SE Electronics Z3300a

[Emmathom]

Plan E
replace the 4.7v zener with a 6.2v one

and so on if it doesn't fit (6,8 / 7,5 / 8,2...)

 

[micolas]

and so on if it doesn't fit (6,8 / 7,5 / 8,2...)

Correct!

 

[micolas]

D2 17,20v
looks like we're standing still...

how many plans have we got... ?

the voltage of zener D2 will remain the same

 

[Emmathom]

28,57 / 58,10 with z6,4v (measured)
will up to 7,5v (or 8,2v ?)

 

[micolas]

28,57 / 58,10 with z6,4v (measured)
will up to 7,5v (or 8,2v ?)

9,1v

 

[micolas]

28,57 / 58,10 with z6,4v (measured)
will up to 7,5v (or 8,2v ?)

when we reduce R5, the dc/dc voltages will also decrease

 

[Emmathom]

28,83v / 58,61 (z9,1v)

 

[micolas]

28,83v / 58,61 (z9,1v)

Z 12v

 

[Emmathom]

28,76v / 58,60v (z12v)

this circuit is soooo hard to bias !

 

[micolas]

28,76v / 58,60v (z12v)

this circuit is soooo hard to bias !

A big contribution to the differences in dc/dc are:
1. the inductors/electromagnetic coupling, the dispersion of jFET and BJT parameters
2. the tolerances of the other components.
*
Very random selection,
QC almost non-existent.
*How the f**k do you make a matched pair???

 

[Emmathom]

z12v has not increase our voltage regarding to 9,1v...

 

[micolas]

z12v has not increase our voltage regarding to 9,1v...

plan F
we reduce the value of R13 with a VR 100k above it in parallel
Zenners stay that way

 

[Emmathom]

It's getting more & more intersting
Frankest.bone !
now I must measure the VR value (it's gonna be... let's say 15KΩ or so I guess)

 

[micolas]

It's getting more & more intersting
Frankest.bone !
now I must measure the VR value (it's gonna be... let's say 15KΩ or so I guess)

measures voltage polarization and voltage after R5

 

[Emmathom]

Polar +60,04 & -60,04 / after R5 20,56 / Fet D 15,87

Do I reduce ploar to 57v as the Orig-mod ?

 

[micolas]

Polar +60,04 & -60,04 / after R5 20,56 / Fet D 15,87

Adjust R13 via VR to get Upolariz=62..63v
When we adjust R5, Upolariz will decrease

 

[micolas]

It's getting more & more intersting
Frankest.bone !

It's already starting to sound DIY

 

[Emmathom]

61,8v can't go further > RV must be at 0,01Ω so for 60v I was certainly aroud a few hundreds of Ω

 

[micolas]

61,8v can't go further > RV must be at 0,01Ω so for 60v I was certainly aroud a few hundreds of Ω

OK
put over R13 a 6.8k in paralel
and measure
Upolarize
U AfterR5

 

[Emmathom]

Time is running when concentrated on electronics... almost 20h and I must get back to my family life...
Ok I'll put 6,8KΩ in place of 27KΩ tomorrow...
Thanks a lot for all your support Micoals, I will be back 'morrow