What is the principle of a thermal dioxide?

Thermal diodes.

The body consists of a thermistor.

Composition, the thermistor rises to a very high temperature resistance, and the current through it is very small, which is basically negligible, just like the diode does not conduct electricity in reverse, and the resistance becomes smaller when it encounters low temperature, just like the wire is so small, just like the diode is connected, the main thermistor works.

To put it simply, in a word: it is a one-way resistance made of materials that change significantly with temperature.

Thermal thermometer.

The thermistor uses a miniature semiconductor thermistor as a temperature measurement element, which responds quickly to temperature changes, has high sensitivity, small size and simple structure. It can be used in conjunction with a demonstration meter to form a thermal thermometer, which can be used for physical demonstration experiments.

The resistance of a semiconductor thermistor has a high temperature sensitivity, and a certain circuit is used to convert the change in the resistance of the thermistor into a change in current or voltage, which is displayed by the meter to reflect the change in temperature. The picture shows the circuit diagram of the J0301 thermal thermometer. In the figure, R1 is a semiconductor thermistor, R2 and R3 are the equivalent resistors of R1 at 100 and 0 respectively, R4 and R5 are the base bias resistance of the triode 3DG6, R6 and diode (2AP type) D are temperature compensation circuits, R7 with R4 is a semi-variable resistor for adjusting the linearity of the thermistor element, K1 and K2 are five-position double-pole band switches, which are used for working adjustment, where and gear are used to disconnect the power supply, W1 is an adjustable shunt set up to accommodate the sensitivity and internal resistance of different demonstration meters.

In fact, the temperature characteristics of the thermal diode were originally a problem with the diode: that is, the positive conduction voltage of Huiyuan changes with the change of temperature, so the general diode is to avoid this bug as much as possible when manufacturing. However, this feature makes it possible to measure the temperature accurately.

Therefore, the diode used for temperature measurement is the integration of two diodes connected in reverse parallel, so the characteristics of a diode will be measured by the forward and negative measurements of the multimeter, and the on-voltage cannot be measured (because the change of the former Zheng collapse is too small, at least the multimeter cannot be measured). So I suggest you try it out with a good one.

It is easy to measure its short circuit, and the short circuit is 0 ohms.

But the open road and the good ones are all liquid-free and disturb the poor and big.

You can heat the surface of the pin to see if the watch has changed, if there has been no change, it is an open circuit.

There is also a situation that cannot be measured, there are two inverting diodes inside, if only one of them is broken, then it cannot be measured. You can only use the substitution method to match it.

The principle of thermal printers is to cover a light color material with a transparent film, and heat the film for a period of time to become a dark color.

The image is created by heating and creating a chemical reaction in the membrane. This chemical reaction takes place at a certain temperature. High temperatures accelerate this chemical reaction.

When the temperature is less than 60, the film takes a very long time, even several years, to become dark; At a temperature of 200 °C, this reaction is completed in a matter of microseconds.

The thermal printer selectively heats the thermal paper at a determined position, from which the corresponding pattern is generated. Heating is provided by a small electronic heater on the printhead that comes into contact with the heat-sensitive material. The heater is logically controlled by the printer in the form of square dots or bars, which, when driven, produces a graphic corresponding to the heating element on the thermal paper.

The working principle of the thermal printer is that the print head is equipped with a semiconductor heating element, and the print head can print the desired pattern after heating and touching the thermal printing paper, which is similar to the principle of a thermal fax machine. The image is generated by heating and creating a chemical reaction in the membrane. This thermal printer chemistry is carried out at a certain temperature.

High temperatures accelerate this chemical reaction. When the temperature is below 60, the paper needs to go through a considerable length, even up to several years, to become dark; At a temperature of 200 °C, this reaction is done in a matter of microseconds.

Thermal paper is a special kind of coated processed paper, which is similar in appearance to ordinary white paper. The surface layer of thermal paper is smooth, it is made of ordinary paper as the paper base, and a layer of thermal chromogenic color layer is coated on the surface of ordinary paper, and the chromogenic layer is composed of adhesive, chromogenic agent, and colorless dye (or hidden dye), which is not separated by microcapsules, and the chemical reaction is in a "latent" state. When the thermal paper encounters the hot print head, the chromogenic agent and the colorless dye printed by the print head will undergo a chemical reaction and change color, forming **.

When the thermal paper is placed in an environment above 70 degrees, the thermal coating begins to change color. The reason for its discoloration also starts with its composition. There are two main types of heat-sensitive components in thermal paper coatings:

One is a colorless dye or a hidden dye; The other is a chromogenic agent. This type of thermal paper is also known as two-component chemical thermal recording paper.

Commonly used as colorless dyes are: crystal violet lactone (CVL), fluorane system, colorless benzoylmethylene blue (BLMB) or spiropyran system and other substances in the triphenylphthalide system. Commonly used as a chromogenic agent is mainly:

Para-hydroxybenzoic acid and its esters (PHBB, PHB), salicylic acid, 2,4-dihydroxybenzoic acid or aromatic sulfone.

After the thermal paper is heated, the colorless dye reacts with the chromogenic agent to produce color, so when the thermal paper is used to receive the signal on the fax machine and print or directly print with the thermal printer, ** is displayed. Since there are many varieties used as colorless dyes, the color of the handwriting displayed is different, such as blue, fuchsia, black, etc.

Thermal Printer: A printer that uses thermal technology to print documents.

Thermal reed relay is a new type of thermal switch that uses thermal magnetic materials to detect and control temperature. It is composed of a temperature-sensing magnetic ring, a constant magnetic ring, a reed switch, a thermally conductive mounting replicator sheet, a plastic substrate and some other accessories. The thermal reed relay does not use coil excitation, but is magnetically driven by a constant magnetic ring to drive the switching action.

Whether the constant magnetic ring can provide magnetic force to the reed switch is determined by the temperature control characteristics of the thermosensitive magnetic ring.

The operating power of electromagnetic relays comes from electromagnetic force. Thermal reed relays are powered by the thermal peristalsis of the bimetallic sheet.

Thermal paper is also known as thermal fax paper, thermal recording paper, thermal copy paper, and in Taiwan, it is called thermal copy paper. Thermal paper is a type of processed paper that is manufactured by applying a layer of "thermal paint" (thermal chromic layer) to a high-quality base paper. Among them, Hanyin's thermal printing paper is very easy to use, and the prints are stored for a long time, which is a rare choice of conscience.