CN2529255Y

CN2529255Y - Temp, humidity investigating instrument

Info

Publication number: CN2529255Y
Application number: CN 01228483
Authority: CN
Inventors: 吴燮华; 吴建德
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2001-07-09
Filing date: 2001-07-09
Publication date: 2003-01-01
Anticipated expiration: 2011-07-09

Abstract

The utility model relates to a temperature, humidity investigating instrument, which comprises a SCM, a temperature sensor, a humidity sensor, a humidity switch circuit and a liquid crystal display. The output end of the temperature sensor is connected with the SCM, and output of the humidity sensor is changed to the wave with frequency changed following the humidity changing through the humidity switch circuit to input the computer pin of the SCM. The output end of the SCM is connected with the liquid crystal display. The investigating instrument is of a simple structure, which not only can investigate the temperature but also the humidity.

Description

Temperature, humidity measurement instrument

Technical field

The utility model relates to the instrument of measuring temperature and humidity.

Background technology

Yet there are no one before the utility model is made can detected temperatures, can detect the instrument of humidity again.Usually the temperature monitor in usefulness comprises the plurality of temperature sensor, a plurality of multiway analog switches, a plurality of multi-channel a/d converters and single-chip microcomputer, the temperature sensor of each test point links to each other with single-chip microcomputer through the multichannel switching of analog switch and A/D converter, when test point is a lot, its circuit is just very complicated, and because the interface limited amount of single-chip microcomputer also makes thermometric counting be restricted.

Summary of the invention

The utility model be to provide a kind of simple in structure, can detected temperatures, can detect temperature, the humidity measurement instrument of humidity again.This detector comprises single-chip microcomputer, temperature sensor, humidity sensor, humidity change-over circuit and LCD, the output terminal of temperature sensor links to each other with single-chip microcomputer, the output of humidity sensor converts the counter pin of frequency with the waveform input single-chip microcomputer of humidity variation to through the humidity change-over circuit, and the output terminal of single-chip microcomputer links to each other with LCD.

Usually, for realizing multipoint temperature measuring, temperature sensor wherein can be connected in parallel with the plurality of temperature sensor and form.

Temperature of the present utility model, humidity measurement instrument, by temperature sensor temperature is directly changed into digital quantity and is transferred to computing machine, the size of numeral is with regard to the representation temperature height, to be converted into humidity from the waveform frequency of humidity change-over circuit with single-chip microcomputer, can be implemented in direct displays temperature of display and humidity value, when measuring multi-point temp, owing to link to each other with single-chip microcomputer again after the parallel connection of plurality of temperature sensor, so count can be not restricted because of the interface quantity of single-chip microcomputer in temperature survey.

Description of drawings

Fig. 1 is the utility model principle of compositionality block diagram;

Fig. 2 is a kind of instantiation of the utility model.

With reference to Fig. 1, temperature of the present utility model, humidity measurement instrument comprise single-chip microcomputer U1, temperature sensor U2, humidity sensor U3, humidity change-over circuit U4 and LCD U5, the output terminal of temperature sensor U2 links to each other with single-chip microcomputer U1, the output of humidity sensor U3 converts the counter pin of frequency with the waveform input single-chip microcomputer of humidity variation to through humidity change-over circuit U4, and the output terminal of single-chip microcomputer links to each other with LCD U5.

Embodiment

Referring to Fig. 2 instantiation, single-chip microcomputer U1 adopts 89C2051 in this example, temperature sensor is by N DS18B20 temperature sensor U2-1, U2-2 ... U2-N is in parallel to be constituted, end after the parallel connection links to each other with the P3.3 pin of single-chip microcomputer 89C2051, the sequence number of each temperature sensor is stored in the single-chip microcomputer respectively, the temperature sensor of the corresponding different measuring point of different sequence numbers, can realize the temperature survey of N point, here, it is capacitive that humidity sensor U3 adopts HS1101, humidity change-over circuit U4 is the multivibrator that constitutes with NE555 and Resistor-Capacitor Unit, the output terminal of humidity change-over circuit links to each other with the T0 pin of single-chip microcomputer 89C2051, and the frequency height of humidity change-over circuit output waveform is just represented the humidity size, is measured the frequency of waveform by single-chip microcomputer, and being converted into humidity, LCD U5 adopts HD44780.

Use for convenient, can insert keyboard, show so that multi way temperature is carried out the button switching at the parallel I/O pin (as the P3.5 pin among the figure) of single-chip microcomputer.

Claims

1. temperature, humidity measurement instrument, it is characterized in that it comprises single-chip microcomputer [U1], temperature sensor [U2], humidity sensor [U3], humidity change-over circuit [U4] and LCD [U5], the output terminal of temperature sensor [U2] links to each other with single-chip microcomputer [U1], the output of humidity sensor [U3] converts the counter pin of frequency with the waveform input single-chip microcomputer of humidity variation to through humidity change-over circuit [U4], and the output terminal of single-chip microcomputer links to each other with LCD [U5].

2. by the described temperature of claim 1, humidity measurement instrument, it is characterized in that said temperature sensor [U2] is by N temperature sensor [U2-1], [U2-2] ... [U2-N] is formed in parallel.

3. by the described temperature of claim 1, humidity measurement instrument, it is characterized in that said humidity change-over circuit is the multivibrator that is made of NE555 and Resistor-Capacitor Unit.

4. by the described temperature of claim 1, humidity measurement instrument, it is characterized in that inserting keyboard at the parallel I/O pin of single-chip microcomputer.