CN110212487A - A kind of overvoltage crowbar, method and air conditioner - Google Patents
A kind of overvoltage crowbar, method and air conditioner Download PDFInfo
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- CN110212487A CN110212487A CN201910474271.3A CN201910474271A CN110212487A CN 110212487 A CN110212487 A CN 110212487A CN 201910474271 A CN201910474271 A CN 201910474271A CN 110212487 A CN110212487 A CN 110212487A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/20—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess voltage
Abstract
The present invention provides a kind of overvoltage crowbar, method and air conditioner, and overvoltage crowbar includes: controllable switch device, and load circuit can pass through the controllable switch device and connect power supply；Control circuit connects the controllable switch device, and can be connected to the power supply；The control circuit when the voltage value of the power supply is less than the operating voltage of the load circuit, controls the controllable switch break-over of device, connects the load circuit and the power supply for sampling to the voltage of the power supply.
Description
Technical field
The present invention relates to air-conditioning technical fields, in particular to a kind of overvoltage crowbar, method and air conditioner.
Background technique
Electrical equipment has specified operating voltage, and the power supply that electrical equipment access matches with its operating voltage could just
Often work, if access and the unmatched power supply of its operating voltage, will lead to electrical equipment be can not work normally, or even can damage
Its internal components.For example, for the air conditioner for being applicable in single phase poaer supply, if being accessed three phase mains, due to three phase mains
Voltage 380V is much larger than the voltage 220V of single phase poaer supply, and electrolytic capacitor bulge failure will occur in the compressor drive circuit of air conditioner
Etc. device failures situation, cause unit to be unable to operate normally.
Summary of the invention
Problems solved by the invention is how to avoid damaging circuit devcie because of power supply over-voltage, and equipment is caused not transport normally
Row.
To solve the above problems, the present invention provides a kind of overvoltage crowbar, comprising:
Controllable switch device, load circuit can connect power supply by the controllable switch device；
Control circuit connects the controllable switch device, and can be connected to the power supply；
The control circuit for being sampled to the voltage of the power supply, when the voltage value of the power supply be less than it is described
When the operating voltage of load circuit, the controllable switch break-over of device is controlled, connects the load circuit and the power supply.
By above structure, control circuit can carry out detection to supply voltage value and carry out with the operating voltage of load circuit
Compare, when only supply voltage value is less than the operating voltage of load circuit, just by control controllable switch device, make power supply to
Load circuit power supply, can effectively avoid influences load circuit works because supply voltage value is much, prevents the device of load circuit
Excessive pressure damages improve the safety of load circuit.
In some embodiments of the invention, the control circuit includes:
Sample circuit can connect the power supply, and sample to the voltage of the power supply, obtain voltage sample value；
Comparison circuit connects the sample circuit, according to the voltage sample value judge the power supply voltage value whether
More than the operating voltage of the load circuit, if so, output enable signal；
Driving circuit connects the comparison circuit and the controllable switch device, makes in response to the enable signal
The controllable switch break-over of device.
In some embodiments of the invention, the power supply is AC power source, and the sample circuit includes:
Transformer, for the voltage of the power supply to be converted to secondary voltage；
Rectifier connects the transformer, and the secondary voltage is converted to direct current；
Divider connects the rectifier, divides to the direct current, using the partial pressure value of the direct current as institute
State voltage sample value；
The comparison circuit connects the divider, according to the turn ratio of the transformer, the rectification system of the rectifier
The voltage sample value is scaled the voltage value of the power supply by the intrinsic standoff ratio of several, the described divider.
In some embodiments of the invention, the output end parallel voltage-stabilizing capacitor of the rectifier.
By above structure, it is the charge-discharge characteristic using electric capacity of voltage regulation, stablizes the output voltage of rectifier, keep pulse straight
Galvanic electricity buckling is relatively steady dc voltage, brings adverse effect to subsequent device to avoid pulsating direct current.
In some embodiments of the invention, connect between the output end of the divider and the input terminal of the comparison circuit
Connect low-pass filter.
