LM3X7 Supply

[AndrewT]

I wish you would change C3 & C4 to 100nF.

 

[audiosteve]

Gordy Wrote:

Your R3 and R4 are OK.

Your D8 is wrong direction. Important !
Refer to http://cache.national.com/ds/LM/LM337.pdf , Page 6.



This didn't make sense so I looked at the doc and don't see any problem with the D8 orientation as is.
You might want to double check this to be sure.

 

[AndrewT]

Hi,
the diodes in post 15 are OK.
But I cannot read the PCB (blue on black) well enough to check if the PCB matches the schematic.
I too think that the PCB shows R3 & R4 are connected to sense ground.

 

[paulebappie]

I was looking for the optimal LM317 PSU and found one.

Change C3 & C4 to 100nf and close to the regulator as Andrew suggested.

Put a resistor of 1.1 to 2.2 ohm 5W between C1 > C9 and C2 > C10 to reduce ripple even more.

C5 & C6 10uF
C7 & C8 10uF tantaal
and a diode at each output (parallel to C7 & C8)

 

[Gordy]

Gordy Wrote:

Your R3 and R4 are OK.

Your D8 is wrong direction. Important !
Refer to http://cache.national.com/ds/LM/LM337.pdf , Page 6.


This didn't make sense so I looked at the doc and don't see any problem with the D8 orientation as is.
You might want to double check this to be sure.

D8 was wrong. I noted that. Zei then read my note. Zei then changed D8 in the diagram to correct it. Zei then noted:

Thanx for that sharp eye Gordy !!
Fixed it.

/Z

So all is well in diode world.
Have a nice day.

 

[zei]

Hi All!

Changed C3, C4 to 100nF

And you where right about R3, R4. They where touching ground.
Don no how i missed that so thanx.

I,ll upload fixed sch and layout shortly.


HAPPY HOLIDAYS!!

Thanx for all support.

/Z