Function introduction:
The colorful Christmas tree kit consists of two light boards and one light board base, which form a tree-like shape. The colorful LEDs on the edge of the two light boards alternately flash like water, automatically changing seven colors, at night. It looks radiant and illuminates the surrounding environment. It has a beautiful effect and can create a pleasant atmosphere. This kit is very capable of exercising the welding ability, suitable for practical training hands and enlightenment exercises for electronic production. It is a very good choice whether it is used for self-appreciation or as a gift.
Circuit principle:
18 LEDs are divided into 3 groups. When the power is turned on, 3 triodes will contend for conduction. However, due to the difference in components, only one transistor is turned on first. It is assumed that Q1 is turned on first, then D1 -D6 is lit. Because Q1 is turned on, its collector voltage drops so that the left end of capacitor C1 falls, close to 0V. Since the voltage across the capacitor cannot be abrupt, the base of Q2 is also connected to approximately 0V, Q2 is cut off. Therefore, the group D7-D12 connected to its collector is extinguished; at this time, the high voltage of Q2 increases the voltage of the collector of Q3 through the capacitor C2, and Q3 will also turn on quickly, and the group D13-D18 lights up, so During the period of time, the collectors of Q1 and Q3 are all low level, and the two groups D1-D6 and D13-D18 are lit, and the group D7-D12 is extinguished, but the power is charged to C1 through the resistor R3, Q2 The base voltage gradually rises. When it exceeds 0.7V, Q2 changes from the off state to the on state, the collector voltage drops, and the D7-D12 group illuminates. At the same time, the collector voltage of Q2 drops. C2 causes the base voltage of Q3 to also decrease, Q3 turns off from on, and its collector voltage rises, D13-D18 Set off, then, in accordance with the process loops circuit described above, three LED 18 will light up in turn, has two sets of the same time are lit, the cycle to continue flashing light, to achieve the effect of flow visualization.
The colorful Christmas tree kit consists of two light boards and one light board base, which form a tree-like shape. The colorful LEDs on the edge of the two light boards alternately flash like water, automatically changing seven colors, at night. It looks radiant and illuminates the surrounding environment. It has a beautiful effect and can create a pleasant atmosphere. This kit is very capable of exercising the welding ability, suitable for practical training hands and enlightenment exercises for electronic production. It is a very good choice whether it is used for self-appreciation or as a gift.
18 LEDs are divided into 3 groups. When the power is turned on, 3 triodes will contend for conduction. However, due to the difference in components, only one transistor is turned on first. It is assumed that Q1 is turned on first, then D1 -D6 is lit. Because Q1 is turned on, its collector voltage drops so that the left end of capacitor C1 falls, close to 0V. Since the voltage across the capacitor cannot be abrupt, the base of Q2 is also connected to approximately 0V, Q2 is cut off. Therefore, the group D7-D12 connected to its collector is extinguished; at this time, the high voltage of Q2 increases the voltage of the collector of Q3 through the capacitor C2, and Q3 will also turn on quickly, and the group D13-D18 lights up, so During the period of time, the collectors of Q1 and Q3 are all low level, and the two groups D1-D6 and D13-D18 are lit, and the group D7-D12 is extinguished, but the power is charged to C1 through the resistor R3, Q2 The base voltage gradually rises. When it exceeds 0.7V, Q2 changes from the off state to the on state, the collector voltage drops, and the D7-D12 group illuminates. At the same time, the collector voltage of Q2 drops. C2 causes the base voltage of Q3 to also decrease, Q3 turns off from on, and its collector voltage rises, D13-D18 Set off, then, in accordance with the process loops circuit described above, three LED 18 will light up in turn, has two sets of the same time are lit, the cycle to continue flashing light, to achieve the effect of flow visualization.
Component list:
common problem:
1. First declare that if the lamp is not lit after welding, this is not the quality problem of the lamp. This can be tested by testing the LED before soldering. The test voltage is 3.0-3.5V, not more than 3.5V. After welding, we have 50 sets. The test leads to the cause of the lamp being broken. The static electricity of the soldering iron damages the LED, the soldering burns the LED, and the bent pin damages the LED. Generally, if there are two lights, the two lights are not bright, and the two or three of us can be replaced. .
2. The welding sequence is recommended to first solder the components of the bottom plate, and then solder the resistors of the A and B lamp plates--LED--triode-electrolytic capacitors. The LEDs on the top of the A board are assembled and finally soldered.
3. The resistance value should correspond to the one-to-one identification on the board.
4. The LED lamp pays attention to the positive and negative poles, the long pin is the positive pole, and the welding LED lamp time is as short as possible to avoid burning the LED.
5. The triode is inserted in the shape of the board.
6. The electrolytic capacitor pays attention to the positive and negative poles, and the long pin is the positive pole.
7. After welding a light board, you can use the 5V power supply to connect the positive and negative poles under the board. Test to see if there is no light. If one of the lights is not bright, check the solder joint and the damage of the lamp and replace it. If the six lamps that are connected in parallel with the schematic diagram are not lit, check the short-circuit phenomenon of the welding of the six lamps. If they are not bright, check the soldering short circuit, the virtual soldering, and the poor power supply contact of the whole circuit.
8. When assembling the light board and the bottom board, pay attention to the one-to-one correspondence between the light board and the positive and negative poles of the bottom board.
Appendix: Specific identification methods for four-ring and five-ring color ring resistors
评论
发表评论