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12V 50A DC transformerless power supply for ignition of car!

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hatred88

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Plz help me!! i want to make a 220v AC to 12V 50A DC transformerless power supply on a PCB for mainly cranking a Car engine when the car battery's down in Power. Anybody have an idea, just share it here as soon as possible!!!!!
 

bepobalote

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Re: 12V 50A DC transformerless power supply for ignition of

I think 50A are far too low for starting a car engine:
the PEAK current can easily be more of 100-200A.
It would be better for you to use a portable Pb battery connected to the car battery, as almost every car electrician does.
 

hatred88

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Re: 12V 50A DC transformerless power supply for ignition of

Yes buddy you may b right b8 the current rating of a car battery is about 50A!! How can the battery provide far more current than its rating??? Although it is for a very short time b8 still how?????
 

bepobalote

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Re: 12V 50A DC transformerless power supply for ignition of

The peak current of a Pb battery is FAR more than the rated current: just take a look to any datashee_ for a typical Pb battery.
To simplify your life, you can check this one (for a 33Ah Pb battery):
VRLA_LC-R1233P
or this one:
VRLA_LC-P127R2P which is a 7.2Ah battery, but the curves show a 30A load lasting only 6 minutes...

But if you do not trust me, you can make a very simple test: put a 50A fuse in series to your battery and try to start your engine... Please let us know the results of the test.

P.S. what is the meaning of "b8" word? According to urban dictionary there are 4 different meanings: which one of them?

Added after 44 minutes:

A simple search on google showed me that an electrical crank motor for a diesel car motor (during a cold day) can have an inrush current of about 400A.
Gasoline (petrol?) car motors can require a peak current from 150 to 300A.
 

pranam77

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Re: 12V 50A DC transformerless power supply for ignition of

hatred88 said:
Yes buddy you may b right b8 the current rating of a car battery is about 50A!! How can the battery provide far more current than its rating??? Although it is for a very short time b8 still how?????
Yes it is a fact that bieng the rating is 50 Ah, the battery is capable to deliver about 5-6 times its capacity but for very short duration. The cranking of a car will naturally take 200-300 Amps from the battery.
 

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