can I parallel 7812 Chips

PaulHilgeman · 1st May 2003, 05:31 PM

I dont have a need to, but in the event of more needed power, is it possible to parallel 7812 chips to achieve more than 1A of current?

Loading resistors would be used to regulate the load sharing.

-Paul

tiroth · 1st May 2003, 05:41 PM

The usual solution is to drive an external transistor.

PaulHilgeman · 1st May 2003, 05:44 PM

Much better idea!

Thanks

banana · 1st May 2003, 05:44 PM

7812 or other voltage regulators are low output impedance voltage source. Even very tiny output voltage difference between two 7812 chips would lead to a large amount of current flowing between them.

Take a look at the 78XX application note and there are simple methods to increase its current capability. One suggestion would be using bypass transistor.

dhaen · 1st May 2003, 10:19 PM

Hi,

The 78S12 is 2 amp.

Cheers,

Sch3mat1c · 1st May 2003, 10:35 PM

Uhm, you're off by 20 times. The S series are Small, for 100mA or so...in TO-92 cases.

Unless I missed something in the past 5 years...(likely since I'm a toob guy

)

Tim

fdegrove · 1st May 2003, 10:45 PM

Hi Tim,

D'Haen is a toob guy, so are you and so am I...

One thing I know though the S version is good for 2A.

The T version is even good for 3A.

Cheers,

dhaen · 1st May 2003, 10:51 PM

Ah, but the "S" version is TO220

tiroth · 1st May 2003, 10:54 PM

100mA is most commonly 'L'.

Sch3mat1c · 2nd May 2003, 03:32 AM

Ohhhh yeah, that's it, L. My bad.

Tim

1st May 2003, 05:31 PM	#1
PaulHilgeman Account Disabled Join Date: Dec 2002	can I parallel 7812 Chips I dont have a need to, but in the event of more needed power, is it possible to parallel 7812 chips to achieve more than 1A of current? Loading resistors would be used to regulate the load sharing. -Paul

1st May 2003, 05:44 PM	#4
banana diyAudio Member Join Date: Feb 2003 Location: Hong Kong	Never! 7812 or other voltage regulators are low output impedance voltage source. Even very tiny output voltage difference between two 7812 chips would lead to a large amount of current flowing between them. Take a look at the 78XX application note and there are simple methods to increase its current capability. One suggestion would be using bypass transistor.

1st May 2003, 10:35 PM	#6
Sch3mat1c diyAudio Member Join Date: Jan 2003 Location: Milwaukee, WI	Uhm, you're off by 20 times. The S series are Small, for 100mA or so...in TO-92 cases. Unless I missed something in the past 5 years...(likely since I'm a toob guy ) Tim __________________ See my Electronics webpage -- the home of Vacuum Tube Drag Racing. The key to being a successful Audiophile: "I reject your reality and substitute my own!"

1st May 2003, 10:45 PM	#7
fdegrove diyAudio Senior Member Join Date: Aug 2002 Location: Belgium	This Is Funny... Hi Tim, D'Haen is a toob guy, so are you and so am I... One thing I know though the S version is good for 2A. The T version is even good for 3A. Cheers, __________________ Frank

2nd May 2003, 03:32 AM	#10
Sch3mat1c diyAudio Member Join Date: Jan 2003 Location: Milwaukee, WI	Ohhhh yeah, that's it, L. My bad. Tim __________________ See my Electronics webpage -- the home of Vacuum Tube Drag Racing. The key to being a successful Audiophile: "I reject your reality and substitute my own!"


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1st May 2003, 05:41 PM	#2
tiroth diyAudio Member Join Date: Dec 2001 Location: Pittsburgh, PA, USA	The usual solution is to drive an external transistor.

1st May 2003, 10:19 PM	#5
dhaen diyAudio Moderator Emeritus Join Date: Jun 2002 Location: U.K.	Hi, The 78S12 is 2 amp. Cheers,

1st May 2003, 10:51 PM	#8
dhaen diyAudio Moderator Emeritus Join Date: Jun 2002 Location: U.K.	Ah, but the "S" version is TO220

1st May 2003, 10:54 PM	#9
tiroth diyAudio Member Join Date: Dec 2001 Location: Pittsburgh, PA, USA	100mA is most commonly 'L'.

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