Fly
Back DC to DC converter, is a derivation
of Bust Converter, but instead of store the energy and delivery it
directly to a capacitor, it had internal windings and the energy is
stored in the gap of the transformer. Then deliberated on their
secondary winding, diodes also works exactly like the bust
converter, it will delivery the energy on the capacitors Just when
MOSFET is OFF like the Bust converter.
Fig
1 show the basic principle, Fig 2 MOSFET is modulated by the square
wave, Fig 3 represent the total control of the fly back, R3 sense
the voltage output and it is compared with voltage reference Vref. photo
isolated transistor then feedback the PWM signal required to
regulate the voltage according to the value of Diode Zener Vref.
Advantages/Applications:
Its
is usedfor:
Low
cost , Multiple outputs
Output
current less than 7 Amps
Good
voltage tracking between outputs
Fast
transient response
Only
one diode per output
No
filter inductor in secondary
Feed
forward compensation in current mode schemes.
This document and intellectual
content is propriety of
APSDC.com, All rights reserved, and can not be reproduced or copied under
written consent of APSDC.com, unless denoted here.