By above structure, the alternating component in direct current can be filtered out using low-pass filter, only retain DC component,
The quality for improving direct current, so that comparison circuit can work normally.
In some embodiments of the invention, the input terminal of the comparison circuit connects display device, when the voltage is adopted
When sample value is greater than the limiting value of the input terminal, the state of the display device changes.
By above structure, can be to being more than comparison circuit input terminal voltage limiting value the case where, prompting is played in time and is made
With.In some embodiments of the invention, the driving circuit includes: triode and DC power supply；
The base stage of the triode connects the output end of the comparison circuit, emitter ground connection, collector and the direct current
Power supply connects the controllable switch device；
When the base stage of the triode receives the enable signal, the triode ON makes the controllable switch
Break-over of device.
The present invention also provides a kind of over-voltage protection methods, comprising:
The voltage of power supply is sampled, voltage sample value is obtained；
According to the voltage sample value, judge the power supply voltage value whether be more than load circuit operating voltage, such as
Fruit is no, controls controllable switch break-over of device, connects the load circuit and the power supply.
By the above method, supply voltage value can be carried out to detect and be compared with the operating voltage of load circuit, only
When the operating voltage for thering is supply voltage value to be less than load circuit, so that power supply is powered to load circuit, can effectively avoid because of electricity
Source voltage value is much and influences load circuit works, prevents the device excessive pressure damages of load circuit, improves the safety of load circuit
Property.
In some embodiments of the invention, the voltage to power supply samples, the method for obtaining voltage sample value
Include:
The voltage of the power supply is converted to secondary voltage by transformer；
The secondary voltage is converted to direct current by rectifier；
Divider divides the direct current, using the partial pressure value of the direct current as the voltage sample value.
In some embodiments of the invention, described according to the voltage sample value, judge that the voltage value of the power supply is
The method of the no operating voltage more than load circuit includes:
Comparison circuit is according to the turn ratio of the transformer, the partial pressure of the rectification coefficient of the rectifier and the divider
Than the voltage sample value being scaled the voltage value of the power supply, and judge whether the voltage value of the power supply is more than load
The operating voltage of circuit.
In some embodiments of the invention, the voltage to power supply samples, the method for obtaining voltage sample value
Include:
Multiple repairing weld is carried out to the voltage of power supply, obtains multiple voltage sample values；
It is described according to the voltage sample value, judge the power supply voltage value whether be more than load circuit operating voltage
Include:
The average value according to multiple voltage sample values judges whether the voltage value of the power supply is more than load electricity
The operating voltage on road.
The accuracy of voltage sample value can be improved, obtain in such a way that multiple repairing weld is averaging by the above method
Supply voltage value it is more accurate and reliable.
The present invention also provides a kind of air conditioners, comprising: load circuit and overvoltage crowbar, the load circuit
Power supply is connected by the overvoltage crowbar.
In some embodiments of the invention, the load circuit is compressor drive circuit.
Detailed description of the invention
Fig. 1 is the structural schematic diagram of the overvoltage crowbar of the embodiment of the present invention.
Fig. 2 is the structural schematic diagram of the control circuit of the embodiment of the present invention.
Fig. 3 is the circuit diagram using circuit of the embodiment of the present invention.
Fig. 4 is the circuit diagram of the comparison circuit of the embodiment of the present invention.
Fig. 5 is the circuit diagram of the driving circuit of the embodiment of the present invention.
Fig. 6 is the partial circuit diagram of the air conditioner of the embodiment of the present invention.
Fig. 7 is the flow chart of the over-voltage protection method of the embodiment of the present invention.
Description of symbols:
T1- transformer；BG1, BG2- rectifier；E1, E6- electrolytic capacitor；E5- electric capacity of voltage regulation；R95, R96- divider resistance；
R97- filter resistance；C55- filter capacitor；D31, D-1- light emitting diode；In- input terminal；Out- output end；RY6- relay；
VCC- DC power supply；Q4- triode；R22- resistance；L1- inductance；Vad- voltage sample value；COM- enable signal；The end P3, P4-
Point；FILTER- low-pass filter；1- divider；2- display device.
