JPS63139224A - Temperature detector - Google Patents

Abstract

PURPOSE:To enhance the operational reliability of a blower, by stopping the operation of the blower when a temp. detector becomes an open or short-circuit state. CONSTITUTION:When a temp. detector 10 is in an open state by the disconnection of the lead wire of said detector, the converting voltage from a voltage converting apparatus 11 is applied to the negative side input of an open state detection comparator 17. An L-level signal is outputted from the output terminal 18 of the comparator 17 to be read in a microcomputer 14 which in turn judges an open zone to output a signal to control machinery 15 to stop a blower. Next, when the lead wire is in a short-circuit state, the converting voltage from the apparatus 11 is applied to the positive side input of a short-circuit state detection comparator 19. Then, an L-level signal is outputted from the output terminal 20 of the comparator 19 to be read in the microcomputer 14 which in turn judges a short-circuit zone to output a signal to the control machinery 15 to stop the blower. Since an A/D converter 13 and an apparatus 16 are provided to the output terminal of the apparatus 11 to perform the stoppage of the operation of the blower in both of the open zone and the short- circuit zone, the blower can be operated with high reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an air conditioner using a temperature sensor.
The present invention relates to a temperature detection device that detects an abnormality in a temperature detector.

Conventional technology Conventionally, all internal units of air conditioners are equipped with a heat exchanger that acts as an evaporator during cooling and as a condenser during heating.
This heat exchanger is equipped with a temperature sensor (thermistor), and this temperature sensor controls the indoor circulation fan to operate at low speed when the temperature exceeds a predetermined temperature, or to operate at high speed when the temperature falls below a certain level. . That is, as shown in FIG. 3, a voltage converter 2 having a temperature detector 1 for detecting the temperature of the heat exchanger is provided, and the temperature detected by the voltage converter 2 is converted into an analog value voltage, and the A/D converter converts the temperature detected by the voltage converter 2 into an analog value voltage. Output to converter 3. The A/D converter 3 converts the analog value into a digital value, which is read into the microcomputer 4. The microcomputer 4 converts the digital value into temperature and outputs it to the control device 6 to control the air volume of the blower.

Problems to be Solved by the Invention In such a conventional Hinoki construction, even when the temperature detector 1 incorporated in the voltage converter 2 is shut down or opened, the voltage is not output through the A/D converter 3. The microcomputer 4 detects the temperature and outputs it to the control device 6, so the blower is operated with either strong or weak winds fixed, and the actual temperature is not detected by the temperature detector 1, making it reliable. There was a problem in that the blower was operated in an unnatural manner.

The present invention solves these problems, and aims to provide a temperature detection device that stops the operation of the blower when the temperature detector becomes open or short-circuited, and allows the blower to operate with high reliability. shall be.

Means for Solving the Problem In order to solve this problem, the present invention provides a voltage converter having a temperature detector, an A/D converter connected to the output of the voltage converter, and a voltage converter having a temperature detector. a zone discriminator in parallel with the converter for determining when the temperature detector is open or short-circuited; a microcomputer connected to the output of the A/D converter and the output of the zone discriminator; It is equipped with connected control equipment.

With this configuration, when the temperature sensor becomes open or short-circuited, it is output to the voltage converter and the zone discriminator, and it is determined whether it is an open detection comparator or a short detection comparator, and is read by the microcomputer and output to the control equipment. If the condition is normal, the information is read into the A/D converter and microcomputer and the blower is operated normally.

EXAMPLE An example of the present invention will be described below with reference to FIGS. 1 and 2. As shown in the figure, a voltage converter 11 is provided which is connected to a temperature detector (thermistor) 10 attached to the heat exchanger of the indoor unit, and this voltage converter 11 detects the temperature of the heat exchanger and converts it into an analog value. The converted voltage is output from the output terminal 12 to the A/D converter 13.

The A/D converter 13 converts the analog value into a digital value, outputs it to the microcomputer 14, reads it into the microcomputer 14, converts the digital value into a temperature, outputs it to the control device 16, and operates the blower. .

That is, the engine is operated in a strong wind or weak wind operation zone with respect to a predetermined set temperature A shown in FIG. If the lead wire of the thermistor, which is the temperature detector 1o, is disconnected, it is in an open state, so the voltage is applied from the voltage converter 11 to the negative input of the open detection comparator 17 of the zone discrimination device ff1L1e via the output terminal 12. A shim level signal is output from the output terminal 18 and read into the microcomputer 14, which determines that it is an open zone as shown in FIG. 2, and outputs it to the control device 16 to stop the blower.

Next, if the lead wires are short-circuited, it is a short-circuit condition.
is applied to the positive side input of , an L level signal is output from the output terminal 20, and is read into the microcomputer 14,
It is determined that the short zone shown in FIG. 2 exists, and an output is sent to the control device 16 to stop the blower.

That is, when the temperature detector 1o is normally connected to the voltage converter 11, it is read by the microcomputer 14 via the A/D converter 13 and is operated in the operating zone shown in FIG. However, if the temperature sensor 10 is connected in an abnormal state, that is, if the lead wire of the thermistor is disconnected or short-circuited, the temperature sensor 10 is read by the microcomputer 14 via the zone discriminator 16, and the control equipment 16 is output and the blower is stopped. That is, in the past, the blower was operated in the open zone and the short zone, but in this embodiment, the zone discriminating device 1e stops the blower in the open zone and the short zone.

Effects of the Invention As is clear from the description of the embodiments described above, the present invention provides an A/D converter at the output end of a voltage converter having a temperature detector, and a zone discriminator in parallel with the A/D converter. Since the blower is set to stop operation in the open zone and short zone, the blower operates with high reliability and does not waste electricity. It is something.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a temperature detection device according to an embodiment of the present invention, FIG. 2 is an operating zone diagram of the same temperature detection device, and FIG. 3 is a circuit diagram of a conventional temperature detection device. 10... Temperature detector, 11... Voltage converter, 13... A/D converter, 14...
... Microcomputer, 16 ... Control equipment, 16 ... Zone discrimination device. Name of agent: Patent attorney Toshio Nakao and 1 other person
1 figure

Claims (1)

[Claims] A voltage converter having a temperature detector, an A/D converter connected to the output of the voltage converter, and a zone determination device in parallel with the A/D converter to determine when the temperature detector is open or short-circuited. a device;
A temperature detection device comprising a microcomputer connected to the output of the /D converter and the output of the zone discrimination device, and a control device connected to the output of the microcomputer.