Particularly LM317 Circuit With 12v Battery Charger Circuit

The LM317 is AN adjustable three terminal transformer that is capable of supply 1.2 to 37 volts with a secure 1.5A output current. The LM317 is prepackaged terribly} normal electronic transistor package that makes it very simple to mount in your circuits.




The LM317 series of adjustable 3-terminal positive voltage regulators is capable of supply in more than 1.5A over a 1.2V to 37V output vary. they're exceptionally simple to use and need solely 2 external resistors to line the output voltage. Further, each line and cargo regulation square measure higher than normal mounted regulators.

In addition to higher performance than mounted regulators, the LM317 series offers full overload protection out there solely in IC's. enclosed on the chip square measure current limit, thermal overload protection and safe space protection.
The LM317 makes AN particularly easy adjustable change regulator, a programmable output regulator, or by connecting a set electrical device between the adjustment pin and output, the LM317 may be used as a preciseness current regulator. provides with electronic conclusion may be achieved by clamping the adjustment terminal to ground that programs the output to one.2V wherever most masses draw very little current.





  • Guaranteed 1% output voltage tolerance (LM317A)
  • Guaranteed max. 0.01%/V line regulation (LM317A)
  • Guaranteed max. 0.3% load regulation (LM117)
  • Guaranteed 1.5A output current
  • Adjustable output down to 1.2V
  • Current limit constant with temperature
  • P + Product Enhancement tested
  • 80 dB ripple rejection
  • Output is short-circuit protected
Output Formula


Once you have learnt enough you can now put the LM317 into use and make the following circuit:

12v Battery Charger Circuit

The circuit may be accustomed charge 12V lead acid batteries.
Pin one of the LM317 IC is that the management pin that is employed to manage the charging voltage, Pin a pair of is that the output at that the charging voltage seems, Pin three is that the input to that the regulated DC offer is given.
The charging voltage and current is controlled by the electronic transistor (Q1), electrical device (R1) and POT (VR1). once the battery is 1st connected to the charging terminals, the present through R1 will increase. This successively will increase the present and voltage from LM317. once the battery is totally charged the charger reduces the charging current and also the battery are charged within the trickle charging mode.

Circuit Diagram



  • The input voltage to the circuit should be a minimum of 3V more than the expected output voltage. luminous flux unit 317 dissipates around 3V throughout its operation. Here I used 18V DC because the input.
  • The charging voltage may be set by victimization the POT (VR1).
  • The luminous flux unit 317 should be mounted on a sink.
  • All capacitors should be rated a minimum of 25V.
  • You'll be able to use crocodilian clips for connecting the battery to the charger.


Source: StreamPowers



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