Specific embodiment
To make the above purposes, features and advantages of the invention more obvious and understandable, with reference to the accompanying drawing to the present invention
Specific embodiment be described in detail.
One embodiment of the invention provides a kind of overvoltage crowbar, as shown in Figure 1, the overvoltage crowbar includes: can
Control switching device and control circuit.
Controllable switch device, load circuit can connect power supply by the controllable switch device.
Control circuit connects the controllable switch device, and can be connected to the power supply.
The control circuit for being sampled to the voltage of the power supply, when the voltage value of the power supply be less than it is described
When the operating voltage of load circuit, the controllable switch break-over of device is controlled, connects the load circuit and the power supply.
The overvoltage crowbar of the present embodiment is used to provide overvoltage protection for load circuit, specifically, according to power supply
Voltage condition, it is determined whether load circuit and power supply are connected.Load circuit does not power on not instead of directly, by controllable
Switching device connects power supply.Whether load circuit is connected with power supply is determined by the on off operating mode of controllable switch device.That is, when controllable
When switch device conductive, load circuit is just connected with power supply, and load circuit works on power；When controllably opening device disconnection, bear
It carries circuit and power supply is also to disconnect, load circuit no power.
In the present embodiment, control circuit includes: sample circuit, comparison circuit and driving circuit.
Sample circuit can be connected to power supply, and sample to the voltage of power supply, obtain voltage sample value.
Comparison circuit connects sample circuit, judges whether the voltage value of power supply is more than load circuit according to voltage sample value
Operating voltage, if comparison circuit judges the voltage value of power supply and is less than the operating voltage of load circuit, output one is enabled
Signal；If comparison circuit judges that the voltage value of power supply is more than the operating voltage of load circuit, enable signal is not exported.
Driving circuit connects comparison circuit and controllable switch device, controllable switch device is made in response to enable signal
Conducting.I.e. when comparison circuit exports enable signal, driving circuit receives the enable signal, and makes controllable switch break-over of device,
Load circuit and power supply are connected, and load circuit works on power；I.e. when comparison circuit does not export enable signal, driving circuit is not connect
The enable signal is received, then controllable switch device remains off, and load circuit is not connected with power supply, and load circuit is obstructed
Electricity.
The overvoltage crowbar of the present embodiment can be applied to any kind of electrical equipment, such as, but not limited to air-conditioning
The various household appliances such as device, refrigerator, washing machine, television set.Load circuit can be any kind of in these household appliances
Load circuit.In general, load circuit concrete form is related to the type of electrical equipment.For equipment such as air conditioner, refrigerators,
Compressor drive circuit is its main load circuit；For equipment such as washing machines, motor-drive circuit is its main load
Circuit；For television set, display panel, drive circuit is its main load circuit.Power supply for load circuit power supply can be
Any kind of power supply, such as alternating current and direct current etc..The voltage of power supply can be the voltage of any level.When power supply is alternating current
When, voltage can be 220V and 380V.
It is right for power supply is the alternating current of 220V below by taking load circuit is the compressor drive circuit of air conditioner as an example
The present embodiment is illustrated.It will be appreciated by those skilled in the art that described below be merely exemplary, do not constitute to the present invention
Limitation.
The overvoltage crowbar of the present embodiment, sample circuit are as shown in Figure 3, comprising: transformer T1, rectifier BG2, steady
Voltage capacitance E5, divider 1, low-pass filter FILTER.
The voltage of power supply is converted to secondary voltage using the voltage of power supply as primary voltage by transformer T1 connection power supply.
The voltage value of the secondary voltage depends on the turn ratio of the transformer T1.In one example, as shown in figure 3, working as power supply
When voltage Vac is 220V, the supply voltage of 220V is switched to the alternating current of 14.5V by transformer T1.
