Function introduction of the protection board

Function introduction of the main parts of the protection board R1: Reference power supply resistance; forms a voltage divider circuit with the internal resistance of the IC to control the level inversion of the internal overcharge and overdischarge voltage comparator. Generally the resistance value is 330Ω and 470Ω. When the package form (that is, the standard component The length and width indicate the size of the component. For example, the length and width of the component in the 0402 package mark are 1.0mm and 0.5mm respectively). When it is large, the resistance value will be marked by numbers. For example, the number mark 473 on the chip resistor indicates its resistance. The resistance value is 47000Ω or 47KΩ. R2: Over-current and short-circuit detection resistance; by detecting the voltage of the VM terminal to control the current of the protection board, poor welding or damage will cause the battery to over-current and short-circuit without protection. The general resistance is 1KΩ, 2KΩ and more. R3: ID identification resistor or NTC resistor (described earlier) or both. Summary: The resistor is a black patch in the protection board. The resistance value can be measured with a multimeter. When the package is large, the resistance value will be indicated by numbers. The method of expression is as described above. Of course, the resistance value generally has deviations. All resistors have accuracy specifications. For example, if the 10KΩ resistance specification is +/-5% accuracy, the resistance value is within the range of 9.5KΩ to 10.5KΩ. C1, C2: Since the voltage at both ends of the capacitor cannot change suddenly, it acts as an instant voltage stabilization and filtering.