5V Power supply(AC to DC converter )

Thread Starter

Baskaran Manoharan

Joined Apr 18, 2016
5
This describes a similar supply.
I need the clarification of output side of the transformer

Transformer output one end (PWM signal) connected to CLC filter afer CLC filter we will get pure Dc output?

what purpose of Transformer other end connected Schottky diode cathode and snubber circuit?
 

AlbertHall

Joined Jun 4, 2014
8,181
I need the clarification of output side of the transformer

Transformer output one end (PWM signal) connected to CLC filter afer CLC filter we will get pure Dc output?

what purpose of Transformer other end connected Schottky diode cathode and snubber circuit?
On the secondary side there is also a rectifier diode. The output will not be pure DC, it cannot be, it will always have some ripple and some switching spikes. The filter on the output reduces this to some level acceptable for the circuit it was intended to power.
On the primary side, when the MOSFET switches off the drain voltage will rise above the supply voltage due to the inductive back emf from the transformer. The snubber circuit is there to protect the MOSFET from excessive voltage while wasting as little power as possible.
 

Dodgydave

Joined Jun 22, 2012
8,288
It's a Switchmode psu with opto-coupler feedback for voltage monitoring, and output isolation. the voltage is regulated using a Tl431 zener and opto-coupler, standard equipment on most switchmode psus.
 

Thread Starter

Baskaran Manoharan

Joined Apr 18, 2016
5
On the secondary side there is also a rectifier diode. The output will not be pure DC, it cannot be, it will always have some ripple and some switching spikes. The filter on the output reduces this to some level acceptable for the circuit it was intended to power.
On the primary side, when the MOSFET switches off the drain voltage will rise above the supply voltage due to the inductive back emf from the transformer. The snubber circuit is there to protect the MOSFET from excessive voltage while wasting as little power as possible.
secondary side Rectifying diode required?
 
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