Rectifier BG2 connects the output end of transformer T1, secondary voltage is converted to direct current, by the voltage of direct current
Value is used as voltage sample value Vad.As shown in figure 3, in one example, the rectifier BG2 is bridge rectifier.Bridge rectifier
Device is made of four diodes, and input terminal connects the secondary end of transformer T1, the secondary voltage of receiving transformer T1, output
Hold exportable direct current.
Certainly above-mentioned only exemplary illustration, rectifier BG2 can use any kind of in addition to bridge rectifier
Rectifier.
The output end of the rectifier BG2 electric capacity of voltage regulation E5 in parallel.In Fig. 3, the electric capacity of voltage regulation E5 is electrolytic capacitor.
The direct current of rectifier BG2 output is Rectified alternating current, and it is filling using electric capacity of voltage regulation E5 that electric capacity of voltage regulation E5, which is arranged, in the present embodiment
Flash-over characteristic stablizes the output voltage of rectifier BG2, pulsed dc voltage is made to become relatively steady dc voltage, with
Pulsating direct current is avoided to bring adverse effect to subsequent device.
Divider 1 connects the output end of rectifier BG2, divides to direct current, using the partial pressure value of direct current as electricity
Press sampled value Vad.As shown in figure 3, divider 1 uses resistor voltage divider circuit, resistor voltage divider circuit includes concatenated two partial pressures
Resistance R95, R96.By selecting the resistance value of divider resistance R95, R96, suitable partial pressure value can be obtained, be suitable for partial pressure value
Input to comparison circuit, voltage sample value Vad made to be less than the limiting value of comparison circuit input terminal in, avoid the voltage of direct current with
The unmatched situation of comparison circuit occurs.
Certainly above-mentioned only exemplary illustration, divider 1 can be using any kind of points in addition to resitstance voltage divider
Depressor.
The output end of low-pass filter FILTER connection divider 1, that is, be connected between two divider resistances R95, R96.
As shown in figure 3, low-pass filter FILTER is RC filter, comprising: concatenated filter capacitor C55 and filter resistance R97.Filtering
The one end resistance R97 connects the output end of divider 1, and the other end connects one end of filter capacitor C55, and filter capacitor C55's is another
End ground connection.The effect of the RC filter is to carry out low-pass filtering to the direct current that divider 1 exports.Although rectifier BG2 is
Direct current is converted alternating current to, but the direct current obtained after rectifier BG2 rectification still has alternating component.Utilize low pass filtered
Wave device FILTER can filter out the alternating component in direct current, only retain DC component, the quality of direct current is improved, so as to compare
Circuit can work normally.
Certainly above-mentioned only exemplary illustration, low-pass filter FILTER can be using any classes in addition to RC filter
The low-pass filter of type.
Output end after the low-pass filtered device FILTER of the output end of divider 1 as sample circuit, as shown in figure 3, adopting
The output end of sample circuit is drawn between the filter resistance R97 and filter capacitor C55 of RC filter, connects the input of comparison circuit
In is held, Vad is to comparison circuit for output voltage sampled value.
In the present embodiment, in the output end of sample circuit, the input terminal in of namely comparison circuit, it is additionally provided with instruction electricity
Road.When the voltage sample value Vad of sample circuit output is more than the limiting value of comparison circuit input terminal in, the instruction electricity
The capable of emitting indication signal in road.Indicating circuit uses display device 2, as shown in figure 3, indicating circuit include: light emitting diode D31 with
And one 3.3V power supply.
The output end of the anode connection sample circuit of light emitting diode D31, that is, the input terminal in of comparison circuit, shine
The cathode of diode D31 connects the power supply of the 3.3V.3.3V, that is, comparison circuit input terminal in limiting value.
