| 摘要 |
A power supply circuit is configured for simulating the maximum standard load currents for different kinds of USB ports, and each of the USB ports includes a power terminal; the load-testing circuit includes a voltage regulating circuit, a voltage dividing circuit, a first operational amplifier, a first transistor, and a current limiting resistor. The voltage regulating circuit is configured for supplying a reference voltage to the voltage dividing circuit. The reference voltage is divided by sub-circuits of the voltage dividing circuit. When the sub-circuit connected to the voltage regulating circuit and the first operational amplifier is changed, a current flows from the first transistor and the current limiting resistor is changed. |
