# A problem in Coupling Transformers

1. Oct 29, 2013

### bibo_dvd

Hello Guys !!

While Studing coupling transformers i found this problem
i tried to solve it
but i don't know if my solving is right or no !!
so tell me :)

The problem :

My solve is :
V(out)=nV(in)
V(out)= 2 * 312 = 624 v
PIV = V(out) = 624 v
and if the diode is turned around it will be reversed biased so no current will pass across RL and
Output voltage will equal to zero ..

am i right guys or what ??

Thank you !!

2. Oct 29, 2013

### Staff: Mentor

Looks okay. Although whoever set the problem doesn't know his components very well. A 1N4002 diode as a PIV rating of about 100 V if I recall correctly. Expect the magic smoke to escape from the diode very shortly after switching on!

Also, you have ignored the ~0.7 V forward drop across the diode. Probably okay considering what a small percentage this is of the total voltage.

Nope. The secondary will present a full AC voltage signal, so if you turn the diode around it will simply conduct when the diode is forward biased on the opposite half-cycles (opposite that is to the half-cycles when it conducted in the original diode orientation). What does that tell you about the resulting potential across the load resistor?

3. Oct 29, 2013

### bibo_dvd

I think the potential across the load resistor will be the same but with an opposite sign
i mean that the voltage will take this shape ..am i right ??

4. Oct 29, 2013

Looks good!