Although by the effect of rectifier BG2, divider 1, the voltage of power supply can be converted to appropriate voltage value to than
It is unstable compared with circuit, but due to supply voltage, there are still it is this may: i.e. the voltage of power supply by rectifier BG2 and divides
After depressor 1, obtained voltage value is still greater than the limiting value of comparison circuit input terminal in.Usual situation, light emitting diode D31 is just
The voltage of pole is less than the voltage of cathode, and light emitting diode D31 does not work.When voltage value, the i.e. comparison circuit using circuit output
When input voltage is greater than the limiting value of comparison circuit input terminal in, the voltage of light emitting diode D31 anode is greater than more electric at this time
The limiting value of road input terminal in, limiting value of the voltage equal to comparison circuit input terminal in of light emitting diode D31 cathode, luminous two
Pole pipe D31 conducting shines, and illustrates abnormal conditions occurred, can play in time reminding effect to abnormal conditions.
Certainly above-mentioned only exemplary illustration, indicating circuit can be using any type in addition to light emitting diode D31
Indicating circuit.
The overvoltage crowbar of the present embodiment, comparison circuit is as shown in figure 4, comparison circuit uses controller chip.Control
The output end of the input terminal connection sample circuit of device chip processed, the output end of controller chip connect driving circuit.
In the present embodiment, controller chip receives the voltage sample value Vad that sample circuit is sent, and according to the transformer
Voltage sample value Vad is scaled the voltage value of power supply by the intrinsic standoff ratio of the turn ratio of T1 and the divider 1.
Come back to Fig. 3, the sampling process of the overvoltage crowbar of the present embodiment are as follows: transformer T1 becomes supply voltage
Secondary voltage is converted to DC voltage by secondary voltage, rectifier BG2, and partial pressure value of the DC voltage after divider 1 is as electricity
Press sampled value Vad.
Therefore, in order to judge voltage source whether be more than load circuit operating voltage, it is necessary to first to obtain supply voltage
Value.After controller chip receives the voltage sample value Vad of sample circuit transmission, according to above-mentioned sampling process, by voltage sample
Value Vad counter can release supply voltage value.
In the present embodiment, the turn ratio of transformer T1 is k, and the rectification coefficient of rectifier BG2 is r, the intrinsic standoff ratio of divider 1
For d, then the relationship of supply voltage value and voltage sample value Vad is shown below:
Wherein, Vac is supply voltage value, and Vad is voltage adopted value.
Available, the supply voltage value by formula (1) are as follows:
For bridge rectifier BG2 shown in Fig. 3, commutation system isFor resistor voltage divider circuit, grouping electricity
The limiting value that the resistance value on road makes voltage sample value Vad be no more than comparison circuit input terminal in.
The controller chip of the present embodiment receives the voltage sample value Vad that sample circuit is sent, according to formula (2)
Voltage sample value Vad is scaled supply voltage value.
After obtaining supply voltage value, controller chip compares the operating voltage of supply voltage value and load circuit.This implementation
In example, the operating voltage of load circuit is 220V.Supply voltage value is compared by controller chip with 220V.If power supply is electric
Pressure value is not above 220V, illustrates that load circuit has accessed the power supply of 220V, can work normally, then exports an enable signal
COM；If supply voltage value has been more than 220V, such as supply voltage value has reached 380V, then illustrates load circuit misconnection
Three phase mains, the load circuit cisco unity malfunction under three phase mains, then do not export enable signal COM.
In the present embodiment, sample circuit can repeatedly be sampled the voltage of power supply, obtain multiple voltage sample value Vad.
Controller chip is averaging multiple voltage sample value Vad, and the average value of multiple power supply sampled values is substituted into formula (2) and is conversed
Supply voltage value.In such a way that multiple repairing weld is averaging, the accuracy of voltage sample value can be improved, obtained supply voltage
It is worth more accurate and reliable.Sampling period generally may be configured as 2s~30s.
Comparison circuit is illustrated by taking controller chip as an example above, the type of controller chip is not construed as limiting, example
It such as can be single-chip microcontroller, ASIC, CPLD, DSP, FPGA chip.Comparison circuit can also using it is any have input, calculate and
The circuit of output function, for example, the circuit of discrete component composition.
