Small Electronic Project

PerrinV2

(Not sure if this if the right forum to be posting in but...)Hello all,I'm working on a small electronic circuit myself here ---->>>
http://www.elektor.com/magazines/2008/july-047-august/dtmf-controlled-home-appliance-switcher.531629.lynkx

Just wondering would anyone know the pin outputs of B1 and B2?
As in +,-,~ and ~ ????
Any help would be appreciated,things haven't gone well so far...

x in the city

that pcb is uselsss, send on a pdf of the pcb so someone can see it properly.

its a bridge rectifier i assume...?

so it should be easy enough to match up the polarity of the diodes.

FarmerGreen

Spec sheeet for the bridge rec
http://www.wontop.com/pdf/BC1500.pdf
The + pin is longer, its at the top when the writing is horizontal, and its marked with a +.

The B2 bridge +ve is connected to R2, so the + pins would be bottom left on both.

steifanc

the two squiggles " i cant find that key do i have one ??"

is the ac in , unpolarized ,

+ - is the dc out polarized

PerrinV2

Just also I'm thinkin component T1:BD139 looking directly down on the board I think it placed pin 1 first,then pin 2 then pin 3

And also does it matter which way the boxheaders go in as long as pin 1 on the board and the pin1 on the boxheader match up?

FarmerGreen

BD139 datasheet http://www.datasheetcatalog.org/datasheet/fairchild/BD139.pdf
Looks like he used the wrong footprint for the device.
Looking at the PCB with the writing normal way round
Top hole - R3 - Collector
Mid hole - R4 - Base
Bottom hole - ?- Emitter

BD139 pinout is E C B from the left (metal tab at the back)

Middle pin - Top hole
Left pin - Bottom hole
Other pin - last hole

Headers, shortest pins go in the board, also, some of them have small
bumps on the board side to prevent moisture wicking between the pins.

PerrinV2

That bd139 is gonna be a nightmare to put in now so....

FarmerGreen

Like this?

PerrinV2

No I mean in the sense that with the wrong footprint on the board the pins are too big on the bd139 to fit into the holes.

FarmerGreen

Oh right, how about E to mid pin IC3, B to leg of R4, C to leg of R3
On the component side.

PerrinV2

I don't think E will reach IC3,but does it have to go there? there's no track on the board sayin its connecting to anything

FarmerGreen

Its a double sided board and they are only showing you the component side tracking
There should be a track on the other side (track side), named 'GND' on the circuit diagram.