A kind of charging circuit and convertible frequency air-conditioner with overvoltage crowbarTechnical field
The present invention relates to convertible frequency air-conditioner technical field, in particular to a kind of charging circuit with overvoltage crowbar.
Background technique
There are two types of specifications, respectively 110V and 220V for the input of convertible frequency air-conditioner AC power source.Under different voltages, convertible frequency air-conditioner masterPlate electronic component type selecting can not be identical.Compared with 220V, the pressure resistance of 110V electric supply system variable-frequency mainboard electrolytic capacitor is moreIt is low, cost is less expensive.Therefore the air-conditioning of 110V power supply system cannot be used under 220V Power Supplies Condition.And existing convertible frequency air-conditioner mainboardMost of no design overvoltage crowbars, thus appear in actual use, should connect the frequency conversion of 110V power supply originally220V power supply in air-conditioning quilt misconnection, so that each component receives damage in convertible frequency air-conditioner, more serious generation fire jeopardizes peopleMember and property safety.
Even if part Design of Variable Frequence Air Conditioner has overvoltage crowbar, but structure is complicated for most overvoltage crowbar, needsThe faster overvoltage protection response time is wanted, there are certain risks.
Summary of the invention
In view of this, the present invention is directed to propose a kind of charging circuit with overvoltage crowbar, is used to work as power supply power supplyThe power supply of system misconnection too high voltages makes, and protection charging current is not damaged.
In order to achieve the above objectives, the technical scheme of the present invention is realized as follows:
A kind of charging circuit with overvoltage crowbar, the charging circuit include AC power source, normally closed relay, mistakeVoltage protection circuit, rectifier bridge and electrolytic capacitor, the AC power source successively with normally closed relay, rectifier bridge and electrolytic capacitorConnection, the overvoltage crowbar is on the one hand in parallel with AC power source, on the other hand in parallel with normally closed relay.
Further, between the AC power source and rectifier bridge, PTC thermistor is connected in series.
Further, the normal off relay in parallel in the PTC thermistor.
Further, the overvoltage crowbar includes half-wave rectifying circuit and voltage regulator circuit, the half-wave rectifying circuitOn the one hand it connect, is on the other hand connect with voltage regulator circuit, the voltage regulator circuit is in parallel with the normally closed relay with AC power source.
Further, the overvoltage crowbar further includes voltage transformer, the primary coil of the voltage transformer withAC power source is in parallel, and the secondary coil of the voltage transformer is connect with half-wave rectifying circuit.
Further, the half-wave rectifying circuit includes diode and capacitor, on the secondary coil of the voltage transformerIt is sequentially connected in series diode and capacitor.
Further, the voltage regulator circuit includes power resistor and voltage-stabiliser tube, and the power resistor and voltage-stabiliser tube are connected shapeAt concatermer, the concatermer is in parallel with the capacitor, and the normally closed relay is connected in parallel on voltage-stabiliser tube.
Further, the half-wave rectifying circuit includes diode and capacitor, the voltage output end of the AC power source according toSecondary series diode and capacitor.
Further, the rectifier bridge includes first diode, the second diode, third diode and the four or two polePipe, the first diode are connected with the anode of the second diode, the cathode connection of a diode and the 4th diode, instituteThe cathode for stating the second diode is connect with the anode of third diode, the cathode of the third diode and the sun of the 4th diodePole connection.
A kind of convertible frequency air-conditioner, the convertible frequency air-conditioner include that aforementioned any frequency conversion with AC power source overvoltage crowbar is emptyAdjust charging circuit.
Compared with the existing technology, the convertible frequency air-conditioner charging circuit of the present invention with AC power source overvoltage crowbarIt has the advantage that
(1) the convertible frequency air-conditioner charging circuit of the present invention with AC power source overvoltage crowbar when power supply to supplyThe power supply of electric system misconnection too high voltages makes, and protection charging current is not damaged.
(2) the convertible frequency air-conditioner charging circuit configuration of the present invention with AC power source overvoltage crowbar is simplerIt is single.
A kind of convertible frequency air-conditioner, the convertible frequency air-conditioner include that aforementioned any frequency conversion with AC power source overvoltage crowbar is emptyAdjust charging circuit.
The convertible frequency air-conditioner and the above-mentioned convertible frequency air-conditioner charging circuit with AC power source overvoltage crowbar are relative to existingThere is advantage possessed by technology identical, details are not described herein.
Detailed description of the invention
The attached drawing for constituting a part of the invention is used to provide further understanding of the present invention, schematic reality of the inventionIt applies example and its explanation is used to explain the present invention, do not constitute improper limitations of the present invention.In the accompanying drawings:
Fig. 1 is a kind of charging circuit first structure diagram with overvoltage crowbar described in the embodiment of the present invention；
Fig. 2 is a kind of the second structural schematic diagram of charging circuit with overvoltage crowbar described in the embodiment of the present invention；
Fig. 3 is a kind of charging circuit third structural schematic diagram with overvoltage crowbar described in the embodiment of the present invention；
Fig. 4 is a kind of the 4th structural schematic diagram of charging circuit with overvoltage crowbar described in the embodiment of the present invention；
Fig. 5 is a kind of the 5th structural schematic diagram of charging circuit with overvoltage crowbar described in the embodiment of the present invention.
Description of symbols:
1- AC power source, 2- normally closed relay, 3- rectifier bridge, 31- first diode, the second diode of 32-, 33-Three diodes, the 4th diode of 34-, 4- electrolytic capacitor, 5-PTC thermistor, 6- normal off relay, 71- voltage transformer,72- diode, 73- capacitor, 74- power resistor, 75- voltage-stabiliser tube.