The overvoltage crowbar of the present embodiment, controllable switch device use relay RY6.Driving circuit connects relay
The coil of RY6, two endpoints P3, P4 of relay RY6 are separately connected load circuit and power supply.It is electric that driving circuit receives comparison
After the enable signal COM that road is sent, the coil of relay RY6 is made to be powered, two endpoints P3, P4 closure of relay RY6 makes to bear
It carries circuit and power supply is connected.
As shown in figure 5, load circuit by power supply line connect power supply, relay RY6 connection on the power line, the power supply line
It can be firewire or zero curve, two contacts of relay RY6 are separately connected power supply and load circuit, and relay RY6, which is in, to be disconnected
State.
Driving circuit includes: triode Q4, DC power supply VCC, light emitting diode D-1 and resistance R22.
The base stage of triode Q4 passes through the output end Out of resistance R22 connection comparison circuit, emitter ground connection, current collection
Pole connects one end of relay RY6 coil, the other end of DC power supply VCC connection relay RY6 coil.Light emitting diode D-1
It is connected in parallel between DC power supply VCC and the collector of triode Q4.The resistance value of the resistance R22 is 100 Ω~10K Ω.
When driving circuit is not received by enable signal COM, the base stage of triode Q4 is low level, and triode Q4 is closed
Disconnected, the emitter and collector of triode Q4 is not turned on, the coil no power of relay RY6, two endpoints of relay RY6
P3, P4 are disconnected, and load circuit is not connected with power supply, load circuit no power.When driving circuit receives enable signal COM,
The base stage of triode Q4 is high level, and triode Q4 is connected, and DC power supply VCC generates electric current, relay in relay RY6 coil
The coil of device RY6 is powered, and two endpoints P3, P4 closure of relay RY6, load circuit and power supply are connected, and load circuit powers on
Work.
It can be seen that the overvoltage crowbar of the present embodiment, control circuit supply voltage value can be carried out detection and with it is negative
The operating voltage for carrying circuit is compared, and when only supply voltage value is less than the operating voltage of load circuit, just passes through control
Controllable switch device makes power supply power to load circuit, and can effectively avoid influences load circuit work because supply voltage value is much
Make, prevents the device excessive pressure damages of load circuit, improve the safety of load circuit.
The above only exemplary illustration, the overvoltage crowbar of the present embodiment, in the case where guaranteeing to work normally, part
Device can be omitted.For example, electric capacity of voltage regulation E5, low-pass filter circuit, indicating circuit etc..
Another embodiment of the present invention provides a kind of over-voltage protection methods, and the over-voltage protection method is using above-described embodiment
Overvoltage crowbar provides overvoltage protection to load circuit.As shown in fig. 7, the over-voltage protection method includes:
Step S701: sampling the voltage of power supply, obtains the voltage sample value Vad.
Step S702: according to the voltage sample value Vad, judge whether the voltage value of the power supply is more than load circuit
Operating voltage, if not, control controllable switch break-over of device, connects the load circuit and the power supply.
In step s 701, the voltage of the power supply is converted to secondary voltage by transformer T1；Rectifier BG2 is by described time
Step voltage is converted to direct current；Divider 1 divides the direct current, using the partial pressure value of the direct current as the electricity
Press sampled value Vad.
In step S702, comparison circuit, will according to the turn ratio of the transformer T1 and the intrinsic standoff ratio of the divider 1
The voltage sample value Vad is scaled the voltage value of the power supply, and judges whether the voltage value of the power supply is more than load electricity
The operating voltage on road.
It can be seen that the over-voltage protection method of the present embodiment, the work detected and with load circuit is carried out to supply voltage value
It is compared as voltage, when only supply voltage value is less than the operating voltage of load circuit, just connects power supply with load circuit
Logical, power supply is powered to load circuit, and can effectively avoid influences load circuit works because supply voltage value is much, prevents load electricity
The device excessive pressure damages on road, improve the safety of load circuit.
