JPS58205035A - Blower speed controller for airconditioner - Google Patents

Abstract

PURPOSE:To prevent the revolution of a blower from fluctuating due to heated reactor, while reducing noise and saving energy by a method wherein a blower is controlled through the intermediary of a reactor circuit while a stop circuit provided with hysteresis effect is inserted thereinto. CONSTITUTION:When the resistance value of a room temperature thermistor 1 is small and the input potential into an amplifier 6 is low, the output from the amplifier 6 attains to high potential while inputting the set potential of maximum potential setting circuit 10 into A point of a comparison circuit 13, further to input the output potential from the comparison circuit 13 into a reactor circuit 14. Resultantly the reactor circuit 14 approaches to saturation operating a blower 15 at the maximum revolution. On the contrary when the resistance value of the thermistor 1 is increased, the reactor 14 becomes unsaturated making the blower 15 operate at the minimum revolution determined by the set potential of the minimum potential setting circuit 9. Moreover when the air temperature decreases down to the set temperature of a stop circuit 17, the circuit 17 is actuated to make a contact 18 stopping the blower 15. In such a constitution, the blower 15 may be relieved from the unfavorable effect of heated reactor while reducing noise and saving energy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a blower speed control device for an air conditioner.

Generally, a control device for an air conditioner needs to vary the rotational speed of an AC motor for a blower, which is a load, and methods using Zyristors and triacs have been widely known as methods for controlling this AC load. However, as shown in Figure 1, the load voltage waveform has large waveform distortion and also contains a large amount of high frequency components, which may cause vibrations of the motor, magnetic noise, electromagnetic noise, etc. .

The conventional solution to this problem was to make the case of the electric motor out of casting, but in recent years, due to the cost reduction and weight reduction of electric motors, the case has become more and more made out of sheet metal or plastic, and as a result, the case has been eliminated. There was the above-mentioned vibration, magnetic sound.

The drawback is that it tends to generate electromagnetic noise.

This invention was made to eliminate the above-mentioned drawbacks, and by using a new control means for controlling an AC load such as an AC motor, vibrations and magnetic noise can be reduced.

It is an object of the present invention to provide a blower speed control device for an air conditioner that can eliminate electromagnetic noise and save energy by controlling the rotation speed of the blower or stopping its operation based on the deviation between a predetermined environmental temperature and a set temperature. This is the purpose.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

2 and 3 are block diagrams and detailed circuit diagrams showing one embodiment of the present invention, and in FIG. 1, numeral 1 indicates a temperature sensor such as a thermistor for detecting room temperature.

2 a * 2 b + 2 c is a three-pole, double-throw changeover switch that switches between air conditioning and room 11, 3 is a DC power supply, and 1 is stabilized by a rectifier and smoothing circuit that rectifies and smoothes the AC power supply current (not shown), a Zener diode, etc. This was obtained by configuring the power supply. 4 is a variable resistor, which allows the customer to arbitrarily vary the set temperature. 5 is a semi-fixed resistor, and the thermistor 1
When the resistance value of , that is, the room temperature reaches the set temperature, the potential at the connection branch point between the thermistor 1 and this semi-fixed resistor 5 remains equal even if the changeover switch 2 is switched to cold and warm respectively. It is preset so that the voltages applied to the blowers are equal.

6 is an amplifier circuit whose output increases when the input potential decreases, and conversely, when the input potential increases, the output decreases.

7.8 is a diode, 9 is a minimum voltage setting circuit, and 10 is a maximum voltage setting circuit, which limit the anode side potential of the diode 7.8 to within the set minimum voltage and maximum voltage, respectively. 11. 12 is a resistor, 13 is a comparator circuit, and the potential at one input point A is higher than the potential of the minimum voltage setting circuit 9, lower than the potential of the maximum voltage setting circuit 10, and is connected to the thermistor 1. A potential corresponding to the detected indoor temperature is supplied. The reference voltage divided by the resistors 11 and 12 is supplied to the other input terminal of the comparator circuit 13, and this reference voltage is compared with the voltage at the point A, and an output potential corresponding to the potential at the point A is determined. Occur.

That is, if the potential at point A increases, the output also increases. 1
4 is a reactor circuit, which includes first saturable reactors 14b each having the same characteristics, and the control side windings are connected in series with one winding end side and the other winding start side; The load-side windings are connected by connecting one winding end and the other winding end, and each winding start side is connected in series to the blower 15 and the AC power supply 16, which are loads. In addition, the number of windings on the control side is several times larger than the number of windings on the load side, so that a small current change on the control side produces a large current change on the load side.

The reactors 14a and 14b are configured to cancel out the generated voltages with each other by the above-described load side winding connection method so as not to generate high voltage on the control side. 17 is a stop circuit that is equipped with an IC (not shown) and a relay inside, and when the input potential rises, the output potential of the IC rises and turns on the relay.
The normally closed contact 18 of this relay is connected in series to the reactor circuit 14, blower motor 15 and AC power source 16. Also, if the indoor temperature drops by a certain temperature from the set temperature during cooling, this stop circuit 17
The relay is set in advance to turn on, and the ON/OFF operating temperature of this relay is given a hysteresis effect.

