lm317 3.3 v schematic diagram

lm317 3.3 v schematic diagram

The more expensive LM117 uses a 240 ohm resistor for R1. The LM317 is supposed to use a 120 om resistor or less so that its output voltage doesn't rise without a load if it has its max rated operating current and if its input voltage is high.




With 120 ohms for R1 and 360 ohms for R2 the output is 5.0V.

with 120 ohms for R1 and 200 ohms for R2 the output voltage is 3.333V.

These resistors are common 5% values.

2n3055 voltage regulator

2n3055 voltage regulator
Variable Voltage Regulator 0-28V at 20A with LM317 and 2N3055
This is Variable Voltage Regulator 0-28V Size at 20A high current. By use IC LM317 be the control part Volt with VR1. The transistor 2N3055 x 5 amounts are wasp parallel. For help have current tall go up be 20A originally from at IC LM317 can give current get 1.5Amax only just. The detail is other. Please read at site source.

voltage regulator lm7805

Voltage Regulator (regulator), usually having three legs, converts varying input voltage and produces a constant regulated output voltage. They are available in a variety of outputs.


The most common part numbers start with the numbers 78 or 79 and finish with two digits indicating the output voltage. The number 78 represents positive voltage and 79 negative one. The 78XX series of voltage regulators are designed for positive input. And the 79XX series is designed for negative input.

Examples:

· 5V DC Regulator Name: LM7805 or MC7805

· -5V DC Regulator Name: LM7905 or MC7905

· 6V DC Regulator Name: LM7806 or MC7806

· -9V DC Regulator Name: LM7909 or MC7909

The LM78XX series typically has the ability to drive current up to 1A. For application requirements up to 150mA, 78LXX can be used. As mentioned above, the component has three legs: Input leg which can hold up to 36VDC Common leg (GND) and an output leg with the regulator's voltage. For maximum voltage regulation, adding a capacitor in parallel between the common leg and the output is usually recommended. Typically a 0.1MF capacitor is used. This eliminates any high frequency AC voltage that could otherwise combine with the output voltage. See below circuit diagram which represents a typical use of a voltage regulator.
 
 
 

Note:

As a general rule the input voltage should be limited to 2 to 3 volts above the output voltage. The LM78XX series can handle up to 36 volts input, be advised that the power difference between the input and output appears as heat. If the input voltage is unnecessarily high, the regulator will overheat. Unless sufficient heat dissipation is provided through heat sinking, the regulator will shut down.
source : http://www.eidusa.com/Electronics_Voltage_Regulator.htm

regulator lm317

regulator lm317

Description:


I constructed this voltage regulator to power my two way mobile radio from the car cigarette lighter circuit. It has many other uses and the voltage can easily be adjusted by the use of a potentiometer. The voltage regulator is an LM317T, and should accept up to about 14 volts without problems. It can handle up to 1 amp, but you WILL need a heatsink on the voltage regulator.

The components :

R1= 270R

R2=2K Cermet or carbon preset potentiometer

C1=100nF

C2=1uF tantalum

LM317T Voltage regulator

Heatsink

PCB board



I also added DC power jacks for input and output on my voltage regulator, a green power LED, and a red over-voltage LED. The over voltage LED uses a zener diode to switch on the LED at a certain preset voltage, this can be varied depending on the voltage of the zener diode, I used a 6.2v zener diode. If you plan to vary the voltage for the different items you power, don't bother adding this feature. If you only plan to use items that run on one voltage, this is a very useful feature and will save plugging in and damaging your valuable (or not so valuable) equipment. You can even add a relay to switch off the power if the over voltage LED turns on, but bear in mind it will have to work from the voltage of the zener diode right up to the input voltage. I couldn't add a relay because I couldn't find any that operated from 6.2-13.8 volts. Anyway, the schematic is shown above, the over voltage and power LED are not included in them because it is assumed that anybody who makes this will understand how to use a zener diode

voltage regulator using zener diode

voltage regulator using zener diode

9V Regulator low current Supply

mini power supply regulator give friends try out again. Be fixed voltage regulator 9V size. It uses transistor be pillar equipment perform boost up current tallly go up about 300mA. And by have Zener Diode perform steady voltage at 9Vdc. The detail is other a friend sees in the circuit please yes



http://www.elecfree.com/electronic/9v-regulator-low-current-supply/