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Title: i neeed equivalent component ............ Post by: satya on February 12, 2010, 03:56:54 03:56 hi
i am working on smps power supply TL431 shunt regulator working up to 37Vdc but i need a shunt voltage regulator working 75Vdc please give the any equivalent part number......... Title: Re: i neeed equivalent component ............ Post by: solutions on February 12, 2010, 04:14:22 04:14 I hope you've done the math Vdrop*I - your power dissipation just doubled....
Check out Supertex Title: Re: i neeed equivalent component ............ Post by: borberk on February 12, 2010, 11:07:14 11:07 Use this:
Title: Re: i neeed equivalent component ............ Post by: tAhm1D on February 12, 2010, 04:33:09 16:33 satya,
You can do it with zener and transistor. For variable ref.,you can add a pot. Title: Re: i neeed equivalent component ............ Post by: PilotPTK on February 13, 2010, 05:15:43 05:15 You can also add a big 40ish V Zeener before the shunt regulator. It will eat the 40 Volts and show only 35 to the Shunt regulator.
As solutions mentioned, make sure you have a part that can dissipate 40V * I = Watts. Running the Shunt Regulator near it's limits also requires watching the VDrop * I for the regulator. You may want to absorb even more in a zeener if the voltage in is relatively stable.. For example 75V -> 70V Zeener -> Shunt Regulator -> 12V That way, you can use a big fat zeener, show only 15V to the Shunt Regulator and only have to drop 3V * I in the shunt. PPtk Title: Re: i neeed equivalent component ............ Post by: satya on February 13, 2010, 05:34:13 05:34 hi
Thank you but i need 75Vshunt regulator ( only single component ) i can not use any equivalent circuit. my pcb is very small no space available for extra components. regards satya Title: Re: i neeed equivalent component ............ Post by: PilotPTK on February 13, 2010, 06:01:17 06:01 Without additional components, I don't think you're going to get what you need. The highest shunt regulator that I know of takes a max of 42V IN.
What is your actual VIN and VOUT requirement? Depending on the drop, something like a floating LM317 might work. PPtk Title: Re: i neeed equivalent component ............ Post by: oldvan on February 13, 2010, 06:32:05 06:32 Perhaps you could use a TL783. Good to 150V input. Pretty much a LM317 on steroids.
http://focus.ti.com/lit/ds/symlink/tl783.pdf http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=296-20687-5-ND A couple bucks US each. |