>Carlos,
>
>The value is not really unreasonable with a 60Hz supply.  It's hard to
>tell the magnitude of the ripple on the bridge output caps C1 and C2 since
>we don't know what the load current is.  We do know however, that it will
>be at 120Hz and that the designer thought that it would be large enough to
>bother with additional filtering.  We can calculate the inductive
>reactance of the inductors L1 and L2 (at 120Hz) and the capacitive
>reactance of the output caps C3 and C4 (again at 120Hz) and see that the
>designer was trying to reduce the 120Hz ripple.  With inductors and
>capacitors an order of magnitude smaller, say 0.1H and 10uF, there would
>be very little reduction in 120Hz ripple but at the values chosen, the
>reduction would be substantial.
>
>There are many combinations that the designer could have chosen and a
>variety of tradeoffs that he might have made.  These might include size,
>cost, availability, reliability and energy storage.
>
>Regards,
>
>Dave
>
>Carlos A. Marcano V. wrote:
>
>>Hi piclisters.
>>
>>I am currently troubleshooting failures on a pretty old power supply. I am
>>attaching the schematic (I hope it is not too big). It is a simple (an
>>inefficient) circuit but there is something that intrigates me, the value
>>of L1 an L2 which are 1H, (isn´t that too much?). If this is right, why is
>>this value used? Thanks for your help.
>>