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Dec 11, 2001, 07:01 AM
Registered User
Bleriot's Avatar

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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Dec 11, 2001, 10:03 AM
Senior Moment
rlt55's Avatar
Here is a 1 amp unit http://www.epanorama.net/circuits/lm317.html
I use them all the time. Work just fine.
Dec 11, 2001, 08:33 PM
Crash Master
Gene Bond's Avatar
Here's another:

Li-Ion Charger

Notes & Hints:

Keep a fire extenguisher handy!!!
Don't drill cooling hole in batteries.
Dec 11, 2001, 10:46 PM
ClearView Rocks!
Quacker's Avatar
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.
Dec 13, 2001, 12:22 AM
Almost a Pilot
Mauilvr's Avatar
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.