Application of multimeter in ATX power supply maintenance
The multimeter is an essential measuring instrument for maintenance. Although any multimeter can be used for the maintenance of switching power supplies such as ATX, the digital one is better than the pointer one, and the automatic range one is better than the non-automatic range one.
The multimeter has the following uses in ATX power supply maintenance:
1. Measure the voltage of the test point and the resistance to ground
2. Judging the straightness between the test points
3. Measure the resistance value of the resistor
4. Measure the capacity of the capacitor within the measuring range
5. Measure a certain current
The function of the diode block of the digital multimeter:
The diode block of the automatic range digital multimeter generally has 3 function options: resistance, resistance buzzer, diode voltage drop buzzer
1. Resistance option: the dimension is resistance, which is used to measure the real resistance value between the red and black test leads.
2. Resistance buzzer option: the dimension is resistance, which is used to determine whether to buzz according to the set buzzer resistance. If the real resistance value between the red and black test leads exceeds the buzzer resistance, the multimeter will not buzz. then beep.
3. Diode voltage drop buzzer option: When the multimeter is in the diode buzzer option, the red pen of the multimeter is charged with voltage. When the voltage drop between the red and black pens is light and the buzzer is dropped, the multimeter will beep, otherwise it will not beep.
Conclusion: When the reading is small, the display value of the non-automatic range digital multimeter is the same as the real resistance value between the two points under test. As the real resistance value increases, the multi-meter indication value deviates more and more from the real resistance value between the two points. , but whether its dimension is resistance ohms or voltage volts, it will not affect the measurement process and the judgment made based on the measured value.
