JPS5912940B2 - temperature control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a temperature control device that gradually brings the on level of a thermo circuit closer to the off level and controls the temperature without increasing the number of times a cold source is turned on and off.

Conventionally, for example, in air conditioners, a so-called liquid expansion thermostat has been used to detect the temperature of the air-conditioned space and turn the compressor on and off.

In this method, the hysteresis of the thermostat is relatively wide and the response speed is relatively slow, so the temperature swing in the air-conditioned space is larger than the hysteresis of the thermostat9, and it is not necessarily satisfactory in terms of pleasure.

Particularly during cooling, although the temperature was sufficiently controlled, the humidity was insufficiently controlled, and it was difficult to feel satisfied with the cooling operation.

This is because when the compressor is running for cooling, both the temperature and humidity drop, and when the set temperature is reached, the compressor stops operating.

After this, the temperature rises relatively slowly, but the humidity rises faster than the temperature.

This has the disadvantage of causing an unpleasant humidity condition before the temperature reaches the compressor starting temperature1. To solve this problem, reducing the hysteresis reduces the fluctuation of the detected temperature, for example in the air-conditioned space. This has the drawback of causing the cooling heat source to be turned on and off excessively in response to temperature changes due to the opening and closing of doors and windows, shortening its lifespan.

The present invention eliminates the conventional drawbacks and gradually brings the on level that controls the hysteresis of the thermo circuit constituting the temperature control device closer to the off level, thereby extending the life of the cooling heat source without excessively increasing the number of times it is turned on and off. The purpose is to obtain a temperature control device.

The present invention will be explained based on the drawings.

FIG. 1 is a block diagram, in which 1 is a temperature detector that detects the temperature of the air-conditioned space, and 2 is a cold source 5 that responds to the output of temperature detector 1.
3 is the hysteresis of the sash circuit 2;
That is, a hysteresis control circuit is shown that controls the on level and off level according to the output of the thermo circuit 2.

FIG. 2 shows the specific circuit shown in FIG. 1, and the operation of the circuit will be explained with reference to the timing chart shown in FIG.

Note that FIG. 2 is for cooling. 1 is a thermistor as a temperature detector, and with two resistors in series, the voltage Vc of the power supply 6 is
The voltage VA divided by c+ corresponds to the air-conditioned space temperature θA.

vA is the positive input of comparator 2D, and the negative input of V is
N is Vcc when the cold heat source 5 is on.
This is the voltage V1 divided by B and 2C.

Vl corresponds to the air-conditioned space temperature θ1.

Before time t2, as shown in FIG. 3a, vA〉θ
1, the comparator 2D output VD is vA>
It's bi because it's vl.

In other words, it becomes as shown in Figure 3.

Since VD is NO, transistor 4 is connected via resistor 4A.
Current flows through B, transistor 4B turns on, and relay 4C
is turned on, power is supplied to the cold source 5 from the commercial power source via the terminals L1*L2, and the cold source 5 operates.

In other words, it is as shown in Fig. 3e.

On the other hand, the capacitor 3C is charged with the output vD of the comparator 2D through the resistor 3B and the diode 3A, and the voltage Vc of the capacitor 3C is the output voltage vD of the comparator 2D.
The battery is charged up to 100%, as shown in Figure 3C.

This voltage appears at the output of voltage follower 3F.

That is, a timer is configured by a diode 3A, a resistor 3B, a capacitor 3C, and a voltage follower 3F.

The output of this timer is a 3G resistor. 3H1 transistor 3
j, a resistor 3j1, and a transistor J3.

That is, the timer output voltage VC is resistor 3G. A voltage vC2 divided by 3H is applied to the base of the transistor 31.

However, due to the output voltage vD of the comparator 2D, a base current flows to the transistor 3 via the base resistor 3j, and the transistor 3k is turned on, so the transistor 3
The base voltage of j is approximately zero and the transistor 31 is reverse biased, so that the negative input (voltage) VN becomes the divided voltage v1 of the VCC.

At time t1, vA>θ1, and the output V of comparator 2D
D is reversed to low, as shown in Figure 3.

