Using LC filtering or power modules to isolate interference signals will cause the output voltage to decrease, which will eventually cause the display to show...

QWE4562009

Using LC filtering or power modules to isolate interference signals will cause the output voltage to decrease, which will eventually cause the display to show... [Copy link]

Using LC filtering or power module to isolate interference signals will cause the output voltage to decrease, which will eventually cause the display to be interrupted or abnormal.

1. Using a 47uH+1000uF LC filter circuit, L is connected in series in the DC12V circuit, and a 1000uF capacitor is connected in parallel to the power supply end of the display. As a result, the voltage at the display end is only 9.36V. What's going on?

2. Using a power isolation module, connect the DC12V to the input end of the module, and the output end of the module to the power supply end of the display. As a result, it is found that the power supply voltage at the display end is only 9.5V

or above. What are the reasons for the two situations?

beyond_笑谈

1. Use a 47uH+1000uF LC filter circuit, L is connected in series in the DC12V circuit, and the 1000uF capacitor is connected in parallel at the power supply end of the display screen. As a result, the voltage at the display screen end is only 9.36V. What's going on?

From the description, assuming the load end is normal, it seems that either the DC12V has an AC component, and the resonant frequency of the 47uH+1000uF LC filter circuit is close to the AC component frequency, or the DC12V cannot carry a capacitive load.

qwqwqw2088

What is the normal output if "LC filtering or power module is not used to isolate interference signals"

qwqwqw2088

Use LC filtering to pull down the voltage, the voltage is only 9.36V, which means that the selection is inappropriate, and ESR will reduce the voltage

The power isolation module usually uses a transformer to achieve electrical isolation, which has certain losses, including iron loss and copper loss. The loss will lower the voltage, which feels normal, but if it is lowered too much, it will not be suitable for use.