Soft Start for PSU


Posted on Apr 30, 2012

Two soft start power supplies. The output voltage slowly increases to the desired output. The output voltage rises slowly and reaches 15 V in 5 seconds. In order to perform this soft-start function, the LM317 voltage regulator IC requires an external universal PNP transistor and the L200 uses its internal comparator (pin 2).


Soft Start for PSU
Click here to download the full size of the above Circuit.

After switch-on, the rising voltage on the positive side of the charging electrolytic capacitor slowly turns the (initially conducting) transistor off, thus raising the voltage (relative to ground) on the adjustment pin of the LM317. In the L200 circuit,




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Radio Control Motor speed Interface
    TBA810 - 7 Watt Audio Amplifier Circuit
    No-bias L-C High-Frequency Oscillator
    Ultrasound Sensor
    s1d13700 arduino documentation
    Remote Control Server RCS
    20dB VHF Amplifiers
    Amateur Radio circuits
    2 transistor buffer
    Test Instruments
    Coop automatic controller circuit diagram
    Electric shaver motor drive circuit



    Top