which fan should i buy 12V, 0.15 amp or 12V,3amp?

Ok i am building a project of controlling a fan's speed using pwm. Which fan should i buy 12v, 0.15 amp or 12v, 3amp. My requirement is the fan should have good speed.

What ever fan suits your needs, which as you haven't said other than mention the speed we do not know.

My requirement is the fan should have good speed.

Good is not a number you need to nail it down.

By good i mean decent speed such that the variation in different pwm output can be easily seen and felt.

can a 0.15 amp fan survive a 3 amp input? the voltage rating of fan is 12v

Ask yourself if your 500mA laptop power supply survives being plugged into a 10 amp + wall outlet.

In engineering terms that is not a good enough description to base a specification on.

Try asking your fan supplier.

can a 0.15 amp fan survive a 3 amp input? the voltage rating of fan is 12v

If it is a 12V 0.15A fan then there is no way you can get 3A through it without upping the voltage to 240V

Last query which fan to buy 12v 0.15amp or 12v 3amp. I really have no idea about limitations in my project so please enlighten me.

It probably depends on how much air you have to move, how fast and how much noise you can cope with

noise i can cope with so which one?

OK, so we've eliminated noise, that just leaves the other two.

You are the one with the datasheets. What do they tell you about the different fans?

@AWOL - the faster the better and the more air it moves the better.

@dannable - no datasheets here where i live 95% of the models you see in the internet are not available. Whats available is local made fans without any datasheet with ratings as 12v,1.5 amp and 12v 3amp. so what to do.

zammikao: the faster the better and the more air it moves the better.

In that case the more powerful the fan the better.

The amount of air moved is dependent on the speed of rotation and pitch of the blades, but that information is not to hand. Can you have a demonstration of the two types and make a decision then?

My only observation would be that 12V 0.15A sounds a little on the feeble side, model railway motors can draw more than that.