CBB capacitor is a polypropylene capacitor with a relatively simple structure, consisting of two parallel charged plates and an insulating medium sandwiched between them. This capacitor is characterized by its small size, moderate stability, and similar performance characteristics to polystyrene capacitors. CBB capacitors are famous for their non-polarity, large capacity, high stability and excellent self-healing properties. They also have high insulation resistance, excellent frequency characteristics and extremely low dielectric loss. This kind of capacitor can withstand the impact of high voltage and large current, has small loss and good electrical performance. Although the temperature coefficient is large, it is widely used in high-frequency and high-voltage circuits.
CBB capacitors play an important role in various electronic equipment, such as instruments, meters, televisions and household appliances. They are used for DC pulsation and AC voltage reduction, and are especially suitable for electronic rectifiers and energy-saving lamp circuits. Due to its non-polar and high-frequency characteristics (broad frequency response), CBB capacitors also play a key role in high-voltage potential absorption lines.
In view of the widespread use of CBB capacitors, it is particularly important to master their detection methods. For small capacitors below 10pF, due to their small capacity, measurement with a multimeter can only qualitatively check whether there is leakage, internal short circuit or breakdown. In this case, you can use the R×10k block of the multimeter for detection. The resistance of the multimeter should be infinite. If the measured resistance value is zero, it indicates that the capacitor has leakage or internal breakdown.
When testing CBB capacitors ranging from 10pF to 0.01μF, you should use the R×1k block of a multimeter to observe whether the capacitor is charging to determine whether it is good or bad. The amplification effect of the composite transistor can be used to amplify the charge and discharge process of the capacitor under test, so that the swing range of the multimeter pointer is increased, making it easier to observe. During testing, especially for capacitors with smaller capacities, the contact points of the capacitor pins should be repeatedly changed to clearly observe the swing of the multimeter pointer.
For CBB capacitors with a capacity above 0.01μF, you can directly use the R×10k scale of a multimeter to test whether the capacitor is charging and whether there is an internal short circuit or leakage. By observing how much the pointer swings to the right, you can estimate the capacitance of the capacitor. This method is simple and effective and suitable for many types of CBB capacitance detection.