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Old Dec 11, 2001, 08:01 AM
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Bleriot's Avatar
Joined May 2000
2,837 Posts
7.2-7.5V Voltage regulator

Hi Is there a circuit diagram using easily available parts to build a voltage regulator to put in between a 3 cell Tadrian Lithium Battery pack (10.2V off the charger) and the esc so that the esc never sees more than 7.5 volts? Thank you. Best Regards
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Old Dec 11, 2001, 11:03 AM
Senior Moment
rlt55's Avatar
Woburn, MA, USA
Joined Jul 2001
624 Posts
Here is a 1 amp unit http://www.epanorama.net/circuits/lm317.html
I use them all the time. Work just fine.
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Old Dec 11, 2001, 09:33 PM
Crash Master
Gene Bond's Avatar
Indianapolis, IN
Joined Sep 2001
16,632 Posts
Here's another:

Li-Ion Charger

Notes & Hints:

Keep a fire extenguisher handy!!!
Don't drill cooling hole in batteries.
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Old Dec 11, 2001, 11:46 PM
Quacker's Avatar
United States, CO, Longmont
Joined Jul 2001
2,829 Posts
Hi Bleriot. I just found this thread. The LM317 has an internal current limiter that may be too low for you. The TO-220 package is limited at 1.5 amps peak. After this point, the voltage will drop off in order not to excede 1.5 amps. The part also has a minimum voltage drop of about 2.25 volts at 1.5 amps. This means that as your battery voltage drops, it will have to be more than 7.5 + 2.25 = 9.75 volts to keep the voltage in regulation. If the battery gets lower than this, the output of the 317 drop down as well. There are regulators that have a lower (better) dropout voltage than this. You should also anticipate needing a heatsink.
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Old Dec 13, 2001, 01:22 AM
Almost a Pilot
Mauilvr's Avatar
NorCal
Joined Oct 2001
3,760 Posts
Bleriot:
You can't drill cooling holes in the regulators either.
Don't waste your time writing National Semicinductor asking them to drill cooling holes in their regulators - they won't listen either.
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