I'm Mr Tuan
Region: VN
Saturday 04 July 2026 07:40:48 GMT
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Lưu Cường :
7805 tối đa 1ah thêm mosfet tăng dòng ok hơn
2026-07-05 18:16:32
0
XD :
quien controla la carga?
2026-07-05 18:58:16
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zerzor :
If you connect any device (such as a smartphone) to this port, it will burn out immediately due to polarity reversal. Additional tip (not a mistake, but best practice): The 7805 voltage regulator typically requires a small ceramic capacitor (e.g., 0.1µF) on the output, in addition to the electrolytic capacitor, to prevent high-frequency fluctuations. Converting the voltage from 12V to 5V means there is a 7V difference that will be dissipated as heat. If the USB-connected device is drawing a high current (e.g., 1A), the regulator will become very hot and definitely needs a heatsink to prevent it from burning out or spontaneously shutting down.
2026-07-05 14:38:03
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B :
For once, almost correct.
2026-07-05 18:39:24
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durros :
no hay disipador para el 7805 que absorvera 12- 5 lo que equivale a 7 vdc además de la corriente no hay limitación de corriente tampoco
2026-07-04 18:05:37
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slava 12830 :
Слишком большие потери. Больше 50-ти процентов!
2026-07-04 17:33:18
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Heresh :
مبدع
2026-07-04 16:54:27
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zerzor :
The second and more serious mistake (connecting the USB port upside down) The blue 5V wire is connected to the bottom terminal of the USB port (as shown in the diagram), and the black ground wire is connected to the top terminal. In standard USB Type-A ports (when the internal plastic tab is facing up or down depending on the orientation), the power connectors are as follows: Pin 1 is VBUS (+5V), and Pin 4 is ground (GND). In the current diagram, the polarity is completely reversed on the USB port (positive to negative and negative to positive).
2026-07-05 14:37:07
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zerzor :
The first mistake (connecting the LED upside down) The positive terminal of the LED (anode) is connected to the 5V line (output), while the negative terminal (cathode) is connected to the resistor and then to the ground (GND) line. This connection is correct in terms of polarity, but the mistake lies in the internal design of the LED. If you look at the internal solder joint of the LED (the anode and cathode inside), you will find that the terminal connected to 5V is the cathode (the larger piece inside). However, the positive (+) sign on it means the LED is connected upside down and will not light up.
2026-07-05 14:35:59
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zerzor :
The circuit shown in the image is a voltage regulator circuit. Its primary function is to reduce the DC voltage from 12V to a stable DC voltage of 5V, suitable for powering USB ports or 5V devices. Upon closer examination of this diagram, two critical wiring errors can be identified that will damage the components or cause the circuit to malfunction:
2026-07-05 14:34:45
0
Lưu Cường :
chỉ sạc được máy cục gạch pin dung lượng thấp thôi
2026-07-05 18:14:02
0
منصة هرجاب للتدريب :
How to control the amperage, out from the USB
2026-07-04 10:20:09
1
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