In the present embodiment, step S701 can carry out multiple repairing weld to the voltage of power supply, obtain multiple voltage samples
Value Vad；Step S702 averages to multiple voltage sample value Vad, according to the average value of multiple voltage sample value Vad, judges institute
State power supply voltage value whether be more than load circuit operating voltage.
In such a way that multiple repairing weld is averaging, the accuracy of voltage sample value can be improved, obtained supply voltage value
It is more accurate and reliable.The sampling period for carrying out multiple repairing weld to supply voltage generally may be configured as 2s~30s, such as 5s.
The over-voltage protection method of the present embodiment, before step S701 further include: after overvoltage crowbar powers on, control electricity
Road exports reset first.For the overvoltage crowbar using controller chip, i.e. controller chip output resets.It in this way can be with
It prevents load circuit from having biggish voltage fluctuation, improves the accuracy of voltage sample value.
Another embodiment of the present invention provides a kind of air conditioner, air conditioner include: compressor, compressor drive circuit, with
And overvoltage crowbar.The overvoltage crowbar is using overvoltage crowbar described in above-described embodiment.
As shown in fig. 6, compressor drive circuit for driving compressor operating, is handed over by relay RY1 connection 220V
Galvanic electricity source.Compressor drive circuit includes rectifier BG1, inductance L1 and electrolytic capacitor E1, E6 etc..In the present embodiment, control
Circuit can carry out AC power source to detect and be compared with the operating voltage of compressor drive circuit, and only supply voltage value is not
More than load circuit operating voltage when, relay RY6 closure, power supply to compressor drive circuit power.Work as supply voltage value
More than load circuit operating voltage when, such as misconnection 380V three phase mains when, relay RY6 disconnect, driven compressor electricity
Road will not be connected with power supply.Can effectively avoid influences load circuit works because supply voltage value is much, prevents driven compressor
Device (such as electrolytic capacitor) excessive pressure damages of the circuit, improve the safety of compressor drive circuit.
Although present disclosure is as above, present invention is not limited to this.Anyone skilled in the art are not departing from this
It in the spirit and scope of invention, can make various changes or modifications, therefore protection scope of the present invention should be with claim institute
Subject to the range of restriction.
Claims (13)
1. a kind of overvoltage crowbar characterized by comprising
Controllable switch device, load circuit can connect power supply by the controllable switch device；
Control circuit connects the controllable switch device, and can be connected to the power supply；
The control circuit is for sampling the voltage of the power supply, when the voltage value of the power supply is less than the load
When the operating voltage of circuit, the controllable switch break-over of device is controlled, connects the load circuit and the power supply.
2. overvoltage crowbar as described in claim 1, which is characterized in that the control circuit includes:
Sample circuit can connect the power supply, and sample to the voltage of the power supply, obtain voltage sample value (Vad)；
Comparison circuit connects the sample circuit, according to the voltage sample value (Vad) judge the power supply voltage value whether
More than the operating voltage of the load circuit, if so, output enable signal (COM)；
Driving circuit connects the comparison circuit and the controllable switch device, makes in response to the enable signal (COM)
The controllable switch break-over of device.
3. overvoltage crowbar as claimed in claim 2, which is characterized in that the power supply is AC power source, the sampling electricity
Road includes:
Transformer (T1), for the voltage of the power supply to be converted to secondary voltage；
Rectifier (BG2), connects the transformer (T1), and the secondary voltage is converted to direct current；
Divider (1) connects the rectifier (BG2), divides to the direct current, and the partial pressure value of the direct current is made
For the voltage sample value (Vad)；
The comparison circuit connects the divider (1), according to the turn ratio of the transformer (T1), the rectifier (BG2)
Rectification coefficient, the divider (1) intrinsic standoff ratio, the voltage sample value (Vad) is scaled to the voltage value of the power supply.
4. overvoltage crowbar as claimed in claim 3, which is characterized in that the output end of the rectifier (BG2) is in parallel steady
Voltage capacitance (E5).
