With the infrared tube to do a non coding infrared switch, a detailed analysis of the principle!
Release time：2021-6-28 10:42:18
This time, we can share a more effective small circuit, and we can also slightly modify it to make an infrared wireless remote control without number. Do you suddenly feel that you are very powerful! But this time we are all in the same circuit to complete this role, learn this and that will be very easy to make out, the following circuit diagram is what we want to describe today, all the circuits also use a lot of components, the production is not so complicated, especially suitable for novices.
Or let's first analyze the circuit diagram. When the switching power supply is turned on, the LED IR is already on. It's just that it's emitting infrared rays, which can't be seen at all. It's the same with the home controller. The function of series resistance R1 is to carry out over-current protection for the LED IR, so as to prevent its high current and voltage from burning the LED IR, Only when the triode BC548 is on, it will light up, because if the triode is not on, in fact, it has no current.
How to turn on the transistor here? In the infrared receiver, that is, the IR receiver in the circuit schematic diagram does not receive the infrared, the receiver is cut off. At this moment, there is no resistor in the resistor R2 passing through, so it does not meet the conduction standard of the triode. Therefore, the LED light is not on at this time. Conversely, when the receiver receives the infrared, it will turn on, and there will be electric flow through R2. At this moment, there will be a potential difference between the base and emitter of the triode. When the working voltage exceeds a certain standard value (different triodes are slightly different, and the silicon tube is about 0.7V), the triode will turn on, thus driving the LED light on.
This basic principle is relatively well understood, but the following matters must be paid attention to
Because there is infrared induction in the natural light, this circuit can also fail in the natural light, but you can also make a light controlled switch by giving full play to your imagination. The infrared emitting tube (LED IR) and the infrared receiving tube (IR receiver) do not have to be too close, otherwise the receiving tube will always be in the receiving situation, which will also cause the circuit failure. Note that there is no need to connect the long and short pins of the infrared receiver wrong. This is very easy to make mistakes. I also pay attention to this point on the circuit diagram.
This is the specific welding circuit of this circuit. Although it looks very messy, it is very easy to use. When the infrared tube is far away from the obstruction, the LED light does not light up, which indicates that the diode is not on at this time.
When the infrared tube is close to the obstruction, it is obvious that the LED lamp is illuminated at this time, and the triode is also turned on, which is the same as the basic principle of our analysis.
报错 笔记
Or let's first analyze the circuit diagram. When the switching power supply is turned on, the LED IR is already on. It's just that it's emitting infrared rays, which can't be seen at all. It's the same with the home controller. The function of series resistance R1 is to carry out over-current protection for the LED IR, so as to prevent its high current and voltage from burning the LED IR, Only when the triode BC548 is on, it will light up, because if the triode is not on, in fact, it has no current.
How to turn on the transistor here? In the infrared receiver, that is, the IR receiver in the circuit schematic diagram does not receive the infrared, the receiver is cut off. At this moment, there is no resistor in the resistor R2 passing through, so it does not meet the conduction standard of the triode. Therefore, the LED light is not on at this time. Conversely, when the receiver receives the infrared, it will turn on, and there will be electric flow through R2. At this moment, there will be a potential difference between the base and emitter of the triode. When the working voltage exceeds a certain standard value (different triodes are slightly different, and the silicon tube is about 0.7V), the triode will turn on, thus driving the LED light on.
This basic principle is relatively well understood, but the following matters must be paid attention to
Because there is infrared induction in the natural light, this circuit can also fail in the natural light, but you can also make a light controlled switch by giving full play to your imagination. The infrared emitting tube (LED IR) and the infrared receiving tube (IR receiver) do not have to be too close, otherwise the receiving tube will always be in the receiving situation, which will also cause the circuit failure. Note that there is no need to connect the long and short pins of the infrared receiver wrong. This is very easy to make mistakes. I also pay attention to this point on the circuit diagram.
This is the specific welding circuit of this circuit. Although it looks very messy, it is very easy to use. When the infrared tube is far away from the obstruction, the LED light does not light up, which indicates that the diode is not on at this time.
When the infrared tube is close to the obstruction, it is obvious that the LED lamp is illuminated at this time, and the triode is also turned on, which is the same as the basic principle of our analysis.
报错 笔记
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