electronic question

• mr_sotong

  30 Nov 07, 23:47

  how to get the capacitance if given:
  
  Vpri = 220v 50Khz
  Vsec = 44v
  0.5%ripple
  RL-1kohms
  Isurge(max) = 1A
  DC output voltage = 15v
• turbo_drift

  1 Dec 07, 12:35

  Formula:
  
  C = Q/V
  C = Q/15v
  
  p.s: But i dunno how to get Q (total charge) leh..
• eagle

  1 Dec 07, 12:36

  Originally posted by mr_sotong:

  how to get the capacitance if given:
  
  Vpri = 220v 50Khz
  Vsec = 44v
  0.5%ripple
  RL-1kohms
  Isurge(max) = 1A
  DC output voltage = 15v

  no circuit diagram ?
• mr_sotong

  2 Dec 07, 11:49

  Originally posted by eagle:

  no circuit diagram ?

  no.. only numbers was given..
• eagle

  2 Dec 07, 15:17

  Originally posted by mr_sotong:

  no.. only numbers was given..

  because the labels are so short
  
  Vpri
  Vsec
  RL
  
  etc...
  
  We won't know what it stands for, nor what topic is it from.
• turbo_drift

  3 Dec 07, 12:46

  Originally posted by eagle:

  because the labels are so short
  
  Vpri
  Vsec
  RL
  
  etc...
  
  We won't know what it stands for, nor what topic is it from.

  Vpri = voltage primary
  Vsec = Voltage secondary
  RL = Resistor i think..
• mr_sotong

  3 Dec 07, 22:10

  Originally posted by turbo_drift:

  Vpri = voltage primary
  Vsec = Voltage secondary
  RL = Resistor i think..

  Load Resistor to be exact..
• turbo_drift

  3 Dec 07, 22:10

  Originally posted by mr_sotong:

  Load Resistor to be exact..

  paiseh lah.. got learn electronics but nvr learn RL..
• Darkness_hacker99

  4 Dec 07, 00:18

  Excused me..
  
  This question still need an answer mah?
• turbo_drift

  4 Dec 07, 00:18

  Originally posted by Darkness_hacker99:

  Excused me..
  
  This question still need an answer mah?

  of course.
• Darkness_hacker99

  4 Dec 07, 18:36

  For the past few nights, I have been searching the net hopping something would shed light on this question..
  
  Hmm~ Still can't find it leh.
  
  This question is it related to transformers anot?
  
  
• mr_sotong

  4 Dec 07, 20:04

  Originally posted by Darkness_hacker99:

  For the past few nights, I have been searching the net hopping something would shed light on this question..
  
  Hmm~ Still can't find it leh.
  
  This question is it related to transformers anot?
  
  

  ya.. its a step down transformer..
• eagle

  4 Dec 07, 20:37

  not enough information was given
  
  and now we are told it is a step down transformer after 11 posts
  
  Any more information missing?
  
  Let me guess
  
  Vpri is AC
  Vsec is AC
  Output voltage is DC (15V)
  Rectifier circuit was used in conversion from AC to DC, and hence the ripple
• eagle

  4 Dec 07, 20:42

  In addition, the circuit on the secondary side can thus be seen as shown:
  
  
  
  The capacitance in the diagram is what you need to find right?
• mr_sotong

  4 Dec 07, 20:56

  Originally posted by eagle:

  In addition, the circuit on the secondary side can thus be seen as shown:
  
  
  
  The capacitance in the diagram is what you need to find right?

  yup..
• eagle

  4 Dec 07, 21:04

  Originally posted by mr_sotong:

  yup..

  Originally posted by eagle:

  no circuit diagram ?

  Originally posted by mr_sotong:

  no.. only numbers was given..

  
  
  I look at it later... Damn long ago since I seen this type of question...
• Darkness_hacker99

  4 Dec 07, 23:40

  Originally posted by mr_sotong:

  ya.. its a step down transformer..

  Aiyo! Why never say earlier!!
• mr_sotong

  5 Dec 07, 11:59

  Originally posted by Darkness_hacker99:

  Aiyo! Why never say earlier!!

  but but but its already very obvious since i already stated that Vpri is 220v and Vsec is 44v..
• Darkness_hacker99

  5 Dec 07, 14:25

  Originally posted by mr_sotong:

  but but but its already very obvious since i already stated that Vpri is 220v and Vsec is 44v..

  
  
  I read that the main current is determined by the turn ratio.
  
  which is Vpri/Vsec = 220/44 = 5.
• eagle

  6 Dec 07, 10:47

  Originally posted by mr_sotong:

  but but but its already very obvious since i already stated that Vpri is 220v and Vsec is 44v..

  that part is obvious
  
  the circuit is not
  
  btw, the circuit posted above is still missing something. I still fail to see why Vsec is 44V while Voutput is 15V
• mr_sotong

  7 Dec 07, 08:18

  Q = Integral of Current with respect to time
• eagle

  7 Dec 07, 08:40

  Is this a part question or a full question?
  
  Do you have the circuit diagram in your notes?
  
  What is the topic about? Transformers?
  
  Seriously, just be giving only a mess of numbers and no other explanations as to what the numbers mean, we as outsiders of your school subject/module wouldn't be able to fully understand the question. It is tantamount to me giving you
  V=20V, R1=5ohms, R2=5ohms, R3=10ohms, Find I
  You wouldn't know if the circuit shows the resistors as parallel or in series.
  
  So please, list down all available information and do not just blindly copy the question, including any circuit diagrams, etc. It is also a good training for you to do so as the best way to solve any question is to understand and gather internally all the required information to do so.