F5 Turbo Circuit Boards

[UKToecutter]

OK fellas.
I've tried to take on board all your comments.
Please see revised layout.
Board is now 300mm x 50mm

[Bksabath]

Originally Posted by UKToecutter

OK fellas.
I've tried to take on board all your comments.
Please see revised layout.
Board is now 300mm x 50mm

IMO traks to long and different lenghts

can you (I mean I would) first place trak for speaker output on one side of board (pins don't have to line up can be bent back or forward a bit.

That would be the track you ear and the one carring signal 3 mm maybe more (the more the better)
then do the rest working over that.

Work on one side first and mirror on other side (+ and - )

If you ask nicely Zen (we all love him realy) is realy quik in posting nice picies of Papa lay out (mind bogling simple and elegant).

Another dumb question How much heath came out of the Diodes?

Maybe litle sinks for those do

[UKToecutter]

I'm not sure I understand what you're saying.
The output is on the top of the board between Q4 & Q6 presented on a two position Phoenix connector (Bear in mind this is just one channel).
The input is on the bottom of the board.
I appreciate what you're saying regarding track lengths but I am keen to to get plenty of seperation between the output devices to spread heat along the whole length of the heatsink (that's why tracks are long). Dissipation is what I'm after.
The Diodes are on the board edge in order that they can be mounted on the heatsink.

Andy

[Bksabath]

Sorry at work so I have to describe

Keeping all your mosfets as they are on top of picture as we are looking at it.

Draw the track going to the speaker as a straight line connecting the 4 drains

Once you got that do the rest.

The positive and negative suply conect more or less the same pins on the 2 separte side of board.

Draw one side then copy/ mirror to other

[chchyong89]

Originally Posted by bobodioulasso

No need of a speaker return on the pcb. Can be wired at main star ground, leaving input ground clean.
At least separate ouptut ground path from input ground path.


look at current flowing through R7, R8, R3 when output is near positive rail.

I still don't get you, sorry for bothering you. I know the speaker output ground will return to the common ground at point A as stated. But still, i still don't understand why you mention that the signal ground and decoupling ground cannot end at the middle ground on the PCB before connecting to point A. Maybe my english understanding is a bit poor that i have misunderstood you.

See if the following attachment correct:

[bobodioulasso]

Sorry, i was mixing a bit with Uktoecutter layout.

What i mean is: it is preferable to choose a star point on the pcb and return decoupling caps their own way.
On your, input resistors return and decoupling caps return use a common path.
But maybe i am splitting hairs into pieces as the path is so short and trace is doubled.

Your understandig is certainly better than my english.

[UKToecutter]

bksabath

OK, taken on board your comments and I've tried to make as symmetrical as possible.
A bit awkward with the long thin board but hey, never mind.



Andy

[Bksabath]

Hi Andy

Well now the most important track is well sorted.

Don't you think ?

I have one tought regarding the source diodes.

They only conduct when current get up so V drop across the resistor increase over a certan limit could those do better on theyr own litle sinks?.

I will try your aproach and then the other way.

[Bksabath]

Kroompst
I was doing nicely with the board and program crashed.
Silly me no saves for jonks.
If sometink is bound to happen it will strive to happen as soon as possible.
So got to start againg.

Tanks 6L6 yes they do question is how much and how often.
How often is how often current demand get above the point at which V drop across sources get up to certain point so not much while amp idle.

[Bksabath]

Here is the first one.
There is a lot to tidy up and I would stager the pins of Mosfets and Diodes so to save corners on the tracks like on sketch.

Just for the record I am not saing that is beter or worst than any Is just my way to pluck a Duck (I like cats so there you have it)