Regulators in Parallel

[Marvellous]

Is it possible to use regulators in parallel
to increase output current ?

or will this not work?

 

[li_gangyi]

I dun think that will work...coz one regulator will tend to take all the current...and just shut itself down...letting the other take over...and then shutting it down as well...

 

[Bricolo]

you'll have to place a small resistor (0.1 to 2R) between each IC's output and the global output

 

[Marvellous]

So this will WORK

Will I still get 12V output?

 

[li_gangyi]

Possibily...you might want to try tweaking the resistor value to get faster better response...I would try 1ohm first...

 

[Marvellous]

Thanks everybody for the help!😎 😎

I'm going to try this now!

 

[li_gangyi]

By the way...that theory by Albert on relativity was pretty cool....

 

[Vigier]

Heeej Marvellous,

make sure (if you're going to use 1 Ohm resistors, which i DON'T recommend) that these resistors can dissipate enough...

Grtz, Joris

 

[li_gangyi]

I would definetly reccomend a pass transistor if he wants BIG currents...

 

[Vigier]

You MUST use that series resistor or you'll see your 7812's burn one by one, but I would use something between 0.1 and 0.2 Ohm, that should do the job.

Grtz, joris

 

[peranders]

Can you switch to 7812 instead of 78L12?

You can probably connect them brutally in parallel because they have current limitation but they are not indestructable. If you add resistors they will probably share current better but if they don't misbehave without resitors, don't use them.

Switch to 7812 seems to be a better solution if that's possible.

 

[JOE DIRT®]

ummmmm...the series resistor goes on the input

the 78 series regulators have built in current limiting so the resitors on the input act as a current sharing load

and I reccomend a pass transistor also

 

[Bricolo]

I would recommand a bigger reg rather than a pass transistor. Easier to implement

 

[jackinnj]

a pass transistor is cheaper and you don't have to worry about one regulator hogging the current. In fact, you can get a linear regulator to oscillate even without trying. (Nat Semi does have an application note showing the LM317 as a switching regulator!)

In talking to one of the customer service techs at Nat Semi they did indicate that some customers used some of their Simple Switcher Regulators "stacked", but they did not recommend it.

 

[Marvellous]

Pass transistor it is

Then Pass Transistor is is!

I thought that maybe this would be a simple quick Solution!

Thanks AnyWay Everybody 😉 😎