I picked up a 22uH power inductor, as listed in the parts list.. and it looks more like a resistor than what the one in the pic looks like. What exactly is that part? I asked the guy in the shop and he pretty much didn't understand why it was being used in the first place... so no help there. I also got a 22mH which looked similar to the one in the pic, but I'm not going to use either one until I know if it'll work.
Someone please help.. I'd like to finish this up..
'22uH Power Inductor' doesn't look the the same...
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It's the same size as a normal resistor.
I was just going to solder it where it's supposed to go. There isn't a polarity marking, so I guess it just goes in there... but I'm really confused as to why the one in the pic looks so much different than what I got. Just want to be sure what I have will still work.. don't want to fry anything.
I was just going to solder it where it's supposed to go. There isn't a polarity marking, so I guess it just goes in there... but I'm really confused as to why the one in the pic looks so much different than what I got. Just want to be sure what I have will still work.. don't want to fry anything.
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The one that comes with the kit now and is pictured in the instructions has an ferrite core and both wires on the same side of the part. The first prototype made by LA used a different inductor that was mounted on top and across the IC and it did resemble a large black resistor - it also had a ferrite core.
There are also inductors with a air core (nothing in the middle of the coil). Variable inductors use a movable ferrite core that moves up and down inside the core varying the inductance of the part.
Some times, in some DIY projects, you also find instructions to create your inductor by wrapping very fine enamel copper wire around a resistor, soldering each end of the wire to each side of the resistor - making it a carbon core inductor.
The easiest for you would be to try the circuit on a prototype board first and compare the behavior of the mintyboost with the two different inductors you have.
Posting a picture of the part (placing the picture somewhere in the internet and adding the link to a reply) would also allow others to maybe recognize it.
There are also inductors with a air core (nothing in the middle of the coil). Variable inductors use a movable ferrite core that moves up and down inside the core varying the inductance of the part.
Some times, in some DIY projects, you also find instructions to create your inductor by wrapping very fine enamel copper wire around a resistor, soldering each end of the wire to each side of the resistor - making it a carbon core inductor.
The easiest for you would be to try the circuit on a prototype board first and compare the behavior of the mintyboost with the two different inductors you have.
Posting a picture of the part (placing the picture somewhere in the internet and adding the link to a reply) would also allow others to maybe recognize it.
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Here you can see a color table (same coding as resistors) for inductors:
http://www.elexp.com/t_induct.htm
Current rating as Hal pointed out maybe the issue here. By the size of it (it seems to be size of 1/4W resistor from the picture), it is probably not rated for 1.2A as required to be used by the MAX756 IC.
On this page of the Digikey US catalog you can see similar inductors to yours and their dimensions. The rating is indeed much lower at 190mA.
http://dkc3.digikey.com/PDF/T062/1042.pdf
On the paper Digikey catalog (Hong Kong version 051), I found some more inductors similar in size to yours and they are all rated at 144 mA to 295 mA.
All axial inductors rated for more than 1.0A seem to be at least 10 mm in diameter.
http://www.elexp.com/t_induct.htm
Current rating as Hal pointed out maybe the issue here. By the size of it (it seems to be size of 1/4W resistor from the picture), it is probably not rated for 1.2A as required to be used by the MAX756 IC.
On this page of the Digikey US catalog you can see similar inductors to yours and their dimensions. The rating is indeed much lower at 190mA.
http://dkc3.digikey.com/PDF/T062/1042.pdf
On the paper Digikey catalog (Hong Kong version 051), I found some more inductors similar in size to yours and they are all rated at 144 mA to 295 mA.
All axial inductors rated for more than 1.0A seem to be at least 10 mm in diameter.
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Thanks & a question
Firstly thanks for the excellent MintyBoost, i built mine point-point and it works great.
My question is the 22uh inductor i ordered looks like the one above,( i need an axial vers 'cos i built the single layer prototype) what will the downside be: overheating if charging my iPod for a long period/more serious? fire risk?
thanks
My question is the 22uh inductor i ordered looks like the one above,( i need an axial vers 'cos i built the single layer prototype) what will the downside be: overheating if charging my iPod for a long period/more serious? fire risk?
thanks
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Please be positive and constructive with your questions and comments.