Helsinki power adapter custom manufacturers
Main products: power adapter, medical power, LED power, charger and so on.
Shenzhen Lianyunda Electronics Co., Ltd. is committed to doing a good job in power supply products, and sincerely welcomes customers to contact us by phone or email.
The Unicom power adapter has strong compatibility, wide application range, high work efficiency, high cost performance, environmentally friendly wire, high quality material selection, stable output, long life and safety. Buy a power adapter and find Shenzhen Intermodal Electronics.
Power adapter output rectifier rated current
In the current interrupted operation state of the flyback power adapter converter, the peak value of the current flowing through the rectifier is 4 times or more of the average value of the output current. Therefore, when selecting the output rectifier, the average value of the output current should be 3-5. Times as the output rectifier rating.
Analysis of working state of power adapter output filter capacitor
For the small and medium output power adapter, the duty rate is still limited to 50% or more due to price restrictions. Most of them are above 50H; DCDC power modules are mostly above 300H: the switching rate of the high-power power adapter is controlled by the main switch (generally The switching speed limit of EGBT is generally about 20=40%. Although the switching frequency is different, the output rectifying and filtering capacitors of the power adapter function basically the same, mainly by using the filter capacitor to absorb (in terms of circuit, In fact, the low-impedance of the capacitor is used to make most of the AC current component, and it is more desirable to flow all the parts to the filter capacitor so that the output current has no or very low AC current component. The switching frequency and its harmonic rate The current component, thereby filtering out its ripple voltage component.
Since the flyback power adapter operates in the state of the sawtooth current and contains more abundant current than the rectangular wave, this requires that the filter capacitor should have a good impedance ratio characteristic, which is required for the capacitor with the power frequency rectification filter. The difference in capacitance (power frequency rectification filter can easily filter the harmonics of the power frequency, even if it is 40 times, it is only 2000, the general electrolytic capacitor is easy to implement). Therefore, the output rectifier filter capacitor of the power adapter even uses aluminum electrolytic capacitor. Aluminum electrolytic capacitors with good impedance frequency characteristics should also be preferred, and no aluminum electrolytic capacitors (as long as voltage and large-capacity load requirements) can be caught in the electronics market. The result of this will be the output ripple of the power supply. The voltage is too high, especially if the peak voltage is too high.