NetNews Usenet Archive 1993 #1/NN_1993_1.iso/spool/rec/models/rc/5341

Internet Message Format | 1993-01-06 | 1.7 KB

From: [e-mail] (David Cook)
Date: Wed, 6 Jan 1993 16:10:28 GMT
Subject: HELP - MOS/FET Speed Controller Problem
Message-ID: <[e-mail]>
Organization: HP Lake Stevens, WA
Path: sparky!uunet!think.com!sdd.hp.com!hp-cv!hp-pcd!hplsla!davidc
Newsgroups: rec.models.rc
Lines: 23

For several years I have controlled my R/C truck with an older Futaba 2 channel
2 stick radio and a Futaba MC12B MOS/FET speed controller. Recently I changed
the radio to a Airtronics VT2P 2 channel pistol-grip radio. Still wanting to
use the MC12B I changed the Futaba G connector to Airtronics, re-adjusted the
neutral and high point pots, connected the motor (a Kyosho 22x1 Outlaw Stock
MEGA Motor) and thought I was all set to go. WRONG!!! I got lots of
intermittant stutter both in the steering servo and the speed controller. This
was particularly apparent at slow speeds. Anyway I realized that since the
Airtronics receiver is a BEC type I should not feed the regulated +6 volts
from the controller back via the servo connector but should split it off and
feed it to the receiver's battery connector. I did this and got some improve-
ment but not what it should be. I can run the receiver with a seperate battery
and everything works great. Why is the +6 volts from the MC12B not good
enough for the Airtronics receiver? I checked it with my meter and it is +6
volts although I have not looked at it on a scope to see what kind of noise
may be riding on it. Do I need another capacitor across the motor terminals?
What is the proper configuration for motor capacitors?

Any comments, suggestions, ideas would be greatly appreciated.

Thanks in advance for your responses.

Dave