LM317 variable voltage regulator to output 3.3 Volts. A handy circuit to power arduino or pinguino modules which require 3.3 volts. I created a simple circuit using the LM317 to output 3.3 volts from a 5V or greater input voltage. Why? Because, a number of modules for the Arduino (or Pinguino) take LM138 / LM338 5 Amp 3-Terminal Adjustable Regulator Datasheet - (PDF 400kB) - May 1998 Figure 4: 50mA Constant Current Battery Charger Schematic for LM317. Voltage Regulator Links. The Care and Feeding of LM317 and LR8 Integrated Circuit Regulators, Particularly in Valve Circuits. We use a dc voltage regulator number LM317T is the heart of the circuit. Suggestion of the printed circuit board to assemble the Eliminator Batteries for 1.5, 3, 4.5, 5, 6 and 9 Volt. Working of LM317 Voltage Regulator Circuit. This voltage regulator circuit is very simple. The capacitor C1 used for the filtering of DC input voltage and further fed to the Vin pin of the LM317 voltage regulator IC. The adjustable pin is connected with the two external resistor, and connected Constant current source circuits with a LM317 variable voltage regulator. Also see LM317 High Power Constant Current Source Circuit. A constant current source (CCS) in electronics is a device/circuit that produces a constant value of current regardless of source voltage or load LM317 Voltage Regulator Pinout. [Click the image to enlarge it]. When it comes to variable voltage regulation requirements LM317 would most likely be the first choice. Apart from using it as a variable voltage regulator, it can also be used as a fixed voltage regulator, current limiter, Battery charger As you looked through the datasheet, the simplest circuit we can have to make this guy work, the circuit picture is atacched, We will use I had picked up a LM317 to use as a voltage regulator for my breadboard but never got around to set it up. Thanks for the tutorial. The simulation compares two LM317 voltage regulators. The first one is CL's LM317 with the default parameters, the second is a LM317 with "optimized" parameters picked from a "real" circuit and from TI's data sheet (the data sheet has min, typical and max values, that's not always easy to decide). Some assorted useful lm317 application circuits from National Semiconductor pdf datasheet has been discretely explained in this chapter through the relevant circuit illustrations. The compilation includes configurations like 5A Constant Voltage / Constant Current Regulator, 1.2V to 35V Regulator with The popular LM317 voltage regulator IC is designed to deliver not more than 1.5 amps, however by adding an outboard current boost transistor to the circuit it becomes possible to upgrade the regulator circuit to handle much higher currents, and upto any desired levels. The LM317 Voltage Regulator is a 3-terminal adjustable voltage regulator which can supply an output voltage adjustable from 1.2V to 37V. It can supply more than 1.5A of load current to a load. LM317 Pinout LM317 Schematic Diagram LM317 Circuit LM317 Datasheet.