REFLECTOR: IVO motor, hitting the stops

[Sid Knox]

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----- Original Message ----- 
From: "Laurence Coen" <lwcoen at hotmail.com>
Subject: Re: REFLECTOR: IVO motor


John,

I had the same thing happen to me.  In my case the motor was taking 
excessive current.  When the prop passes thru the neutral position, the 
motor should take about 2 amps.  Mine was taking 20 amps and would stall 
before getting to the stops.  You can check this by running the prop pitch 
with the engine stopped and watching the ammeter.  It took three trips back 
to the factory to get it fixed and I'm still keeping my fingers crossed.  I 
also talked with Ivo himself several times.  He is currently living in the 
middle of nowhere Utah.

I never liked the idea of the mechanical stops that simply stall the motor 
and the only way you know you have reached the limit is when the breaker 
pops.  The current rises very rapidly when you get to the stop. I designed a 
current limiter circuit that shuts off the motor before it stalls and turns 
on a light to let you know that you are at the limit.  It seems to be 
working well.

Larry Coen
N136LC
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The German MT electric prop uses a similar scheme.  No mechanical stops. 
The controller senses the current rise at the end of travel.  Works well.

Sid