Specific embodiment
It should be noted that in the absence of conflict, the feature in embodiment and embodiment in the present invention can phaseMutually combination.
The present invention will be described in detail below with reference to the accompanying drawings and embodiments.
A kind of charging circuit with overvoltage crowbar, as shown in Figure 1, the charging circuit include AC power source 1, oftenClose relay 2, overvoltage crowbar, rectifier bridge 3 and electrolytic capacitor 4, the AC power source successively with normally closed relay 2, wholeGalvanic electricity bridge 3 and electrolytic capacitor 4 connect, and the overvoltage crowbar is on the one hand in parallel with AC power source 1, on the other hand with it is normally closed afterElectric appliance 2 is in parallel.Using such structure, the voltage in overvoltage crowbar perception AC power source can be made, and by AC power sourceOn alternating voltage be converted to firm DC voltage, driving normally closed relay 2 disconnects, and plays the role of protecting charging circuit.
Further, as shown in Fig. 2, between the AC power source 1 and rectifier bridge 3, PTC thermistor is connected in series5.Normally closed relay 2 is in normally off, i.e. PTC thermistor 5 is connected normally closed relay 2 with AC power source；The PTC heatQuick resistance 5 is connect as the voltage input end of AC power source with rectifier bridge 3, further, as shown in figure 3, in the PTC heatNormal off relay 6 in parallel on quick resistance 5；The rectifier bridge 3 according to rectifier bridge in prior art charging circuit connection sideFormula is connect with AC power source and electrolytic capacitor 4.The rectifier bridge 3 includes first diode 31, the second diode the 32, the 3rd 2Pole pipe 33 and the 4th diode 34, the first diode 31 are connected with the anode of the second diode 32, a diode 31It is connected with the cathode of the 4th diode 34, the cathode of second diode 32 is connect with the anode of third diode 33, describedThe cathode of third diode 33 is connect with the anode of the 4th diode 34.
When charging circuit works normally, the alternating voltage in AC power source is added to rectifier bridge 3 through PTC thermistor 5On, setting value is steadily charged to electrolytic capacitor 4, the power module (not shown) in parallel with electrolytic capacitor 4 is started to work,It is that three exchanges are electrically added on three phase alternating current motor winding by the DC voltage inversion that electrolytic capacitor 4 is input to power module, makesConvertible frequency air-conditioner motor runs well.After electrolytic capacitor 4 charges to setting value simultaneously, the DC voltage on rectifier bridge 3 is added to oftenOn disconnected relay 6, so that normal off relay 6 is closed, to make PTC thermistor 5 be short-circuited, to complete charging work.
On the one hand and friendship the overvoltage crowbar includes half-wave rectifying circuit and voltage regulator circuit, and the half-wave rectifying circuitThe connection of galvanic electricity source, on the other hand connect with voltage regulator circuit, the voltage regulator circuit is in parallel with the normally closed relay 2.
Further, as shown in figure 4, the overvoltage crowbar further includes voltage transformer 71, the voltage transformer71 primary coil is in parallel with AC power source, and the secondary coil of the voltage transformer 71 is connect with half-wave rectifying circuit.
Specifically, the half-wave rectifying circuit includes diode 72 and capacitor 73, the secondary line of the voltage transformer 71Diode 72 and capacitor 73 are sequentially connected in series on circle.
Further, voltage regulator circuit includes power resistor 74 and voltage-stabiliser tube 75, and power resistor 74 and voltage-stabiliser tube 75 are connected shapeAt concatermer, the concatermer is in parallel with capacitor 73, and normally closed relay 2 is connected in parallel on voltage-stabiliser tube 75, that is, forms the present inventionThe charging circuit with AC power source overvoltage crowbar.
A kind of charging circuit working principle with overvoltage crowbar of the present invention are as follows:
If the voltage of AC power source supply is more than scope of design, such as is originally designed to be the charging using 110V AC power sourceCircuit misconnection 220V AC power source, voltage transformer 71 incude the AC-input voltage size of AC power source, and exchange input is highVoltage is converted to exchange input low-voltage, and plays buffer action；The exchange that diode 72 converts mutual inductor inputs low electricityPressure halfwave rectifier is direct current, and capacitor 73 plays the role of the flat wave to the direct current of halfwave rectifier, and then obtains stable direct currentElectricity.Power resistor 74 and voltage-stabiliser tube 75 constitute voltage regulator circuit, obtain stable voltage between 75 cathode of voltage-stabiliser tube and anode.AndThe normally closed relay 2 on voltage-stabiliser tube 75 is associated under the action of DC voltage on voltage-stabiliser tube 75, it, i.e., will exchange into off-statePower supply and rectifier bridge 3 disconnect, and then avoid damage of the excessive alternating voltage to the subsequent component of charging circuit, to charging electricityRoad plays the role of overvoltage protection.
Further, as shown in figure 5, when the component for using voltage endurance capability strong and the normally closed relay for being able to bear high pressureWhen device 2, the voltage output end of the AC power source directly can be sequentially connected in series diode 72 and capacitor 73.
The present invention also provides a kind of convertible frequency air-conditioner, the convertible frequency air-conditioner includes aforementioned any described having AC power sourceThe convertible frequency air-conditioner charging circuit of overvoltage crowbar.
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, all in essence of the inventionWithin mind and principle, any modification, equivalent replacement, improvement and so on be should all be included in the protection scope of the present invention.