7.2-7.5V Voltage regulator - RC Groups
Shop our Airplanes Products Drone Products Sales
Thread Tools
Dec 11, 2001, 08:01 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
Sign up now
to remove ads between posts
Dec 11, 2001, 11:03 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, 09:33 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, 11:46 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, 01:22 AM
Almost a Pilot
Mauilvr's Avatar
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.