Note on the maintenance of led power supply

Note on the maintenance of led power supply

A: First of all in the maintenance switch power supply, maintenance personnel must pay attention to when repair, if must be charged operation, first of all should make the body with the earth and reliable insulation, because using isolation transformer does not guarantee 100% safety, sufficient and necessary condition is caused by electric shock: physical contact with two or more than safe voltage potential difference between a conductor, and have a certain strength of the electric current flows through the human body. Although the use of isolation transformer can eliminate the potential difference between "hot ground" and the grid, it can prevent electric shock to a certain extent, but it cannot eliminate the inherent potential difference between the points in the circuit. In other words, if the maintenance personnel touch the switch power circuit at the same time with the electric potential difference, it will also cause the electric shock. So make it a habit to single hand operation, when must be charged contact, should prevent another hand or other parts of the body form a loop, or when sitting on a wooden seat, feet can step on a piece of dry plank or packing foam insulation; These are effective measures to avoid electric shocks.

B:If no output power supply, maintenance should be after electrify power again, due to the switch power oscillation, 300 v at the ends of the filter capacitor voltage discharge will be very slow, high pressure at the ends of the capacitor will keep for a long time, this time if the power is measured with a multimeter electric block, should be first to discharge of 300 v filter capacitor, and then to measure if not first to discharge of 300 v filter capacitor will not only damage the multimeter, would endanger the safety of the maintenance personnel.

C: There is a kind of liquid crystal display maintenance should be online and open the host power supply, because a lot of liquid crystal display in offline, or online but don't open the host state is not working, only when a display and a good host connection, and open the case that the host can enter into normal working status. Therefore, in order to avoid causing misjudgments to be online and open the host power.

D: When measuring voltage, must pay attention to the correct selection of ground, in the measurement, a switch power supply circuit should take the "re" as the reference point, earth (re) can choose grid rectifier filter circuit + 300 v filter capacitor anode, because + 300 v filter capacitance is a switch power supply circuit "markers", had better look for. When measuring the secondary voltage of switching power supply, the reference point should be "cold". If you don't pay attention to the correct selection of the ground line when measuring the voltage, it is likely that the test value will be wrong and may even cause the damage to the instrument.

E: When the waveform test is conducted, the selection of the corresponding ground line should be carried out. If it is too far from the waveform test, it is easy to get interference on the test waveform. Therefore, it is better to select ground wire near the test circuit.

F: When measuring voltage, must pay attention to the correct selection of ground, in the measurement, a switch power supply circuit should take the "re" as the reference point, earth (re) can choose grid rectifier filter circuit + 300 v filter capacitor anode, because + 300 v filter capacitance is a switch power supply circuit "markers", had better look for. When measuring the secondary voltage of switching power supply, the reference point should be "cold". If you do not pay attention to the correct selection of the ground line during the measurement of the voltage, it is likely that the test value will be incorrect and may even cause the damage of the instrument.

Please feel free to give your inquiry in the form below. We will reply you in 24 hours.
Message