Schematic Circuits

LM317 Power Supply

Adjustable power supply using LM317


LM317 power supply


For the LM317:
  • R2 = (192 x VOut) - 240, where R2 in ohms, Vout is in volts and must be at between 1.2 V and 35 V.
  • Vin should be at least 2.5V greater than Vout. Select a wall adapter with a voltage at least 2.5 V greater than your regulated output at full load
  • Maximum output current is 1 A. Use proper heatsink for LM317 if it has to dissipate more than 1W.
  • The tab of the LM317 is connected to the center pin.

Equation for calculating the output voltage when R1 and R2 are known:

Vout = 1.25V * (1 + R2/R1) + Iadj * R2

Where Iadj is typically in the range of 50 microamperes.


Keywords : Power, Circuit, Supply, Schematic, Electronic, Electric, Electricity
Writer : delon  |
14 Jan 2007 Mon   
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