Paddle log, Navico

[Artimes]

This unit although mounted in the correct hull location gives intermittant readings, aparently in a random manner not related to boat heel or speed. Is it possible to monitor directly the output from the paddle? ie, voltage pulse or any other electrical quantity. It it possible to input to the indiacating instrument a test pulse signal and what would be the kind of signal neccessary?
thanks.

 

[steffen]

The Navico paddlewheel i have has magnets in the paddles and a reed relay in the fixture. Every time a paddle passes the reed it closes resulting in a infinite or zero resistance.
if you connect a small battery and an oscilloscope in series with the paddle unit you should see the pulses or the absence of it.

 

[Charieis]

My one only had two magnets in opposite paddles, so don't be surprised if you only get half the pulses. I replaced the reed switch on one once, years ago, having chopped the end off the unit. I think I got one from RS Components and repotted it in resin as per the original, if I remember correctly.