How to judge if there is a problem with the DC-DC isolated power supply module?

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How to judge if there is a problem with the DC-DC isolated power supply module? [Copy link]

IB0505S is a DC-DC isolated power module, with a 5V input and a 5V output. Its main purpose is to isolate the input and output (the input and output do not share a common ground). The input voltage range of this module is 4.75V~5.25V, and the output voltage is 5V. The output current depends on the output power of the module. If it is 1W, the maximum output current is 200mA, and if it is 2W, the maximum output current is 400mA. The following figure shows an IB0505S power module with an output power of 2W.

How to detect whether the IB0505S power module is good or bad? (1) Use the ohm range of a multimeter to detect the resistance between its input and output ends, which is generally around a few KΩ. It is best to compare it with a good IB0505S power module. If the resistance value is significantly different, it means that the module has a problem. (2) The resistance measurement method is not accurate enough and can only roughly determine whether the module is faulty. If you want to more accurately measure whether the power module has a problem, it is best to connect the input power supply and test the output with load. You can test it at half load and full load.

The principle is shown in the figure above. In this principle, both the input and output ends are added with π-type filters. This is designed to prevent electromagnetic compatibility. If the electromagnetic compatibility requirements are not high, the π-type filter can be removed and a capacitor can be connected to each input and output end. If the power module is 2W, connect a 25Ω resistor (half load) to the output end, and then measure whether the output voltage is about 5V±0.2V; then connect a 12.5Ω resistor or 13Ω (close to full load), and then measure whether the output voltage is about 5V±0.2V. If the output voltage meets the full load requirement, it means that the power module is intact. (3) Note: When measuring the voltage of the power module, it must be tested with load, and the output voltage test must be covered under full load, because when the power module fails, the no-load output voltage is very likely to be different from that under load. It is also possible that the no-load test voltage output is normal, but the voltage is significantly lower after loading. (4) If necessary, the power module can be tested at high and low temperatures under half load and full load. The temperature range is based on the temperature level of the chip, such as -40℃~+85℃.

Summary: The method to measure whether the power module is faulty is as follows: (1) First, measure the internal resistance of the input and output terminals when the power is off. If the internal resistance of the output terminal is very small and almost in a short-circuit state, it means that there is a problem with the load at the back end of the power module, or the power module itself is short-circuited. The load of the power module can be disconnected and then its internal resistance can be measured. If it returns to normal, it means that the problem is with the load at the back end of the power module. If it is still short-circuited, it means that there is a problem with the power module itself. (2) If there is a short circuit between the input and output terminals of the power module, power the power module with load to test whether its output voltage is normal. If the module output voltage is normal when tested in the circuit, but the circuit has experienced occasional faults before and the fault cannot be reproduced at present, and it is still suspected that the module has a problem, the power output load can be increased until it is fully loaded, and then its voltage can be measured to see if it meets the requirements to determine whether the output voltage of the power module is unstable when the load is too large. (3) The output voltage of the power module may be unstable due to different working environment temperatures. To eliminate this possibility, the power module can be tested for high and low temperatures when fully loaded. For example, if the working temperature of the power module is -40℃~+85℃, the output voltage of the power module can be measured at low temperature of -40℃ and high temperature of 85℃ to see if it is normal. If it is normal, it proves that the power module is intact.

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When judging whether there is a problem with the DC-DC isolated power module, the following aspects can be considered: Output voltage stability: Check whether the output voltage is stable within the predetermined value range. Use a suitable measuring instrument (such as an oscilloscope or digital voltmeter) to monitor the output voltage and observe its fluctuations. If the output voltage has obvious fluctuations, is too high or too low, it may indicate that there is a problem with the isolated power module. Overload protection: Observe the performance of the isolated power module when it reaches the rated load by gradually increasing the load. If the isolated power module cannot stably provide the current required by the rated load, there may be a problem with overload protection or output current limitation. Temperature detection: Observe whether the temperature of the isolated power module is normal. If the surface of the module is overheated or there is an abnormally high temperature phenomenon, there may be a heat dissipation problem or a circuit problem. Input and output short-circuit protection: Test the short-circuit protection function by shorting a load between the input and output. If the isolated power module does not have effective short-circuit protection measures, it may cause module damage or failure. Noise and ripple: Use an oscilloscope or spectrum analyzer to detect noise and ripple in the output voltage. If the noise or ripple exceeds the specified range, it may indicate that there is a problem with the isolated power module. Efficiency: Check the efficiency of the isolated power module to ensure that it can convert input power into output power with high efficiency. Low efficiency may mean energy loss or other problems. If you suspect that there is a problem with the isolated power module, it is recommended to refer to the module's technical specifications, the test methods provided by the manufacturer, or consult relevant technical support. Pay attention to safety during testing to avoid touching high-voltage parts or causing unexpected situations such as short circuits.

菜菜菜菜非常

This is my first time using an isolated power module. How is the input current calculated? The no-load output of a DC power supply is 20 mA. The manual says that the no-load output of 0505-1W is at least 5-10 mA. Is this normal? Thank you very much.

振动试验仪器

IB 0505 power modules are generally used at the input of optocouplers for power isolation. A 0.5 or 1W module can be connected to an optocoupler.

振动试验仪器

The driving circuit of high-power MOS tubes generally uses an isolated DC power supply. There are several driving circuits, and there are several DC-DC isolated power supplies. Generally, the failure of this power supply is no output voltage or the output voltage is too low. The high heat generation of the module is a precursor to damage.