Voltage Regulators

[onyxx]

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...

 

[Roger Hamlett]

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...

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

 

[petrus bitbyter]

"onyxx" <[email protected]> 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

 

[Ken Moffett]

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...

Data sheet:

http://pdf.alldatasheet.co.kr/datasheet-pdf/view/86919/SANKEN/STR30125.html