LED lighting voltage and Countermeasures

More LED information, please click Real Green Lighting Company Limited

Leakage current settings

Here refers specifically to the leakage current leakage current test voltage generated for us in the test set alarm thresholds. For the current human reactions are: current perception: Male 1.1mA, female 0.7mA; get rid of the current: Male 9mA, female 6mA (probability 99.5%); fatal current (current VF): 50mA (current duration than the heartbeat cycle) , 500mA (the current duration of less than 0.1 seconds). When the current flowing through the human body than 10mA dangerous, people have electric shock. Therefore, under normal circumstances, the leakage current standard definition of the type test is 5mA. GB 7000.1, a type test section and not clearly defined pressure test leakage current, and in the factory type test appendix, specify the size of the value.

Pressure tests and breakdown tests

Standard specifies the specific voltage value of testing. After the pressure test only shows insulation product can withstand the test voltage, insulation product can not explain exactly how much can withstand voltage. If the design and application of electrical equipment, insulation materials, need to determine dielectric strength, breakdown test will be carried out. Breakdown voltage test is the test of dielectric breakdown when. When the electric field intensity exceeds a certain limit, by the relationship between current and voltage is applied to the medium, the medium does not comply with Ohm's law, but a sudden increase. Figure 1, then the insulating material is destroyed and lose insulating properties. For electrical products, if the insulation breakdown occurs, it loses its operational use features.

Part of the customer requirements in accordance with the type inspection testing standards, do one minute test, which is the product "100 victims without a beneficial": First, it may reduce the rate of qualified products; second, to pass the test though, may damage part of the insulating structure so reduce product safety; third, it may damage some of the components, the quality of the product is reduced, life cut short. Pressure test passed, does not mean lamps intact. In many cases, LED lamp beads can withstand type tests, but will result in the extension of the lamp is off, but because the actual casting off greatly reduced lamp life.

Test Methods

A typical pressure test methods:

1. Check that the voltage tester main power switch is in the "off" position;

2, unless special design of the instrument, all dead metal parts must be grounded;

3, the device under test all the power input wires or terminals connected;

4. Close the device under test all power switches, relays and other;

5, the pressure tester test voltage = zero;

6, the voltage tester of high-voltage output line (usually red) is connected to the power input of the device under test;

7, the pressure tester circuit ground wire (usually black) is connected to the device under test can be touched uncharged metal part;

8, the voltage tester main power switch is closed, slowly raising the secondary voltage of the instrument to the desired value, generally boosting speed does not exceed 500 V / sec speed;

9, the test voltage is maintained within a specified time;

10, the test voltage slowly down;

11, voltage tester off the main power switch. Disconnect the voltage tester high voltage output line, then disconnect voltage tester circuit ground wire.

The following represents the device under test does not pass the test:

1. When the test voltage can not be raised to a specified voltage or voltage instead falls;

2, pressure tester when a warning signal.

Note that, due to the presence of a risk of personal high voltage withstand test, the test must be particularly careful.

Matters requiring special attention:

1, must provide that only trained and authorized personnel can operate the instrument into the test area;

2, must be placed fixed, clear warning signs in the area around the test, to prevent others from entering the danger zone;

3, when tested, including all personnel, including the operator must stay away from the device under test and test equipment;

4, start testing equipment, do not touch its output lines.

Common mode voltage capability improvement

· Add isolation transformer, effectively reduce the secondary circuit withstand voltage value through the transformer;

· Increased dielectric strength, such as a plastic, add insulation pads;

• Improve board voltage capability: a, choose the ability to withstand high dielectric layer circuit boards; b, the board increased creepage distance.

As lamp beads arranged where the circuit boards, wiring space and creepage distances are mutually contradictory. To increase the creepage distance, only wiring space compressed as much as possible. Try to avoid using sharp objects, in order to reduce its cut insulating substance, or because the tip of the discharge pressure cause breakdown. Such as minimizing the use of self-tapping screws; circuit board design, rectangular copper at a suitable position, do excessive treatment.