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6A PSU using L200

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Bluechip:

--- Quote from: Stilldrillin on July 30, 2010, 12:34:54 PM ---
--- Quote from: Bluechip on July 30, 2010, 10:49:29 AM ---
EDIT   .. BTW, your pic seems to be minus the little triangle thingy that makes it whizz round ...  :thumbup:  any chance ?


--- End quote ---

I`m confused again Dave.......  ::)

Why would the pic need to whizz round?  :scratch:

If you mean the crank throw. It`s still there......... It all gets a little blurred at a dizzy 400+ rpm!  :)



David D

--- End quote ---

Those funny pics. with 'YouTube' in the botom RH corner, and a grey rectangle with a black triangle in the centre ...

Sort of shorter version of the Saturday Afternoon 'Tuppenny Rush' ..

No Candy Floss tho'  :scratch:

Dave BC

Bluechip:

--- Quote from: John Swift on July 30, 2010, 12:15:44 PM ---Yes your right     I've saved a smaller picture
the first picture did not look that big when I saved  :hammer:

would one mje2955   ( plastic pnp) not of been ok ? or even a 2N3055 ( metal npn )

I've not used the L 200 regulator my self  - thats why I am following your project

waiting for your next instalment



--- End quote ---

John

You could use a ( or more ) MJE2955, but not a 2N3055. Needs to be pnp, not npn.

On this PSU input volts is about 10V, lowest output Volts is 2.7-ish. This gives about 7.3 volts across each transistor x ( 3A )... ie some 22W.

With one it's 44W ... I used two MJ2955's to give them an easier time .. I got quite a few anyway. Will also put a box fan on it.

If you download the L200 .pdf and also the L200 Application Notes ( more circuits ), from ST.com it's all in there .. :thumbup:

Would post the .pdf of the Eagle Schematic but I don't know how to  :scratch:

Don't even know how to post a image ... tried but failed ....  :hammer:

Dave BC
 

Stilldrillin:

--- Quote from: Bluechip on July 30, 2010, 12:56:05 PM ---
Those funny pics. with 'YouTube' in the botom RH corner, and a grey rectangle with a black triangle in the centre ...

Sort of shorter version of the Saturday Afternoon 'Tuppenny Rush' ..

No Candy Floss tho'  :scratch:

Dave BC

--- End quote ---

Oh..... Them things!  :doh:

I get bored wi em, after a few seconds of watching an engine whizzing. So, I only take filums of new stock.  ::)


Drive a candy floss machine!  :bugeye: Oh yeah..... That's a great idea!  :D



Anyhow....... I think we should return to topic.  :thumbup:

Whatever it was .......  :scratch:

David D

Bluechip:
Topic ????   Wot topic ... Choccy bar ??

Nowt to do wi me anyway    :lol:  :lol:

Gone 

John Swift:
Hi Dave BC ,
 I see you had two good reasons for using the MJE2955's
first you have them all ready and the pin out of the IC makes it easier to use a pnp transistors

you would need to use a pnp transistor with a npn power transistor like the 2N3055 to form a quasi -pnp transistor
like they used to do in audio amplifiers when there was not as many PNP power transistors

the first IC regulator I used was a uA723 , ideal for using with NPN transistors
Its a bit old ( like me ) but because the reference voltage came out of one of the pins and both op amp/ error amplifier  inputs , it was easy to turn the output down to zero

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