We all know about power adapters, but I believe many of us are unfamiliar with the aging test of power adapters. Next, Richupon Adapter Manufacturers will introduce the aging test of power adapters for you.
The burn-in test simply means that the power adapter is working at full capacity over a period of time to see what problems the power adapter may have. Of course, one has to ask, how long is a period of time? 1 day? Two days? It is common practice to age for at least a few hours, depending on the quality and cost of the adapter. In fact, a little more popular understanding, the aging test is actually a very cruel destructive test, because only by doing so, flow to the client is the product of the perfect product, good power adapter manufacturers will only sell these good products to the customer. In fact, this is the next question I will explain, why should the power adapter do the aging test?
In fact, many power adapter products on the market are not tested for aging, why say so? First, the general flow of power adapter products from production line for the most part had already has all of its functions, can be used directly, but if you don't do aging test at the beginning of the power supply using will may appear many problems, such as short circuit, voltage, current, and even explosion is likely, but these questions completely avoided after finished aging test, use a year or more, of course, there is a problem, that is the life of the power supply problem, this is no way to control.
This problem can't say so absolutely, of course, we are just in theory analysis results, because does not exclude you bought fake products did aging test, but is no problem to use, perhaps with a one year two years did not appear problem, but did aging testing power adapter products more secure.
Switch power adapter test
In the new product research and development and experiment process of switch power adapter, the inspection link is a very important process, and it is necessary to pay attention to it. When testing new products of switching power adapter, engineers often use oscilloscope to finish debugging. So, what questions should we pay special attention to during debugging?
1. Debugging security
In the new product debugging process of switching power adapter, safety question is the first, followed by the accurate application of power and surface together. In debugging, it is particularly necessary to pay attention to the primary primary circuit of the switching power supply, which has a high voltage of hundreds of volts or even thousands of volts. However, the negative pole of the primary primary circuit of the switching power supply is not zero voltage, so once the human body touches the end, it will be shocked, which will endanger the personal safety of engineers. A ground connection at the same end may constitute a power short circuit that damages the input rectifier.
Therefore, it is necessary to end electrical isolation by isolating transformer when debugging switching power supply. After isolating the transformer, the negative pole of the primary circuit can be directly connected to the probe ground end of the oscilloscope, and connected to the maintenance ground wire of the power supply system through the single-phase three-wire plug of the oscilloscope, so as to eliminate the potential safety hazard. If the oscilloscope with built-in isolation channel skill is used by the skilled personnel in the debugging process, then the measurement can be made directly even without connecting the isolation transformer. There will be no short-circuit phenomenon, but the human body will be shocked when contacting the primary circuit. Therefore, the best commissioning switch power adapter process is still access isolation transformer.
2. Key waveform
In the process of testing new products of switching power adapter, it is also very important for engineers to check the key waveforms. When using oscilloscope to check, the drain voltage waveform of power switching tube can directly reflect the drain peak voltage, secondary reflection voltage, switch tube conduction voltage drop and other information. Even if the input voltage is very small, when the drain absorption circuit is open, it will constitute a very high drain peak voltage, and then constitute a power switch breakdown damage, requiring special attention from the engineer. In addition, assuming that the power switch tube cannot fully conduct, it will constitute a large power loss, resulting in the switch tube overheating damage. Close attention to drain voltage waveform, can be sensitive to find the occurrence of dangerous situation, in order to close the power supply in time, to avoid component damage and greater loss. Selection and Connection of probe In the process of using oscilloscope to end the measurement of new products of switch power adapter, the engineer needs to select the appropriate probe according to the measurement mission at the time, so as to obtain the most accurate measurement effect.
For routine measurements, a 10-1 probe is sufficient, but for low cragging signals, consider using a 1-1 probe. When measuring high voltages, such as the source voltage of a switching power tube, a high voltage probe can be selected. Similarly, when using oscilloscope products to measure the current of the adapter test products, it is necessary to select the appropriate current probe.
In general, the input voltage of oscilloscope probes is mostly 400V (RMS) or 400VDC, which allows a certain peak voltage to exceed this plan in a short time. Assuming that the peak voltage is relatively high, the high-voltage probe should be selected. When using a current probe for inspection, try to connect it to a circuit where the voltage change is less rugged. For example, when measuring the drain current of a power switch, it should be connected to the source loop of the power switch to check the drain current directly. If connected to the drain circuit, the high frequency peak voltage of the drain will be more disturbing to the measurement. Reasonable setting of ground is also very important when using oscilloscope to inspect new products of switching power adapter. In the inspection process, it is assumed that the skilled person USES the probe grounding clamp to ground, which is equivalent to adding a series inductor to the grounding path. This series inductor in conjunction with the probe capacitance may cause vibration and overshoot. There is strong electromagnetic radiation in the switching power supply, and the probe grounding wire is too long, which may cause trouble. The peak current of the switching power supply adapter will attack the disturbing voltage on the circuit board, in different address measurement, the waveform will be different, waveform tremor is normal phenomenon.