Power Filter- Regulator Circuit With LM1084

My friend want Circuit Filer power supply for Car.
I test is circuit Filer CAR power supply, Use IC LM1084 – 5A Low Dropout Positive Regulators.
It is small circuit and easy to build, Detail more see in image circuit.

I to see web : http://linuxcar.sone.jp/reg.en.html
good idea circuit.
read simple ::
At input side of regulator, I inserted a series inductor in addition to normal decoupling capacitor to form a LC filter, so that it can resist transient voltage. If supply voltage temporary goes up, it can be absorbed by regulator. But if it goes down below 13V, regulator can’t do anything but drops its output voltage. If an inductor is there, it prevents capacitor from discharging into battery side, keeping regulator’s input voltage high. It also prevents noise emission, smoothing the PC’s pulse-ish current consumption.

Additionally, I added a surge suppressor diode (20V) designed especially for car electronics, to protect regulator from higher voltage than its maximum input (30V). Also a DC line filter is inserted just after the input from car, to eliminate high frequency noise.
Schematic diagram of power filter/regulator circuit

The diode between output and input of LM1084 is to protect regulator when supply voltage suddenly drops down and the potential difference becomes reverse. Be sure to choose values of inductor (L) and capacitor (C) at input side so that L/C is small enough. If not, large overshoot/undershoot voltage is caused by load transient. Besides large chemical capacitor, I also put a couple of 0.1ÂµF multi-layer ceramic capacitor near the regulator, to stabilize it against high frequency transient.

Relay is at after the regulator, because controller circuit needs regulated and backed-up power. Because of this, regulator is always connected to the battery. I measured the current with no load, it was 5.2mA. It was more than I expected, but I checked the datasheet and it says 5mA typical. I became a little anxious about the battery, and calculated, then it was less than 1Ah if I leave the car for 1 week. Car battery is 40Ah, 55Ah or something like that, that was no problem, after all.

Low Dropout Positive Regulators 5A with LM1084
Features * Available in 3.3V, 5.0V, 12V and Adjustable Versions * Current Limiting and Thermal Protection Description The LM1084 is a series of low dropout voltage positive regulators with a maximum dropout of 1.5V at 5A of load current. Applications â€¢ Post Regulator for Switch ...
1.2 - 15V 3A adjustable regulated supply by LM1084
This kit provides a variable output power supply ranging from 1.2 to 15 V @ 3 A. It uses Low Dropout Positive Regulator LM1084 in TO220 package for delivering variable output voltage. * Input - 18 VAC/DC * Output - variable output from 1.2 ~ 15 V @ 3 A Regulated low ripple DC ...
Low Pass Filter For FM 88-108 MHz
Filter used for eliminate unwanted harmonic frequency at second and third. Notch filter, Band Pass Filter (BPF), and High Pass Filter (HPF) sometime combined in constructing LPF design. Schematic below for FM Broadcast Lowpass Filter 88-108 MHz. It has been tested with a good result. Note : ...
12 Volt Low Voltage Droput Precision Regulator with LM324
Most regulator circuits require at least 3 to 5 volts between input and output to operate reliably. This regulator features a P-Channel MOS-FET pass element that will allow for a very low drop out voltage. In my particular application reliable operation was noted down to nearly 0.1 volt betwee ...
LH1605 Switching Regulator
The device is housed in a standard 8-pin TO-3 power package containing a temperature compensated voltage reference, an error amplifier, a pulsewidth modulator with programmable operating frequency and a high current output switch and steering diode. Typical performance of the LH1605 is summarize ...