#POWER SUPPLY DESIGN DESIGN PI FILTER FREE#

Thus, in such application, we can use L-section filters as its output voltage do not vary largely with load current. In an application where load current varies, pi filters are not suitable. Thus, this capacitor is not suitable for varying loads. Poor Voltage Regulation: We have discussed above that the output voltage varies with the load current.

High PIV: The peak inverse voltage in the case of Pi filters is more in comparison to L-section filter.

#POWER SUPPLY DESIGN DESIGN PI FILTER FREE#

Thus, a low ripples factor signifies regulated and ripple free DC voltage. A low ripple factor means the ratio of current due to AC ripples and direct Current is low. This leads to decrement in ripple factor. Low Ripple factor: Due to the involvement of 2 capacitors in addition with one inductor it provides improved filtering action.Pi filter’s significance is that it offers low voltage drop across choke coil and capacitor C 2 in order to main high output voltage across its output terminals. High Output Voltage: If you are dealing with the application which requires high output voltage after filtering, then this is the filter you should use.This is because the output voltage drops rapidly with the increase in current flowing through the load.Īpart from the above-mentioned disadvantage, its most crucial advantage is low ripple factor. But in addition to this high output voltage, the voltage regulation of Pi filter is very poor. Thus, this is the advantage of Pi capacitor that it provides high voltage gain. The voltage drop across choke coil and capacitor C 2 is quite small. The high voltage is obtained at the output of Pi filter, the reason behind this high voltage output is that the entire input voltage appears across the input capacitor C 1. The residual AC ripples are filtered by inductor coil L and capacitor C 2. In pi-filters, the major filtering action is accomplished by the capacitor at input C 1. The Pi filter has the characteristics to generate a high output voltage at low current drains. Thus, Pi filter is considered more efficient. In the case of L-section filter, one inductor and capacitor were present so if some AC ripples say 1% is left after filtering that can be removed in Pi-filter. In this way, the efficiency of filtering increases multiple times. The residual AC components which are still present in filtered DC signal gets filtered when they pass through the inductor coil and through the capacitor connected parallel across the load. Therefore, most of the AC ripples get bypassed through the capacitor in input stage only. The capacitor provides a low impedance to AC ripples present in the output voltage and high resistance to DC voltage. The output from the rectifier is directly applied to the input capacitor. Thus it is a crucial need to remove these AC ripples to improve the performance of the device.

The output voltage coming from rectifier also consist of AC components. The filters we have discussed in our previous articles are also efficient in removing AC ripples from the output voltage of rectifier, but Pi filter is more efficient in removing ripples as it consists of one more capacitor at the input side. The ultimate aim of a filter is to achieve ripple free DC voltage. Significance of Capacitor input filter or Pi filter (π- filter)

Power supply design design pi filter