please help with PSU :-((

[tim0 (Timo Christ)]

Hi Duane, 

thanks for the reply.

Duane R Balvage wrote:
<<snip>> my message [-15V Out on my PSU doesn´t work]
>    A-HA! Here is your problem!
> 
>    The filter cap goes BEFORE the regulator, not after. This is why it
> doesn't work.

the filter cap is before the regulator.


> 
>    Your PS *should* look like this:

thanks for the illustration, my PS uses one bridge rectifier for each
output,
so my PS has three.
I have modified your nice ascii-art to show how my PS looks now:

>                                 +-------+       
>                            (+)  |       | 
>   -----) | | (---------+-----+--+      ---
>  mains(  | |  )        | B.R.|  |       - mains ground
>        ) | | (         |     |  |
>       (  | |  ) 18V    |     |  |
>        ) | | (        ++-----+  | 
>       (  | |  )       |   (-)|  +---------+-------+------>
>        ) | | (        |      |            |2200uF |           
>       (  | |  )       |      |           ---      |        0v (out)
>   -----) | | (--------+      |           ---      |          
>                              |            |    +--+---+    
>                              |            |    |      |       
>                              +------------+----+ 7915 +--> -V
>                                                |      |
>                                                +------+
> 
> * B.R. = Bridge Rectifier
> 
>   BTW, the 7915 pinout is a little different - I'm pretty sure the GND
> pin is on the right, and not in the middle...

i got the pinouts right.

please tell me if the design is ok and some part  is defective (reg or
BR) or if there is some terribly stupid idiot-me design error. :-(

thanks for your time,
Timo
-- 
Timo Christ -- Germany -- Europe
root at dist0rter -- tic at vossnet.de -- LEDflash at gmx.net