CN201966795U

CN201966795U - Alternating current instant power down protection circuit for frequency conversion air conditioner

Info

Publication number: CN201966795U
Application number: CN201120014908XU
Authority: CN
Inventors: 袁双全
Original assignee: ZHUZHOU MEGMEET ELECTRICAL CO Ltd
Current assignee: ZHUZHOU MEGMEET ELECTRICAL CO Ltd
Priority date: 2011-01-17
Filing date: 2011-01-17
Publication date: 2011-09-07
Anticipated expiration: 2021-01-17

Abstract

The utility model provides an alternating current instant power down protection circuit for a frequency conversion air conditioner, which comprises a filter circuit, a rectification circuit, a power factor correcting circuit and an auxiliary power circuit which are connected in sequence, wherein the power factor correcting circuit is connected with the output end of a load; an electrolytic capacitor is connected in parallel onto both ends of the load, namely a thermistor and a relay; the auxiliary power circuit comprises a first resistor and a first capacitor, wherein one end of the first resistor is connected with the anode of the electrolytic capacitor; the other end of the first resistor is grounded through a second resistor; the first capacitor is connected in parallel onto both ends of the second resistor; and the midpoints of the first resistor and the second resistor are connected with the sixth pin of a detection voltage chip. In the alternating current instant power down protection circuit, on the basis of the traditional circuit, the charging or the power down of the large electrolytic capacitor is set to be a specific value by a large electrolytic capacitor voltage detection network, and through controlling the relay to be opened and closed, a positive temperature coefficient thermistor (PTC) is capable of playing a role in limiting the current, and thereby, the normal operation of a machine is maintained and an fortuitous accident is also prevented from happening.

Description

Convertible frequency air-conditioner exchanges the instant power-down protective circuit

Technical field

The utility model relates to the convertible frequency air-conditioner technical field, relates in particular to a kind of convertible frequency air-conditioner and exchanges the instant power-down protective circuit.

Background technology

At present, variable frequency air-conditioner controller generally adopts semistor (PTC) or negative tempperature coefficient thermistor (NTC) to be serially connected in the ac circuit, it is excessive to limit the surge current of connecting when exchanging, to prevent to damage the components and parts (such as bridge heap, fuse, PFC, rectifier diode, big electrochemical capacitor) in the circuit.

Physical circuit as shown in Figure 1, when convertible frequency air-conditioner connects interchange (perhaps because of the incoming call once more that has a power failure), alternating current is through common mode inductance FL1, FL2, PTC, bridge heap BG1, PFC inductance L 3, PFC rectifier diode D2, big electrochemical capacitor EC12 is charged, usually the appearance value of EC12 very big (because the power consumption of air-conditioning is the KW level) in convertible frequency air-conditioner, cause charging current very big, must carry out the damage that current limliting prevents element.PTC just plays a metering function at circuit, when EC12 is charged to can make accessory power supply work the time, relay K 1 electric closure be carried out short circuit with PTC, to provide big load current to compressor.

But, the shortcoming of this circuit is: can not set EC12 what are charged to, accessory power supply is just worked with closed K1, in advance closed if (just can work about the accessory power supply 40Vdc that has), (just upward voltage is very high for the also very big PTC of charging current this moment in the contact sparking in the time of will causing K1 closed, in other words PTC does not play good metering function), of long duration gently then K1 damage the machine cisco unity malfunction, the heavy then K1 initiation fire that catches fire.

And, when exchanging instant power-down, follow the very fast alternating current that comes again, because of the appearance value of EC12 very big, it is slow to cause after the power down voltage on the EC12 to descend, and can not determine that because of accessory power supply how much voltage on the EC12 drops to and just do not work again, and the accessory power supply that has all can also be worked to about 30Vdc, if just send a telegram here once more this moment, PTC is the effect that will not have current limliting of closure because of K1 so.

The utility model content

The purpose of this utility model is to provide a kind of convertible frequency air-conditioner to exchange the instant power-down protective circuit.

The utility model purpose is achieved through the following technical solutions.

A kind of convertible frequency air-conditioner exchanges the instant power-down protective circuit, comprise: the filter circuit of Xiang Lianing, rectification circuit, circuit of power factor correction and auxiliary power circuit successively, circuit of power factor correction connects load output, and electrochemical capacitor is connected in parallel on the load two ends, thermistor and relay;

Comprise first resistance in the described auxiliary power circuit, a termination electrochemical capacitor positive pole of first resistance, the other end is through second grounding through resistance; First electric capacity is connected in parallel on the two ends of second resistance; First resistance links to each other with the 6th pin that detects the voltage chip with the mid point of second resistance.

Described, described first resistance comprises at least one resistance that is in series composition.

Described, described auxiliary power circuit one tunnel connects circuit of power factor correction, and one the tunnel connects rectification circuit through relay.

