General definition of ripple in low ripple power supply
2022-03-06

Since the DC stable low ripple power supply is generally formed by the AC power supply through rectification and voltage stabilization, it is inevitable that there are some AC components in the DC stability. This AC component superimposed on the DC stability is called ripple. The components of ripple are relatively complex, and its form is generally sinusoidal harmonic with frequency higher than power frequency, and the other is pulse wave with very narrow width. For different occasions, the requirements for ripple are different. For capacitor sophistication, no matter what kind of ripple, as long as it is not too large, it will generally not affect the quality of capacitor sophistication. For the power supply used in the program-controlled computer or audio equipment, there is not enough energy to push the paper basin of the horn or the earpiece of the telephone due to the narrow pulse width, resulting in noise. Therefore, the requirements for this narrow pulse can be relaxed.


For the sinusoidal ripple signal in the audio range, although its amplitude is not too high, its energy makes the horn or earpiece produce buzzing noise. Therefore, there should be certain requirements for this form of ripple. For some control occasions, because the narrow pulse reaches a certain height, it will interfere with the digital or logic control components and reduce the reliability of equipment operation. Therefore, there should be a certain limit on the amplitude of this narrow pulse, while for the ripple similar to sine wave, it generally has little interference to the control components because of its low amplitude.


The ripple of special power supply can be expressed by effective value or peak value, absolute quantity or relative opposite quantity. For example, a power supply works in a regulated state, its output is 100v5a, and the effective value of the measured ripple is 10mV. This 10mV is the absolute amount of ripple, and the relative amount is ripple coefficient = ripple voltage / output voltage =10mv/100v=0.01%, which is equal to one in ten thousand.