A problem in Coupling Transformers

[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 !

 

[gneill]

My solve is :
V(out)=nV(in)
V(out)= 2 * 312 = 624 v
PIV = V(out) = 624 v

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.

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 ..

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?

 

[bibo_dvd]

What does that tell you about the resulting potential across the load resistor?

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 ??

 

[gneill]

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 ??

Looks good!

 

[rezeew]

I would like to first commend you for your efforts in studying and trying to solve the problem with coupling transformers. Based on the information provided, it seems like you have correctly calculated the output voltage using the formula V(out) = nV(in). However, I would suggest double-checking your calculations to ensure accuracy.

Regarding the issue with the diode, it is correct that if the diode is reversed biased, no current will pass through RL and the output voltage will be zero. However, it would be beneficial to also consider the effects of the transformer's leakage inductance and the load impedance on the output voltage.

In order to fully understand and solve the problem, it may be helpful to review the principles of transformer operation and the behavior of diodes in circuits. Additionally, consulting with a more experienced scientist or seeking additional resources may also aid in your understanding and solving of the problem. Keep up the good work!