Transistor 4B is turned off, relay 40 is turned off, and cold source 5 is turned off.

Since the output vD of the comparator 2D becomes low, the transistor 3 is turned off, and the voltage VB3max' obtained by dividing the voltage vc of the capacitor 3C at time t1, that is, Vcmax by the resistors 3G and 3H, is applied to the base of the transistor 310, and the negative input The voltage vN is obtained by subtracting the VBE of the transistor 31 from V B 3m a
As shown in Figure d, the negative input voltage vN rises from Vl to V2.

Therefore, in order for the cold source 5 to turn on again, vA is v
2 equivalent temperature θ2.

On the other hand, the capacitor voltage VC decreases exponentially because of the resistor 3B.

That is, it can be expressed as vc=Vcmax-t/'r.

Here, T is the resistance value R3B of resistor 3B and capacitor 3C
This is the so-called time constant multiplied by the static capacitance C3o.

As a result, the base voltage VB3 of the transistor 3j becomes v
It decreases by B3=vB3maXe-t/8.

Therefore, vN is vN=VB3maXe″″t/T−V
It decreases with BE.

That is, after time t2, Vc becomes as shown in FIG. 3C, and VN becomes as shown in FIG. 3D.

The on level X-Y of vA for the thermo circuit 2 to issue the on signal again gradually approaches θ1 as shown in FIG. 3a.

When vA reaches the on-level point P at time t2, the comparator 2D output vD is inverted from low to by, the transistor 3k is turned on, and the off-level at which the thermocircuit 2 outputs an off signal again is as shown in FIG. 3a. becomes θ1.

Since VD becomes NO, capacitor 3C is rapidly charged through diode 3A, rises to VD, and instantaneously becomes Vc.
Reach max.

After t2, temperature control is performed by repeating the same operation as before t2.

The present invention changes the load voltage vN of the thermocircuit over time based on the above-mentioned configuration, in other words, brings the heon level closer to the off level gradually over time. Appropriate temperature control can be achieved because the cooling and heating sources are activated quickly before the temperature reaches an uncomfortable state.

Although the above description has been made for cooling purposes, changing this to heating purposes can be achieved by exchanging the positional relationship of thermistor 1 and resistor 2A in FIG.

The thermo circuit 2, the switch circuit 4, and the hysteresis control circuit 3 are not limited to the circuit shown in FIG. 2, but may be of other circuit types, such as a type mainly using digital signals.

According to the present invention, since the on level is gradually brought closer to the off level with the passage of time, it is possible to appropriately adjust the humidity, and the number of times the cold source is turned on and off is also reduced compared to the case where the hysteresis is simply reduced. This results in effects such as comfortable temperature control without excessively increasing temperature.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG. 2 is a block diagram of an embodiment of the present invention.
FIG. 3 shows an example of the specific circuit shown in the figure, and FIG. 3 shows a timing chart for explaining the operation of FIG. 2, respectively. DESCRIPTION OF SYMBOLS 1...Temperature detector, 2...Thermo circuit, 3...Steresis control circuit, 4...Switch circuit, 5...Cold heat source, 6...Power source, 2D...Comparator, 3F・
...Voltage follower, 3i, 3, 4B...Transistor, 2A, 2B, 2C, 3B, 3G, 3H, 3j
. 4A...Resistor, 3A...Diode, 3C...Capacitor, 4C...Relay, Ll*L2...Commercial power supply terminal.

Claims (1)

[Claims] 1 A temperature detector that detects the temperature of the air-conditioned space, a thermo circuit that outputs a signal to turn on and off the cold source according to the output of the temperature detector, and a switch circuit that turns on and off the cold source according to the output of the thermo circuit. , control the on level and off level of the thermo circuit according to the thermo circuit output f
A hysteresis control circuit is provided, and the hysteresis control circuit includes a hysteresis circuit that applies vissteresis to the thermocircuit according to an output of the thermocircuit, and an on-level that is applied by the hysteresis circuit in response to an off output of the thermocircuit. and a timer circuit that approaches an off level over time.