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Need help on Cap value for V "smoothing"

rotagen

Mar 27, 2011
1
Joined
Mar 27, 2011
Messages
1
Hey all,

I have installed a "hack module" into my Radio Control transmitter converting the Tx from FM to 2.4 GHz.

The problem was once installed, I got voltage flickering on my Transmitter which was designed for FM, so it saw the lower V as a battery runout problem and beeped constantly.

Forums on RCgroups gave me an answer, to solder a capacitor between the + and - leads of the hack module at the circuit board.

Problem is, I have heard 47uF and 470uF as the proper value for this capacitor.

Only thing I can give you is the Tx is running on 11-12 Volts when the battery is fully charged. My 47uF cap solved the flickering Voltage problem, but am I in danger of not supplying the full voltage to the module with this value of a cap?

Heres some more info that may help, the voltage readings on the transmitter (without the cap installed) are bouncing from 11.3 to 8.2.

I'm guessing if the value is too small, its the equivalent of a short circuit.
 
Last edited:

davenn

Moderator
Sep 5, 2009
14,264
Joined
Sep 5, 2009
Messages
14,264
no, the capacitor value wont change the voltage it will just help smooth out the variations in the voltage. if its a 10 - 12V supply use a capacitor of at least 16V rating preferably 25V. The voltage rating of the capacitor is to protect the capacitor, it wont affect the operation of the circuit.

cheers
Dave
 
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