HI currenr Regulator

[Williams Audio]

Hi all,
i intend to build a reg with this performances:
Vin=63v +/-7V
Vout= 55v 0.02% of Vout
Iout=12ampre continuously


did some one built it, i think i will help my design with TL-783 from TI
need help wih this
best regards
williams

 

[wakibaki]

63V - 7V = 56V. This is only 1V more than Vo. To design a linear regulator with 55V output and 1V dropout voltage is non-trivial. This really requires a switching regulator.

w

 

[Williams Audio]

well, is really a problem, what is the minimal voltage drop across the pwr transistor in a linear mode, i think 2-3 volts
so i have to change the lower range
Vin= 63V +7V,-4V
in any case thanks for correction
there is any help at the forum?
best regards,
Williams

 

[AP2]

well, is really a problem, what is the minimal voltage drop across the pwr transistor in a linear mode, i think 2-3 volts
so i have to change the lower range
Vin= 63V +7V,-4V
in any case thanks for correction
there is any help at the forum?
best regards,
Williams

Hi,
what type of application requires it? 63V 12A continuous?
normally in this case using smps, or trafo with dc converter or switch rectifier mode.

Regards

 

[wakibaki]

TL783 has 0.15% output voltage regulation for loads 10-50% max output. You want 0.02%. TL783 dropout voltage is 10V. You have 4V headroom. A discrete design will be necessary.

63+7=70V. 70-55=15V. 15V*12A=180Watts worst case dissipation in pass transistor.

I am not saying it is impossible to design a regulator to meet these specs, just very, very difficult, time-consuming and expensive.

w

 

[AndrewT]

Hi,
does the tolerance on input voltage take account of mains supply voltage variations?

If the regulator is designed to properly regulate at the lowest input voltage, then how much power needs to be dissipated when the supply is at the highest input voltage.

Linear is going to be very big and heavy and expensive, if achievable.