Connect with us

Voltage Regulators

Discussion in 'Electronic Design' started by onyxx, Oct 4, 2005.

Scroll to continue with content
  1. onyxx

    onyxx Guest

    Can anyone tell me how do I find out the maximun and minimun voltages
    needed for a voltage regulator to work properly.
    I have this STR30125 that is suppose to put out a regulated 125Vdc, but
    what is the Vin suppose to be?
    This VR is giving out 83Vdc, which is not correct, but I donn´t know
    if it is recieving the proper voltage, which is 97Vdc.
    I have downloaded the datasheet, but it seems that this VR is very old
    and the datasheet is very short on info...
    Thanks...
     
  2. For any simple voltage regulator (excluding switchers etc.), Vin, must
    always exceed Vout, plus the internal transistor drops. The 30125, is only
    a high voltage regulator, so will require significantly more than 150v in
    to have any hope of working. The drop you have across the regulator seems
    slightly higher than I'd perhaps expect (14v), which may suggest there is
    more current being drawn than there should be.

    Best Wishes
     
  3. "onyxx" <> schreef in bericht
    Can anyone tell me how do I find out the maximun and minimun voltages
    needed for a voltage regulator to work properly.
    I have this STR30125 that is suppose to put out a regulated 125Vdc, but
    what is the Vin suppose to be?
    This VR is giving out 83Vdc, which is not correct, but I donn´t know
    if it is recieving the proper voltage, which is 97Vdc.
    I have downloaded the datasheet, but it seems that this VR is very old
    and the datasheet is very short on info...
    Thanks...

    Saw a datasheet as well. This type has a fixed output voltage of 125V. So
    the input voltage should never become <126.5V, the Vcemin of the transistor.
    For practical purposes I'd take 130V for a minimum. So your input voltage is
    way below what you need.

    petrus bitbyter
     
  4. Ken Moffett

    Ken Moffett Guest

    Data sheet:

    http://pdf.alldatasheet.co.kr/datasheet-pdf/view/86919/SANKEN/STR30125.html
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-