A
Andre Majorel
- Jan 1, 1970
- 0
I think that you could use a 2 x 15V transformer for a +/-15V
linear PSU. The LM317 and LM337 need Vin to be 3V above Vout.
Assuming the smoothing capacitors are big enough, a 15V
secondary would provide 15 x sqrt(2) - 0.7 - 15 = 5.5V.
Yet some people recommend a 2 x 18V transformer in this
application. Why ? It makes the regulators work harder. Is it
to avoid the bigger inrush current associated with larger
capacitors ?
Thanks in advance.
linear PSU. The LM317 and LM337 need Vin to be 3V above Vout.
Assuming the smoothing capacitors are big enough, a 15V
secondary would provide 15 x sqrt(2) - 0.7 - 15 = 5.5V.
Yet some people recommend a 2 x 18V transformer in this
application. Why ? It makes the regulators work harder. Is it
to avoid the bigger inrush current associated with larger
capacitors ?
Thanks in advance.