from the net

[netuddki]

As I said before

Blue or grey smoke?... Let's bet

This extends to AndrewT and peranders

before i turn on the amp, i will call the fire dept!

 

[audioDIYer]

I mean it.

It it works, I'll make one to feed my subwoofer. The pcb is the size of some heatsinks I have.

 

[alex mm]

another PCB for laterals ......

Hi,
Another PCB variant , corrected for laterals http://i34.tinypic.com/t4tkso.gif regards alex mm

 

[black]

very nice out alex mm hope to achieve is someone to tell us how to stay now call av 800 is sure of success

 

[netuddki]

HI!

My lateral ver. with protection diodes!

 

[black]

zener diode protection on the terminal ninus not so good about it links between output and gate MOSFET

 

[netuddki]

 

[audioDIYer]

Smoke?

 

[netuddki]

not yet!

just waiting for the BUZ901P!

The board is ready!

 

[audioDIYer]

Great! Can ou show us a picture of it?

 

[netuddki]

 

[audioDIYer]

toner transfer?
Very good looking.

 

[AndrewT]

and still no sign of the Source resistors

 

[Cal Weldon]

While cleaning up this thread I accidentally erased a post and now it's gone missing. If any of you are missing a post, please let me know and I'll trace it via your name to get it back. Sorry for the inconvenience.

 

[netuddki]

toner transfer?
Very good looking.

NO! I'am using a film!

 

[audioDIYer]

And UV

Now, you need to figure out the best way to put source resistors there... As all transistors will be 'under' the board, maybe you can have some space on the up side...

 

[wakibaki]

Blank laser printer transparencies are becoming hard to get. Everybody uses Powerpoint presentations now. I use the film all the time at work for PCBs. You can use architect's drafting film, but it's expensine.

Better stock up.

w

 

[megajocke]

and still no sign of the Source resistors

I think he has changed his mind and is going to use BUZ901P which are laterals. Then it will work without source resistors.

But why do a quasi complementary lateral design, I can't understand the reason for that...

One of the schematics earlier had some transistors that had the wrong polarity but part number was right. Upper vas transistor was a BC556 but drawn as an NPN for example Watch out!

 

[megajocke]

NO! I'am using a film!

Photographic film?

We have some nice equipment at school for making PCB:s, with a camera similar to this but not as modern:
http://www.photoandi.com/UserFiles/Image/Repro-Camera.jpg

The film we use is negative and the photo-resist is so that it protects copper where it was exposed to light, the film is transparent where you want copper to stay. This means you can put your standard black copper trace layouts in the camera (preferably in 200% size for better printer resolution).

Exposure time is about 30 seconds, both for films in the camera and boards in the double sided UV machine.

There are two huge machines for developing and etching the PCB:s. You start the pump and motor and put in the board on one end of the machine and it comes out the other end, rinsed and everything!!

 

[homemodder]

One of the schematics earlier had some transistors that had the wrong polarity but part number was right. Upper vas transistor was a BC556 but drawn as an NPN for example Watch out!

Mega you might just have saved Netuddki from some blue smoke.