Dear Rolando,
High voltages in a preamp are a low cost technique to obtain high linearity
at 2V output level with few transistors... because 75V is enough for 25VRMS...
And because you have only one secondary and rectifier for the 110V output too, here is the need for a 150V at the rectifier output.
For 75V regulator, 90V input is more than adequate.
About power consumption in this circuit, you need only 31.1 mA @ 75V.
(4.5mA for 20V, 23.2mA for 75V and 3.4mA for the 75V zener).
This manner, 31.1mA x 150V= 4.665W
for the trafo, (110+110V) x 100mA = 22W, Which is good enough.
Regards,
Marcos
High voltages in a preamp are a low cost technique to obtain high linearity
at 2V output level with few transistors... because 75V is enough for 25VRMS...
And because you have only one secondary and rectifier for the 110V output too, here is the need for a 150V at the rectifier output.
For 75V regulator, 90V input is more than adequate.
About power consumption in this circuit, you need only 31.1 mA @ 75V.
(4.5mA for 20V, 23.2mA for 75V and 3.4mA for the 75V zener).
This manner, 31.1mA x 150V= 4.665W
for the trafo, (110+110V) x 100mA = 22W, Which is good enough.
Regards,
Marcos
Hi Marcos
Thanks for the advice, information gives me the peace I need to order the transformer, which I think should be made to order. In Buenos Aires there are many people who do, but Alamtec is specialized in manufacturing and selling certain prestige, I have sent a mail asking budget.
I have also requested a trading model have already done, which may lower the cost. I think there is no problem in putting together the ends of the secondary to be the midpoint, but are physically separated electrically guess they have to work well.
Maybe so? Or not advisable?
As always very gentle, Mark, thank you very much!
Rolando
ALAMTEC | La Casa del Transformador :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::...
TRA-2236
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Hi Rolando,
in this case, you need only one transformer (TRA2236). Just use a bridge (4 diodes) instead of 2 diodes.
50VA of one tranformer is more than enough.
regards,
Marcos
in this case, you need only one transformer (TRA2236). Just use a bridge (4 diodes) instead of 2 diodes.
50VA of one tranformer is more than enough.
regards,
Marcos
Well, that solution obviously is best, rectification bridge without midpoint!
" Four eyes are better than two" 😉
Regards Marcos !
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