Described, described relay switch pin is connected in parallel on the thermistor two ends, described thermistor one termination filter circuit, another termination rectification circuit.

Described, described thermistor is semistor or negative tempperature coefficient thermistor.

The utility model embodiment compared with prior art, beneficial effect is: the utility model is by on the basis of available circuit, big electrochemical capacitor voltage detecting network, can set a big electrochemical capacitor charging or power down to an occurrence, by opening of control relay with closed, make PTC can be very to play metering function, thereby keep the operate as normal of machine, also prevented the generation of contingency.

Description of drawings

Fig. 1 is existing convertible frequency air-conditioner power down protection circuit;

Fig. 2 is that the utility model convertible frequency air-conditioner exchanges the instant power-down protective circuit.

Embodiment

In order to make the purpose of this utility model, technical scheme and advantage clearer,, the utility model is further elaborated below in conjunction with drawings and Examples.Should be appreciated that specific embodiment described herein only in order to explanation the utility model, and be not used in qualification the utility model.

See also shown in Figure 2, exchanging input links to each other with load through EMI filter circuit, rectification circuit, PFC circuit of power factor correction, electrochemical capacitor EC12, auxiliary power circuit one tunnel links to each other with coil one end of relay K, and another road links to each other with load, electrochemical capacitor EC12 and rectification circuit respectively; The coil other end of relay K links to each other with rectification circuit, and one group of switch pin of relay is connected in parallel on the two ends of thermistor F2, and thermistor one tunnel links to each other with the EMI filter circuit, and another road links to each other with rectification circuit.

Wherein, thermistor F2 can be semistor or negative tempperature coefficient thermistor

In the auxiliary power circuit, after resistance R 17, resistance R 16, resistance R 14 are connected successively, the anode of a termination electrochemical capacitor EC12, the other end is through resistance R 1 ground connection; Capacitor C 1 is connected in parallel on resistance R 1 two ends, and resistance R 1 links to each other with the 6th pin that detects voltage chip IC 1 with the mid point of resistance R 14.

Basic principle of the present utility model is exactly the IC1 that increases R14, R16, R17, R1, C1 and select band Brownout (switching on and shutting down detection voltage) function for use on the basis of Fig. 1, thereby solves existing shortcoming.

Make a concrete analysis of as follows: when convertible frequency air-conditioner connects interchange (perhaps because of the incoming call once more that has a power failure), alternating current is through common mode inductance FL1, FL2, PTC, bridge heap BG1, PFC inductance L 3, PFC rectifier diode D2, big electrochemical capacitor EC12 is charged, by setting electrochemical capacitor EC12 charge/discharge to concrete numerical value, auxiliary power circuit drives the relay K action, makes PTC can play good metering function.

For example: 220Vac exchanges input, it is 220Vdc start (for convertible frequency air-conditioner just can be started shooting at 160Vac), 180Vdc shutdown that Vec12=220X1.414, Vec12:310Vdc can set Vec12, therefrom can obviously contrast, the utility model scheme can reach fine PTC metering function.

The above only is preferred embodiment of the present utility model; not in order to restriction the utility model; all any modifications of within spirit of the present utility model and principle, being done, be equal to and replace and improvement etc., all should be included within the protection range of the present utility model.

Claims

1. a convertible frequency air-conditioner exchanges the instant power-down protective circuit, comprise: the filter circuit of Xiang Lianing, rectification circuit, circuit of power factor correction and auxiliary power circuit successively, circuit of power factor correction connects load output, and electrochemical capacitor is connected in parallel on the load two ends, thermistor and relay;

It is characterized in that, comprise first resistance in the described auxiliary power circuit, a termination electrochemical capacitor positive pole of first resistance, the other end is through second grounding through resistance; First electric capacity is connected in parallel on the two ends of second resistance; First resistance links to each other with the 6th pin that detects the voltage chip with the mid point of second resistance.

2. convertible frequency air-conditioner as claimed in claim 1 exchanges the instant power-down protective circuit, it is characterized in that, described first resistance comprises at least one resistance that is in series composition.

3. convertible frequency air-conditioner as claimed in claim 1 exchanges the instant power-down protective circuit, it is characterized in that described auxiliary power circuit one tunnel connects circuit of power factor correction, and one the tunnel connects rectification circuit through relay.

4. convertible frequency air-conditioner as claimed in claim 3 exchanges the instant power-down protective circuit, it is characterized in that described relay switch pin is connected in parallel on the thermistor two ends, described thermistor one termination filter circuit, another termination rectification circuit.

5. exchange the instant power-down protective circuit as each described convertible frequency air-conditioner of claim 1 to 4, it is characterized in that described thermistor is semistor or negative tempperature coefficient thermistor.