Сјајна идеја
Дај малко детаљније да појасниш какав филтер шта и како у некој теми о DX-u.
Ovako nešto kao što je dole opisano, googluj LC Filters za power supply namenu. U principu imaš samo induktivitet i 1-2 konda, pa sve to x2 (za 5 i 12V posebno). Trafo i diode nisu potrebne jer mi iz PSU već imamo stabilisan DC. Mada nisam siguran da li DX koristi i 5 i 12, treba proveriti da mu se uskrati jedna pa druga voltaža i videti da li radi, ali ako koristi oba napona, onda su potrebna dva ovakva filtera.
LC Filters
A full-wave rectifier with filter capacitor.
While the RC filter shown above helps to reduce the ripple voltage, it introduces excessive resistive losses when the load current is significant. To reduce the ripple even more without a lot of dc resistance, we can replace the resistor with an inductor as shown in the circuit diagram to the right.
In this circuit, the two capacitors store energy as before, and attempt to maintain a constant output voltage between input peaks from the rectifier. At the same time, the inductor stores energy in its magnetic field, and releases energy as needed in its attempt to maintain a constant current through itself. This provides yet another factor that attempts to smooth out the ripple voltage.
In some cases, C1 is omitted from this filter circuit. The result is a lower dc output voltage, but improved ripple removal. The choice is a trade-off, and must be made according to the specific requirements in each individual case.
For dc, the inductance has only the resistance of the wire that comprises the coil, which amounts to a few ohms. Meanwhile, the capacitors still operate as open circuits at dc, so they do not reduce the dc output voltage. However, at the basic ripple frequency of 120 Hz, a 10 Henry inductance has a reactance of:
XL = 2πfL = 7540Ω
At the same time, a 100 µf capacitor at the same ripple frequency has a reactance of:
XC = 1/2πfC = 13.26Ω
Thus, L and C2 form a voltage divider that drastically reduces the ripple component (to less than 0.2%) while leaving the desired dc output nearly alone. This configuration may provide sufficiently pure dc for some applications, without the need for any following regulator at all.
The drawback of this approach is that a 10 Henry inductor is as large as some power transformers, with a heavy iron core. It takes up a lot of space and is relatively expensive. This is why the RC filter circuit may be preferred to the LC filter, provided the ripple reduction is sufficient and the power loss in the resistor is not excessive.