TSSA - The Simplest Symmetrical Amplifier

[Lazy Cat]

Originally Posted by Idefixes

Just a little precision : BJT Bigbt transistors are mounted under pcb "sandwiched" between pcb and heatsink surface by the screw.

Marc

Idefixes, you seriously grip the bull's saddle

Very nice PCB indeed.

Both IRF-s screaming to get in between the outputs, you see their tracks are way too looong.

Also the + and - outputs can be aligned with their pins.

Look down, sch update, just at the right time hehe

[Lazy Cat]

Here's an update with minor connection/parts changes, some values were recalculated.

[Idefixes]

Originally Posted by Lazy Cat

Idefixes, you seriously grip the bull's saddle

Very nice PCB indeed.

Both IRF-s screaming to get in between the outputs, you see their tracks are way too looong.

Also the + and - outputs can be aligned with their pins.

Look down, sch update, just at the right time hehe

I will take care all adwise. I tried with irf between BJT but not found solution in one layer...i will try again to integrate your advises.

Marc

[Idefixes]

next.......

LC, what are this "IR LED". I would be nice if you could communicated me the resistors value change for -/+50Vdc....i am not able to calculate them...

Thanks Marc

[Bigun]

Originally Posted by Lazy Cat

Here's an update with minor connection/parts changes, some values were recalculated.

jeez, this is supposed to be the Simplest ? I think this thread has lost the plot along the way. Pitty, I like really simple.

[Lazy Cat]

Originally Posted by Bigun

jeez, this is supposed to be the Simplest ? I think this thread has lost the plot along the way. Pitty, I like really simple.

Hi Bigun

I can not manage more than two threads simultaneously, so logically one would be full of stuff.

From simple to more complex version, all based on the same TSSA base core. It is the same like in school, gradually progressing the knowledge.

Regards Andrej

[Lazy Cat]

Originally Posted by Idefixes

next.......

LC, what are this "IR LED". I would be nice if you could communicated me the resistors value change for -/+50Vdc....i am not able to calculate them...

Thanks Marc

Hi Marc

Nice PCB improvement.

Attached schematic includes the table of calculated resistor values according to different supply voltages chosen.

IR LED is infrared light emitting diode, high performance one compared to average LED-s.

[Idefixes]

Originally Posted by Lazy Cat

Hi Marc

Nice PCB improvement.

Attached schematic includes the table of calculated resistor values according to different supply voltages choosen.

IR LED is infrared light emitting diode, high performance one compared to average LED-s.

Youpi..that couldn't be better....I continue to work on pcb with some more components alignement and some mistake (0.22r 5W package) corrections.
On my version i put in the possibility to bypass the TLP627 since you have your own systeme to drive this unit -power management unit...if i remember-

Marc

[Idefixes]

Originally Posted by Lazy Cat

IR LED is infrared light emitting diode, high performance one compared to average LED-s.

Something like this : Product Folder - QED123 - Plastic Infrared Light Emitting Diode, Fairchild Semiconductor?

Marc

[Lazy Cat]

Mostly any 5 mm IR LED is okay.

At current If=3,5 mA, forward IR LED voltage is app. 1,2 V and that is too low for proper cascode, so please provide two of them in series on the PCB. That will provide Vce=1,8V for VAS BC transistor.

P.S. 2SA/2SC transistors needs on PCB 5-10°K/W heatsink, since they dissipate app. 0,7 W each at 75 V supply voltage.