Which two ranges of multimeter are commonly used for repairing motherboards?
When using a digital multimeter to repair the motherboard, there are several main gears used: 1: Diode gear: used to run lines, measure resistance to ground, and measure line continuity; 2: Electrical barrier is used to measure the resistance of the resistors in the motherboard. 3: DC 20V voltage block, because the highest voltage on the motherboard is only 12V. Repairing the motherboard mainly depends on measuring the resistance to ground and the voltage to ground to determine the fault. The measured current is too little.
What level should the analog multimeter be set to when testing the quality of a circuit?
You first need to know what exactly you want to measure.
Generally speaking, when measuring circuits, when the circuit is charged, the main purpose is to measure DC voltage, so the gear should be placed in the DC voltage range. As for which gear it is placed in, it depends on the condition of the circuit you are measuring. Measure DC The current is very small, because measuring the current requires disconnecting a certain point of the circuit for measurement.
When the circuit is not charged, the DC resistance of the circuit is mainly measured. Generally, the multimeter is placed in the 1K ohm range for most measurements. As for which points to measure, it depends on your familiarity and mastery of the circuit.
When measuring the motor control circuit while it is live, it is mostly measured at the AC voltage range.
You should read more books first and become familiar with various circuit principles and fault principles before talking about measurement issues.
What is the name of the function of a multimeter that is commonly used to test whether a wire is connected or not? Can any electrician friends please explain?
The multimeter can use the resistor X1 level to test the continuity of the wire, which is called the ohm level.
The ohm level measures resistance value, and the X1 level measures low resistance value. The resistance of the wire should be low. Short wires only have a few tenths of ohms. The resistance cannot be measured with an ordinary pointer multimeter. If the pointer hits zero, it means there is a circuit. If the pointer is less than zero, it means there is resistance in the circuit. If the pointer does not move, it means there is an open circuit.
Use a digital multimeter to measure it. A very small resistance value indicates a path, a certain resistance value indicates resistance in the circuit, and a very large resistance value indicates an open circuit.
Some digital multimeters have buzzers. The buzzer is generally in the 2 KΩ range. When measuring a line (or resistance) with a resistance value below 50 Ω, the built-in buzzer will sound. This function can actually improve the efficiency of measuring line continuity.