5. overvoltage crowbar as claimed in claim 3, which is characterized in that the output end and the ratio of the divider (1)
Low-pass filter (FILTER) is connected compared between the input terminal (in) of circuit.
6. overvoltage crowbar as claimed in claim 3, which is characterized in that input terminal (in) connection of the comparison circuit is aobvious
Show device (2), when the voltage sample value (Vad) is greater than the limiting value of the input terminal (in), the display device (2)
State changes.
7. overvoltage crowbar as claimed in claim 2, which is characterized in that the driving circuit include: triode (Q4) and
DC power supply (VCC)；
The base stage of the triode (Q4) connects the output end (Out) of the comparison circuit, emitter ground connection, collector and described
DC power supply connects the controllable switch device；
When the base stage of the triode (Q4) receives the enable signal (COM), triode (COM) conducting makes institute
State controllable switch break-over of device.
8. a kind of over-voltage protection method characterized by comprising
The voltage of power supply is sampled, voltage sample value (Vac) is obtained；
According to the voltage sample value (Vac), judge the power supply voltage value whether be more than load circuit operating voltage, such as
Fruit is no, controls controllable switch break-over of device, connects the load circuit and the power supply.
9. over-voltage protection method as claimed in claim 8, which is characterized in that the voltage to power supply samples, and obtains
The method of voltage sample value (Vac) includes:
The voltage of the power supply is converted to secondary voltage by transformer (T1)；
The secondary voltage is converted to direct current by rectifier (BG2)；
Divider (1) divides the direct current, using the partial pressure value of the direct current as the voltage sample value
(Vac)。
10. over-voltage protection method as claimed in claim 9, which is characterized in that it is described according to the voltage sample value (Vac),
Whether the voltage value for judging the power supply is more than that the method for operating voltage of load circuit includes:
Comparison circuit is according to the turn ratio of the transformer (T1), the rectification coefficient and the divider of the rectifier (BG2)
(1) the voltage sample value (Vac) is scaled the voltage value of the power supply, and judges the voltage of the power supply by intrinsic standoff ratio
Value whether be more than load circuit operating voltage.
11. over-voltage protection method as claimed in claim 8, which is characterized in that the voltage to power supply samples, and obtains
The method of voltage sample value (Vac) includes:
Multiple repairing weld is carried out to the voltage of power supply, obtains multiple voltage sample values (Vac)；
It is described according to the voltage sample value (Vac), judge the power supply voltage value whether be more than load circuit work electricity
Pressure includes:
The average value according to multiple voltage sample values (Vac) judges whether the voltage value of the power supply is more than load
The operating voltage of circuit.
12. a kind of air conditioner characterized by comprising load circuit and the described in any item over-voltages of claim 1 to 7 are protected
Protection circuit, the load circuit connect power supply by the overvoltage crowbar.
13. air conditioner as claimed in claim 12, which is characterized in that the load circuit is compressor drive circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910474271.3A CN110212487A (en) | 2019-05-31 | 2019-05-31 | A kind of overvoltage crowbar, method and air conditioner |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910474271.3A CN110212487A (en) | 2019-05-31 | 2019-05-31 | A kind of overvoltage crowbar, method and air conditioner |
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| CN110212487A true CN110212487A (en) | 2019-09-06 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201910474271.3A Pending CN110212487A (en) | 2019-05-31 | 2019-05-31 | A kind of overvoltage crowbar, method and air conditioner |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111668807A (en) * | 2020-05-07 | 2020-09-15 | 武汉市蓝电电子股份有限公司 | Overvoltage protection circuit for output port of battery test equipment |
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2019
- 2019-05-31 CN CN201910474271.3A patent/CN110212487A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111668807A (en) * | 2020-05-07 | 2020-09-15 | 武汉市蓝电电子股份有限公司 | Overvoltage protection circuit for output port of battery test equipment |
| CN111668807B (en) * | 2020-05-07 | 2022-07-01 | 武汉市蓝电电子股份有限公司 | Overvoltage protection circuit for output port of battery test equipment |
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