Based on the above configuration, the operation of an embodiment of the present invention will be explained with reference to the drawings.

Now, considering cooling, when the indoor temperature is very high compared to the set temperature, the resistance value of the thermistor 1 is small and the input potential of the amplifier circuit 60 is also low. As a result, the output potential of the amplifier circuit 6 is high ( , the potential set by the highest potential setting circuit 10 is supplied to one input point A of the comparator circuit 13, and its output potential is given to the reactor circuit 14.Therefore, the reactors 14a and 14b approach the saturated state (because , the impedance on the load side decreases, the blower 15 rotates at the highest voltage, and the air conditioner is rapidly cooled.As the room temperature decreases, the potential detected by the thermistor l begins to rise, and the amplifier circuit 6 The potential supplied to the reactor circuit 14 via the comparator circuit 13 begins to decrease, and both the reactors 14a.

14b approaches a non-saturated state, the rotational speed of the blower 15 begins to decrease. When the indoor temperature eventually reaches the set temperature, the low potential set by the minimum voltage setting circuit 9 is supplied to the reactor circuit 14 via the comparison circuit 3, so that the blower 150 is operated at the minimum rotation speed. Furthermore, if the indoor temperature drops below the set temperature 1, for example, the stop circuit 1
When the temperature drops by an arbitrary amount set in step 7, a relay provided inside this stop circuit 17 is turned on.

The operation of the blower 15 is stopped by the operation of the normally closed contact 18. Thereafter, when the indoor temperature rises again by the amount of hysteresis set by the stop circuit 17, the blower 15 starts operating at the lowest voltage.

□ Repeat the same operation below. i In the case of heating, the connection of the thermistor 1 that detects the indoor temperature is changed by the changeover switch 2, so the minimum voltage, maximum voltage, stop temperature, hysteresis temperature width, etc. applied to the blower 15 are the same, but The voltage change characteristics of the blower 15 with respect to the indoor temperature are completely opposite. In addition, since the semi-fixed resistor 5 is set in advance so that the voltage applied to the blower 15 is the same even if the changeover switch 2 is changed when the indoor temperature reaches the set temperature (-), the voltage applied to the blower 15 is set in advance. The voltage change characteristics of the blower 15 as shown in FIG.

Furthermore, since the voltage waveform applied to the blower 15 uses a saturable reactor, the voltage waveform becomes as shown in FIG. It becomes a sine wave. - When the blower voltage is low, the waveform will contain some waveform distortion, but this is low-frequency waveform distortion and not the high-frequency waveform distortion that occurs when controlling with a conventional triac or thyristor. Vibration of the blower, generation of magnetic noise, electromagnetic noise, etc. are prevented. death·.

As explained above, the present invention implements control using a reactor in a blower control device for an air conditioner, and also provides a stop circuit having a hysteresis effect to automatically adjust the rotation speed of the blower according to a predetermined environmental temperature. By making it variable or stopping, it is possible to eliminate vibrations, magnetic noise, electromagnetic noise, etc. that were problems with conventional methods, and it is also possible to prevent changes in the rotation speed of the blower due to heat generated by the reactor, and at the same time, it reduces the use of wasted energy. This has the practical effect of saving energy without any effort.

[Brief explanation of the drawing]

FIG. 1 is a voltage waveform diagram showing the operation of a blower of a conventional air conditioner, FIG. 2 is a block diagram showing an embodiment of the present invention, and FIG. 3 is a detailed circuit diagram of FIG. 2. FIG. 4 is an operating characteristic diagram showing an embodiment of the present invention. FIG. 5 is a diagram corresponding to FIG. 1 showing an embodiment of the present invention. l...Thermistor 6...Amplifier circuit 9...Minimum voltage setting circuit 10...
・Maximum voltage setting circuit 13...Comparison circuit 14...Reactor circuit 15...Blower 17...Stop circuit Note that the same symbols in the diagram indicate the same parts. , or a corresponding portion. Agent Shin Kuzuno - (1 other person)

Claims (1)

[Claims] (1) A blower, a switching means for switching between cooling and heating, a first temperature control means for varying an arbitrary set temperature of a predetermined environment, and a first temperature control means for varying an arbitrary set temperature of a predetermined environment. , temperature detecting means for detecting the predetermined environmental temperature; and when the temperature detecting means detects the predetermined environmental temperature reaching the preset temperature set by the temperature control means, the temperature does not change even if the switching means is switched. The second electrode is set so that the potential at the connection point with the detection means does not change and becomes equal potential.
temperature control means, an amplifier circuit that inputs the potential of the connection point, a maximum voltage setting circuit connected to the output of the amplifier circuit that sets the maximum voltage, a minimum voltage setting circuit that sets the minimum voltage, a comparison circuit that compares the voltage of the amplifier circuit, which corresponds to the predetermined environmental temperature in the voltage range a between the voltage and the minimum voltage, with a preset reference voltage and outputs an output according to the deviation; - an output of the comparison circuit; and a stop circuit that operates with a predetermined hysteresis characteristic when the potential at the connection point rises, and the stop circuit is provided between the reactor circuit and the blower. Features: Air conditioner blower speed control device.