Power is applied to the emitter junction through a resistor, and the emitter junction is forward biased. The majority carriers (free electrons) in the emitter region continuously cross the emitter junction and enter the base region, forming an emitter current. At the same time, the majority carriers in the base area also diffuse to the emitter area, but since the majority carrier concentration is much lower than the carrier concentration in the emitter area, this current can be ignored, so it can be considered that the emitter junction is mainly an electron flow.
After electrons enter the base region, they first become dense near the emitter junction, gradually forming an electron concentration difference. Under the action of the concentration difference, the electron flow is prompted to diffuse in the base region toward the collector junction, and is pulled into the collector by the electric field of the collector junction. The collector current is formed in the region. There is also a small part of the electrons that recombine with the holes in the base area. The ratio of the diffuse electron flow and the recombination electron flow determines the amplification capability of the triode.
Since the reverse voltage applied to the collector junction is very large, the electric field force generated by this reverse voltage will prevent the electrons from the collector area from diffusing to the base area, and at the same time, the electrons that have diffused near the collector junction will be pulled into the collector area to form the main collector area. current. In addition, the minority carriers (holes) in the collector area will also drift and flow to the base area to form a reverse saturation current. The value is very small, but it is extremely sensitive to temperature.
The output voltage of a single germanium diode is relatively small and cannot directly drive a triode. Then a certain voltage must be added to actively provide potential to the triode. There are several ways to provide potential to the base of the transistor. A power supply can be used to provide the potential at the base of the transistor, usually related to the voltage difference between the collector and emitter. You can use two resistors in series to provide the potential of the base of the transistor by dividing the voltage. This method is usually used to adjust the size of the base potential. Another option is to add an additional diode.
After checking, there is a place where the diode added to the base is not soldered properly. After re-soldering, providing enough voltage to the base, the amplifier can work again.
Xinyuan said: "Did you do testing in the laboratory?"
Li Rong said: "I was in a hurry when I came here, and some of them were not tested. I brought them over directly because I wanted to try them under the sun."
When there is no light, the photovoltaic-ampere characteristic curve is the same as that of an ordinary semiconductor diode. When there is light, it translates along the direction of the current axis, and the translation amplitude is proportional to the illumination. The intersection point of the curve with the voltage axis is called the open circuit voltage, and the intersection point with the current axis is called the short circuit current.
The open circuit voltage of a photovoltaic cell is related to illumination, temperature, material, photogenerated current, and reverse saturation current. Light intensity is one of the important factors affecting the open circuit voltage of photovoltaic cells. When the light intensity increases, the output voltage of the photovoltaic cell also increases. The relationship between open circuit voltage and light intensity is nonlinear, and it is linearly related to the logarithm of light intensity.
The short-circuit current of the photovoltaic cell is related to the frequency of the light wave, illumination and other parameters. There is a linear relationship between short-circuit current and illumination. The current through the external loop is equal to the photocurrent minus the diode forward current.
The open circuit voltage and short circuit current under different illumination conditions can be measured experimentally. Adjust the irradiation intensity of the adjustable light source and observe the changes in the output current and voltage of the photovoltaic cell. Under a certain light intensity, record the short-circuit current value of the photovoltaic cell. Repeat the above steps under different light intensities to obtain multiple sets of short-circuit current data. Based on the recorded data, analyze the relationship between the short-circuit current of the photovoltaic cell and the light intensity.
Xinyuan said: "How can we try it if there is no sun?"
Li Rong said: "Solar panels can be charged with light, and the light from incandescent lamps is better. But the light that is too weak, or the light with a lighter color will have a poor effect and the charging effect will not be ideal. LED lights, energy-saving lamps, etc. It’s difficult to achieve effective charging with cold light.”
Xinyuan said: "Look, there are a lot of clouds floating in the distance. Is the rainy season coming?"
Li Rong said: "I don't know what's going on. Do you feel that the wind is strange recently?"
Xinyuan said: "It's been very windy recently."
Li Rong said: "And sometimes the sun shines brightly, but after a while it becomes cloudy."
At this time, he remembered the large wind turbines next to the city. He wondered if the weather had something to do with these wind turbines.
Xinyuan said: "Can solar panels work under cloudy weather?"
Li Rong said: "It can work sometimes. Although the solar irradiance is low on rainy or hazy days, the photovoltaic modules can still generate electricity in low-light environments."
Qi Yanliang went to a nearby tea shop. There was also a person sitting opposite.
"Aren't you still willing to take it out? This is a very ordinary city, not worthy of your protection."
"What the enemy wants us to give up is also a very precious and important thing. I don't know if you have heard of it. A poet said: I built a city. I destroyed it, but it grew on its own. Now this A city, in its growth stage, is like a sapling. When it is a sapling, you cannot tell what kind of towering tree it will grow into. All your judgments are based on what you see now. The things you reach are in front of you. But the things you really ignore are under your feet. You don’t know how much energy is hidden under your feet.”
"I think I already know that. But no one else does."
"Now we can no longer call you car thieves, you should be desolate people."
"You haven't been so straightforward before."
"This means I've done it."
"As long as you can hand over those energy gathering fields, your city can be prevented from being destroyed."
"But what I want to protect is the meaning of this city's existence."
"Do you want anyone else to hear this?"
"I want other people to hear what you're saying. And let them know that you and they are never on the same side."
"What do you think you are in the eyes of the interceptor and the overlord?"
"Of course we are friends."
"Friend? In the eyes of the Interceptor, you are just a clown. In the eyes of the Overlord, you are just cannon fodder."
"free."
"Are you ruining yourself?"
Qi Yanliang thought about it.
The desolate ones are making trouble and not doing great things. What the Overlord does is too crazy and may not last long. It's like a mutated, unstable body. Interceptor seems to be a mutation, but it is relatively stable.
Qi Yanliang thought to himself, "You don't know what kind of huge energy is hidden under this city, under your feet. This is something you have been ignoring. It's better that you come here, you will see it. Your sins, It will be exposed to the sun. When you think you have succeeded, no one can escape the reincarnation of heaven."
