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Topic: Current divide 9v battery (Read 2931 times) previous topic - next topic

sandworm

Yes sir, that's the plan. Thanks for your help. Do you happen to know if the 7805 is the one I want?

Zapro


Yes sir, that's the plan. Thanks for your help. Do you happen to know if the 7805 is the one I want?


Most certainly not, that is a TO92/TO220 device and it won't fit the board.

Please tell me what Arduino you have and what rev. and i can give advice on what to replace the Vreg with.

// Per.

sandworm


Zapro


It's an Arduino Mega.


There are several revs of the Mega, which one is it ? Does it have the FTDI chip or the Atmel one for USB comms. ?

// Per.

sandworm

Its the 2560, with an atmel chip. 

Zapro

OK, then order these: http://goo.gl/qF7N0

Then you have 9 more for other projects :-)

Try to look at your regulator, I can see a destinct crater by the rightmost pin, is is dead for sure!!

Fault finding 101: First inspect visually for anything burnt/deformed.

// Per.

sandworm

Thanks Zapro. This picture really highlighted the divot in the v.reg, I can barely see it in real life. :)
I'll get some of those ordered asap.

MarkT



I picked up a 9v 2200ma battery to replace the piles of standard 9vs I've been going through. When I plugged it in, my arduino started to smoke, but I was able to unplug it in time to prevent permanent damage.


Ummm, if smoke came out then there's permanent damage...




Not if its a resistor that smokes - they can often burn off their coating and still work.   An overhot PCB trace can burn
off the solder-resist and still work (if lucky).

I agree it sounds like the battery pack wasn't connected to the right pins the right way round...
[ I won't respond to messages, use the forum please ]

sandworm

Any tips on desoldering the damaged surface-mount v.reg? I only have a soldering iron.

Zapro

Take a scalpel and carefully cut off the three legs alongside the body of the Vreg, after this you can easily desolder the remnants.

// Per.


sandworm

Worked like a charm, thanks everyone!!

Zapro

GREAT work!

Well done  :smiley-mr-green:

// Per.

sandworm

Thanks! Couldn't have done it without you, I appreciate the help.

smeezekitty

Good demonstration of how damaged components do not always fail immediately.

Smoke = damage.
Avoid throwing electronics out as you or someone else might need them for parts or use.
Solid state rectifiers are the only REAL rectifiers.
Resistors for LEDS!

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