I take the repeater power cord down, ready to connect USB line for mobile hard disk power supply, repeat machine two lines, one is black, and one is black and white, which is the positive pole, which is the negative pole? What happens if the answer is reversed?
With a multimeter, multimeter to maximum range, red and black pen respectively connected with one line, if the reading is positive, then the red pen line is connected, if the reading is negative, then the table is connected with a black pen. If the pointer multimeter, if the pointer clockwise deflection, so the red pen is connected; if the pointer counterclockwise deflection, so the black pen is connectedIt is customary to use the black line as a negative electrode. It is recommended that you use a multimeter to measure it so as not to make mistakes
Standard line, black line is negative. If the two lines are of the same color, then there is a lot of online printed text. If you have a multimeter or voltmeter, measure it immediately.
The power line is the wire that transmits the current. Usually, the current is transmitted by point to point transmission. Power line can be divided into AC AC power line and DC DC power line according to the application, usually AC power line is high voltage alternating current through the wire, the wire due to the higher voltage to obtain uniform standard safety certification to formal production. The DC line is basically through the lower voltage DC, so the safety requirements and no AC line strict, but for safety sake, at present, countries still require unified security certification.
With a multimeter, multimeter to maximum range, red and black pen respectively connected with one line, if the reading is positive, then the red pen line is connected, if the reading is negative, then the table is connected with a black pen. If the pointer multimeter, if the pointer clockwise deflection, so the red pen is connected; if the pointer counterclockwise deflection, so the black pen is connected.
