I need 15 volts regulator from 40 volts DC

sunny · 3rd May 2011, 04:31 PM

I need 15volts dual power supply for my TL072 subwoofer preamplifier. I'm getting around +38 ,0,-38v volts DC from my power amplifier. I have one option to use 7815 regulator but i think it's maximum voltage is only 35 volts.So is there any other regulator like 7815 that can withstand input voltage upto 40 volts DC?
Please help.

Thanks,
Sunny

sofaspud · 3rd May 2011, 04:37 PM

The LM317 and LM337 are what you're looking for.

sunny · 3rd May 2011, 04:40 PM

I need fixed 15 volts voltage regulator just like 7815 and 7915.
Please help.

Sunny.

sofaspud · 3rd May 2011, 04:48 PM

So "fix" the LM317 and LM337 at +15 & -15.
Or lower the 38V using the LM317/LM337, then use your precious 7815/7915.

leadbelly · 3rd May 2011, 05:00 PM

Tilting at windmills - Wikipedia, the free encyclopedia

sunny · 3rd May 2011, 05:02 PM

Quote:

Originally Posted by sofaspud

So "fix" the LM317 and LM337 at +15 & -15.
Or lower the 38V using the LM317/LM337, then use your precious 7815/7915.

Can you please give me the circuit diagram how to fix the LM317 and LM337 at +15 & -15?

Thanks,
Sunny

sofaspud · 3rd May 2011, 05:27 PM

Quote:

Can you please give me the circuit diagram how to fix the LM317 and LM337 at +15 & -15?

I don't have a diagram handy to upload, but you can find one easy enough in the datasheets or online. The resistors to set 15V are 220 ohms from the output to adjust pin and 2400 ohms from the adjust pin to ground.

JayBe · 31st May 2011, 05:46 PM

I have the same question. 38v to 15v is a big step down. That's the reason I wodnt't try the 317/337 regs. I think they could overheat and blow easy, even with heatsink.

Mooly · 31st May 2011, 05:51 PM

If you only want to run an opamp or two then a simple resistor/zener regulator is a good option.

Andy5112405 · 31st May 2011, 06:00 PM

Quote:

Originally Posted by sunny

Can you please give me the circuit diagram how to fix the LM317 and LM337 at +15 & -15?

Thanks,
Sunny

Please try looking at the LM317 datasheet.

3rd May 2011, 04:31 PM	#1
sunny diyAudio Member Join Date: Oct 2004	I need 15 volts regulator from 40 volts DC I need 15volts dual power supply for my TL072 subwoofer preamplifier. I'm getting around +38 ,0,-38v volts DC from my power amplifier. I have one option to use 7815 regulator but i think it's maximum voltage is only 35 volts.So is there any other regulator like 7815 that can withstand input voltage upto 40 volts DC? Please help. Thanks, Sunny

3rd May 2011, 04:37 PM	#2
sofaspud diyAudio Member Join Date: Nov 2005 Location: San Antonio TX	The LM317 and LM337 are what you're looking for. __________________ It is error only, and not truth, that shrinks from enquiry. - Thomas Paine

3rd May 2011, 04:48 PM	#4
sofaspud diyAudio Member Join Date: Nov 2005 Location: San Antonio TX	So "fix" the LM317 and LM337 at +15 & -15. Or lower the 38V using the LM317/LM337, then use your precious 7815/7915. __________________ It is error only, and not truth, that shrinks from enquiry. - Thomas Paine

3rd May 2011, 05:00 PM	#5
leadbelly diyAudio Member Join Date: Dec 2002 Location: Calgary, Alberta	Tilting at windmills - Wikipedia, the free encyclopedia __________________ Aerodynamics are for people who can't build engines. Enzo Ferrari

31st May 2011, 05:51 PM	#9
Mooly diyAudio Member Join Date: Sep 2007	If you only want to run an opamp or two then a simple resistor/zener regulator is a good option. __________________ ------------------------------------------------------- *A simulation free zone.* *Design it, build it, test it.*


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3rd May 2011, 04:40 PM	#3
sunny diyAudio Member Join Date: Oct 2004	I need fixed 15 volts voltage regulator just like 7815 and 7915. Please help. Sunny.

31st May 2011, 05:46 PM	#8
JayBe diyAudio Member Join Date: May 2011	I have the same question. 38v to 15v is a big step down. That's the reason I wodnt't try the 317/337 regs. I think they could overheat and blow easy, even with heatsink.

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