power supply problem (no -15) ***SOLVED***

what could I wrongly done?
there is 0V on minus 15
+15 and +5 are ok

polarization on diodes, el.caps etc checked, all ok
on other side of D2 is +0.07V

also every time I plug charger to the Power Jack
there is spark between plug and Jack

D2 dead?

any idea?

I think I bought wrong charger 15V DC
It should be transformer 15V AC
is above correct?
logically thinking yes
how on earth you can get negative voltage from +15 DC
hmmm

Yes, you need an AC powersupply instead of DC.

yep
thanks mate

No problem, have fun during your build!

I just connected 15V AC Transformer

+5.1 ok
+14.7 ok
but
-17.3 ??!! thats out of tolerance, isn't it?

is it possible that by connecting previously (by mistake) DC power adaptor instead of AC Transformer
I damaged Negative Voltage Regulator IC5 (7915) ?
or some other component?

Your power section works perfectly now. Negative regulator needs a little load to start working.
You can put like 2,1k resistor there and then measure.

juicyboy wrote:You can put like 2,1k resistor there and then measure.

I checked with 3.3k between 0 and minus

Reading is now -15.00

Thanks juicyboy for this tip

tomektowski wrote:
juicyboy wrote:You can put like 2,1k resistor there and then measure.
I checked with 3.3k between 0 and minus

Reading is now -15.00

Thanks juicyboy for this tip

No problem. I asked this same question when I first started building

@ tomektowski - where did you buy that power supply?