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Voltage Reading/ Voltage Drop 
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#1
Aug911, 03:13 AM

P: 10

When we take down voltmeter readings from the terminals of a Rectifier (rated 12V), we get the voltmeter reading as 4.5V. Does that mean the rest of the voltage is lost in the form of voltage drop? or is it because of the current drawn by the load? I would be glad if someone could please post the answer.
Thanks. Numair 


#2
Aug911, 01:00 PM

P: 1,822

If you measure the voltage on the other side of the rectifier, with the voltmeter set to AC, what voltage do you read?



#3
Aug911, 01:02 PM

P: 10

its coming out as 4.5Volts...so i want to know if the rest of the voltage is lost in voltage drop? or is it because of the current that the load on the secondary that is withdrawing. thanks



#4
Aug911, 05:14 PM

P: 1,822

Voltage Reading/ Voltage Drop
Voltmeters put a very, very light load on the voltage being measured so no I don't think the voltmeter is loading the power supply. It's much more likely there's some other problem causing low voltage.



#5
Aug911, 08:23 PM

P: 3,904

If you don't have a filter cap, the output of the rectifiers is still AC( well, call it varying DC like you turn the negative half of the sine wave around and become like lumpy waveform), you are measuring the DC component of the rectified lumpy voltage. Put a 22 to 100 uF cap across the output and you should get the voltage.
If not, then read the AC voltages to make sure you have everything hooked up correctly. 


#6
Aug911, 10:56 PM

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#7
Aug911, 11:27 PM

Mentor
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#8
Aug911, 11:33 PM

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#9
Aug1011, 02:41 AM

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#10
Aug1011, 03:13 AM

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