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DC to DC converter. Measure output current

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roronoa

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DC to DC converter

Hi everyone,I have a source of 2.5V but i dono how much is the currect, i used a voltage doubler circuit and gain an output voltage of 5V ,but im still unable/ or no idea how to measure the current. When i connect a resistor across the the output voltage(and put the multimer in series) it gives me 0A.

Actually i wan to use this 5 V to create a input voltage for my cellphone charger but when i plug the output of the voltage of the voltage double into the phone the output voltage becomes 1.2V and it is no longer 5V.

Can anyone tell me why is this happening?Is it because the current is too low?and is there anyway of solving this problem?
 

som_raparty

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Hello
first thing i would say is it would have been lot helpful if u hvae posted the circuit,
any how as you are saying that when you connect it to mobile for charging, the out put is no longer 5V, but gts reduced, it is a clear indication that your converter is loading, it is not bale to source teh required current for your charging, i even guess that your converter will be heating up also!!!!
 

Antonyb

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Hi roronoa,
Its simple ohms law. When you monitor the Voltage, there is not much current flowing and hence 5V.
But when connected it gets loaded and not able to source the required current, and the voltage drops.
Its better you dont use this circuit any more for safety and post the exact circuit which you have used for further analysis.
 

som_raparty

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hi
its just simple that your circuit is loading,
if you want to know how much current it can source connect a variable resistor across the o/p and check the i/p voltage by varying the load, at some point the voltage drops measure the resistace by which you can calculate what is the maximum currnet it had gone with the 5V
 

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