit includes electricity Resistance R4, transistor switch V and relay switch K；The switch controlling signal of monostable circuit output is through resistance R4 enters the base stage of transistor switch V；The colelctor electrode of transistor switch V connects 12V DC voltage, emitter stage Control termination signal ground through relay switch K；Contact sets K1 of relay switch K is user load On and off switch, user load connects normally closed point.

Power load limiter the most according to claim 4, it is characterised in that described warning circuit includes sending out Resistance R5, light pipe VL and alarm bell, light pipe VL connect with resistance R5 after with the control end of relay switch K also Connection；The normally opened point of contact sets K1 of alarm bell contact relay switch K.