I have finished testing the Neg_CH_MOSFET for use as a Polarity protecion device. The works Great with only a .28 voltage drop @ 8.91 input volts. Soon as I get my Tx I will be adding this .95 cent mod.
@ Darren We are talking about 2 different subjects here. Mine went POP & Smoked. When i opened up the transmitter peaces of the voltage regulator located on the switch board fell out on the table. It also pop the 5v regulators on the main board. What S.I. and I are talking about is if you put a diode in line to protect the curcuit it is also posible to pop it as well if power is left on to long connected the wrong way. I included a pic of my POPed regulator.
@ I.S. Small diodes, I did a diode test, When connected to the battery reversed it gets hot quick. So if you turn power on and notice the problem and turn it right back off you will probably be ok and wont burn out the diode.
I just got back from radio shack with a Neg-CH-MOSFET, They don't carry Pos_CH_MOSFETs in stock @ my store. I'm gonna do some testing with it and report back with info in a bit.
I did the same thing, (reversed the +/-) but got help from this post on rcgroups, it was really an easy fix... didnt think it would be, but one thing about soldering smc is, put a drop of solder on a piece of paper... then move the cap to it using a toothpick, then take away the soldering iron. the solder will not stick to the paper, but will the cap. then place the component in its postion and touch the pad (not the solder) briefly, it will melt the solder almost instantly. then remove the iron keeping pressure on the cap with your handy dandy toothpick (fingers dont like the temps :) )
once in place, the other side is just a dab of the wand, with still pressure from toothpick. (trick is not to keep the wand on thier too long, as it can easily remelt the other side.
one last thing; I found a trace burnt, and had to put in a jumper wire around it. but again, not huge issue.
copy paste from rc-groups.
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Me
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Speaking of lipo batteries... I just happen to reverse the bat connector and bam, blew up the processor board I already (back)ordered a new one, but does anyone know if there is a source for replacement board for a HK turnigy 9x? or do i now have spare parts
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Erazz
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When you do that you usually blow the 7805 and a capacitor. The replacement is really simple.
Use a voltmeter to check the voltage across your 7805. If it's zero then it's blown. Just replace it with a normal one.
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Me
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Yep found the blown cap and replaced, although it looks like 7805 is fine, but wasnt getting power input, followed the trace back and found a lift/burn of the trace coming from the battery on the front board. wired around the trace cut and walla, woohoo!!!
Comments
Now all I need is to find the manual and work out how to plumb everything into the airframe.
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=...
@russel, seems yours was a tad hotter of a pop than mine... :(
please share some pics of the mod when you get your new radio.
I have finished testing the Neg_CH_MOSFET for use as a Polarity protecion device. The works Great with only a .28 voltage drop @ 8.91 input volts. Soon as I get my Tx I will be adding this .95 cent mod.
@ Darren We are talking about 2 different subjects here. Mine went POP & Smoked. When i opened up the transmitter peaces of the voltage regulator located on the switch board fell out on the table. It also pop the 5v regulators on the main board. What S.I. and I are talking about is if you put a diode in line to protect the curcuit it is also posible to pop it as well if power is left on to long connected the wrong way. I included a pic of my POPed regulator.
@ I.S. Small diodes, I did a diode test, When connected to the battery reversed it gets hot quick. So if you turn power on and notice the problem and turn it right back off you will probably be ok and wont burn out the diode.
I just got back from radio shack with a Neg-CH-MOSFET, They don't carry Pos_CH_MOSFETs in stock @ my store. I'm gonna do some testing with it and report back with info in a bit.
Wow! blowing a diode reversing the batt??!
Unless you use abatt of hundreds of volts it shouldn't happen at all.
I did the same thing, (reversed the +/-) but got help from this post on rcgroups, it was really an easy fix... didnt think it would be, but one thing about soldering smc is, put a drop of solder on a piece of paper... then move the cap to it using a toothpick, then take away the soldering iron. the solder will not stick to the paper, but will the cap. then place the component in its postion and touch the pad (not the solder) briefly, it will melt the solder almost instantly. then remove the iron keeping pressure on the cap with your handy dandy toothpick (fingers dont like the temps :) )
once in place, the other side is just a dab of the wand, with still pressure from toothpick. (trick is not to keep the wand on thier too long, as it can easily remelt the other side.
one last thing; I found a trace burnt, and had to put in a jumper wire around it. but again, not huge issue.
copy paste from rc-groups.
----------
Me
---------
Speaking of lipo batteries... I just happen to reverse the bat connector and bam, blew up the processor board
I already (back)ordered a new one, but does anyone know if there is a source for replacement board for a HK turnigy 9x?
or do i now have spare parts
---------
Erazz
---------
Use a voltmeter to check the voltage across your 7805. If it's zero then it's blown. Just replace it with a normal one.
Thanks Erazz!!!!!
D
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