A question about LM7812 (Regulator)

badboy6120 · 5th September 2011, 07:06 AM

Hi guys

I have a question about this LM7812 regulator
Can I use several of this regulator(3 of them) with the same DC voltage? ( To power different circuits)

wintermute · 5th September 2011, 11:25 AM

Hi Badboy, Just want to clarify what you mean. Do you mean one input DC voltage (say 15V) feeding to three separate LM7812's which power different circuits?

If that's the case it should be fine provided the input has enough current capacity to power all three circuits. You may also need to pay some extra attention to grounding.

Tony.

badboy6120 · 5th September 2011, 03:20 PM

Quote:

Hi Badboy, Just want to clarify what you mean. Do you mean one input DC voltage (say 15V) feeding to three separate LM7812's which power different circuits?

If that's the case it should be fine provided the input has enough current capacity to power all three circuits. You may also need to pay some extra attention to grounding.

Hi wintermute
thank your your reply
yes, that's exactly what I meant
Are you sure about this(you've tried this before) or you guess that's gonna be O.K??
and also could you give me some information about "the grounding" thing ( what do I have to do? doesn't they have the same ground that I should connect them to ground of DC supply??)

! · 5th September 2011, 08:51 PM

^ There are plenty of electronic devices using more than one regulator from the same supply rails. Yes it will be ok.

When the regulator outputs a voltage it is in reference to (0V) ground where that regulator is. Thus if powering a remotely located circuit where good regulation is important (in many circuits it isn't) you may want to use a ground return to the regulator or star ground, not a ground traces that passes by other regulators or subcircuits using significant current.

wintermute · 6th September 2011, 09:54 AM

Hi Badboy no I haven't tried it myself but I've certainly seen circuits that do have multiple reg's

What ! said with respect to sharing ground connection where significant currents may be present was what I was alluding to with the paying extra attention to grounding comment.

Any benefit of muliple reg's could be undone if the grounding is not right.

Tony.

badboy6120 · 6th September 2011, 10:13 AM

Thank you all for your replies
really helped

5th September 2011, 07:06 AM	#1
badboy6120 diyAudio Member Join Date: Feb 2011 Location: Malaysia	A question about LM7812 (Regulator) Hi guys I have a question about this LM7812 regulator Can I use several of this regulator(3 of them) with the same DC voltage? ( To power different circuits)

5th September 2011, 11:25 AM	#2
wintermute just another diyAudio Moderator Join Date: Aug 2003 Location: Sydney Blog Entries: 22	Hi Badboy, Just want to clarify what you mean. Do you mean one input DC voltage (say 15V) feeding to three separate LM7812's which power different circuits? If that's the case it should be fine provided the input has enough current capacity to power all three circuits. You may also need to pay some extra attention to grounding. Tony. __________________ Any intelligence I may appear to have is purely artificial! Some of my photos

6th September 2011, 09:54 AM	#5
wintermute just another diyAudio Moderator Join Date: Aug 2003 Location: Sydney Blog Entries: 22	Hi Badboy no I haven't tried it myself but I've certainly seen circuits that do have multiple reg's What ! said with respect to sharing ground connection where significant currents may be present was what I was alluding to with the paying extra attention to grounding comment. Any benefit of muliple reg's could be undone if the grounding is not right. Tony. __________________ Any intelligence I may appear to have is purely artificial! Some of my photos

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
FFT Noise Spectrum of the LM7812 three terminal fixed voltage regulator	rjm	Power Supplies	7	24th December 2009 03:59 PM
LM7812 Test, PSRR 60dB at 100Hz ripple	lineup	Power Supplies	7	6th November 2006 02:12 AM
lm7812-22v/2A in?	reever	Parts	4	21st April 2005 12:20 PM
Lm7812/7912	kinser	Chip Amps	9	22nd November 2004 09:55 AM
regulator question	fezz	Parts	12	16th April 2003 03:10 PM


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

5th September 2011, 08:51 PM	#4
! diyAudio Member Join Date: Jun 2005 Location: Midwest	^ There are plenty of electronic devices using more than one regulator from the same supply rails. Yes it will be ok. When the regulator outputs a voltage it is in reference to (0V) ground where that regulator is. Thus if powering a remotely located circuit where good regulation is important (in many circuits it isn't) you may want to use a ground return to the regulator or star ground, not a ground traces that passes by other regulators or subcircuits using significant current.

6th September 2011, 10:13 AM	#6
badboy6120 diyAudio Member Join Date: Feb 2011 Location: Malaysia	Thank you all for your replies really helped

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read