# thyristor

Discussion in 'Homework Help' started by amjad..ali, Apr 12, 2015.

Apr 12, 2015
12
0
in this image if i removed the diode and Placed a thyristor
how can i find the value of R , Vr , Ir and the better type of thyristor for this circuits if i know the input is AC 220 volt and 50 Hz and power on the R is 10 K watt

2. ### R!f@@ AAC Fanatic!

Apr 2, 2009
9,618
1,088
Your Question is rather confusing !!

Apr 12, 2015
12
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why ??
i can explain it for you

4. ### R!f@@ AAC Fanatic!

Apr 2, 2009
9,618
1,088
Ask clearly. Provide all the info you have.
Partial questions might be ignored.

Apr 12, 2015
12
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ok
in the circuits diode be replaced by thyristor ok
all information is:
input voltage 220 and 60 Hz
power on the load 10 k watt

i need to calculation the value of Resistance , the current into the Resistance and voltage on Resistance
how can i found it

6. ### Ramussons Active Member

May 3, 2013
623
104
The ONLY resistance I see is the Load.

Unless you give a schematic, we cannot give any meaningful answers.

Please tell us what you are intending to do. Why do you want to replace the Diode by a Thyristor? In the present setup, the Load has a Pulsating DC. A thyristor in place of the Diode will give a clipped AC.

Apr 12, 2015
12
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yes the resistance is the load i mean it
i want to do a homework about single phase full wave controlled rectifier center tap with 10 k watt
i replace the diode because i need controlled rectifier

8. ### Dodgydave AAC Fanatic!

Jun 22, 2012
6,476
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what voltage is the secondary winding , what is the current?

Apr 12, 2015
12
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the voltage in the primary is 220 volt so in the secondary will be 110 on the up half and 110 on the down half
the current i don't know its value

10. ### R!f@@ AAC Fanatic!

Apr 2, 2009
9,618
1,088
That secondary is 110VAC-0V-110VAC.
The Power of the R is 10KW.

Assuming the former is delivering and R dissipating 10KW.
From the diagram you provided, ⇒
Vdc = 0.45 X 220VAC ⇒ 99VDC.
So, Now you know DC voltage.
Use ohms law and Power = VI equations to find R and I.

Apr 12, 2015
12
0
ok thank you
but Vdc = 0.45 * 220
can you tell me the 0.45 from where

and the Vdc its the same v

12. ### R!f@@ AAC Fanatic!

Apr 2, 2009
9,618
1,088
Vdc is the Voltage seen by the R.
0.45 x 220VAC ⇒⇒ 0.45 is really the formula used for center tap Bridge rectifier without a smoothing capacitor and 220VAC is the AC voltage available at the Tx secondary across the entire coil.