RayMarine AutoHelm 1000 AutoPilot shaft movement query

[valeria]

Hi,
I have currently (almost) repaired and serviced a faulty AutoHelm 1000.

My Question....

I am left now with one problem. I think the unit is too much sensitive now. At a slight movement, the shaft travels almost full length. I am assuming that with a few degrees, the distance travelled by the shaft should be proportional. Can someone confirms this please?

Anybody knows if someone has a copy of the circuit diagram. It would really help me out.


Useful Info

My initial problem was the arm extends in 1 direction only and some other dodgy behaviour. To cut it simple, I had to dismantle the compass unit, to find the two red LEDs not working due to common resistor failure.

I have uploaded a small video clip as many have asked about the mystery inside the compass unit (not a flux gate). This clip gathers some relevant images found on the net and added my contribution to it.

http://www.youtube.com/watch?v=My1mgTBlX1U

I have now a good compass unit. Had also to replace IC LM324 as one of its 4 internal op-amp was duff and soldered all output transistors due to visible dry joints. Now everythings seems working :4v rest position, 3.7v and below starts retracting, above 4.3v starts extending.


Hope I have helped someone too

 

[nigelmercier]

At a slight movement, the shaft travels almost full length...

I know nothing about this unit, although I know a little more after seeing your video. However, the symptom you describe sounds like a feedback sensor not operating.

 

[misterg]

... At a slight movement, the shaft travels almost full length. I am assuming that with a few degrees, the distance travelled by the shaft should be proportional. Can someone confirms this please?

If it's anything like its newer siblings, then that sounds like normal behaviour. The motor keeps driving as long as there is a heading error - it's not proportional. There's probably a gain adjustment somewhere that controls the sensitivity.

I'm sure that there's a schematic for this on the web somewhere, but I haven't been able to find it in 5 minutes or so of looking.

I know nothing about this unit, although I know a little more after seeing your video. However, the symptom you describe sounds like a feedback sensor not operating.

I don't think it has one - certainly the newer ST1000 / 2000 / 4000 tiller pilots don't (it's optional on the 4000, I believe).