Why are some power supplies connected in series with 0.05R and others connected in series with 0.1R? Can you explain? Is it a reserved place for subsequent EMI rectification or what is the reason?
Lorenzo 发表于 July 15, 2020
In the stickers you provided, I didn't see an RC and then stringed an R.
R can be changed back and forth, it can be changed to L, magnetic beads, PTC, etc., and even 0R0 resistance can be used.
It depends on how the original is understood. How much effect can a 0.05R or 0.1R resistor on the power supply pin of the chip have? I personally feel that it has no effect.
Camille 发表于 July 15, 2020
Do you see a capacitor behind each resistor! This is the design of RC filtering.
However, the current resistance is very small, only 0.1R and 0.05R, the role of RC is not very obvious
The original circuit design is reserved for future problems. If you really need RC, then adjust the value of R in the future, or you can change it to LC, or you can change it to bead + capacitor.
Dustin 发表于 July 15, 2020
I think many people say that it is RC filtering. I haven’t seen anyone filtering on the power supply. The usages I have seen are the following. 1. Do current detection, read the voltage value across the resistor through the amplifier or compare Conduct current detection and overcurrent shutdown after the device. 2. Do current limiting, use the voltage divider of the resistor to reduce the power supply at the load end of the power supply, such as 0.05R resistor, load current 10A, and the resistor divider voltage is 0.5V, but this resistance value is indeed Smaller, 3. Use as a fuse, there is a resistance type fuse, which uses the heating characteristics of the resistor to achieve the fusing effect. When the normal circuit is under the rated power, it can be used normally. When the circuit is overcurrent or abnormal, the resistance power Blow up.
Erika 发表于 July 15, 2020
Generally, this kind of resistance is mainly used to facilitate the measurement of the current consumption of the power supply. As for 0.1 or 0.05, it is mainly related to the power. The larger the current, the smaller the resistance of the string, but this is generally only debugged during the first evaluation. Use (especially to power the CPU) will be removed when it is measured to be mature.