Darwen Cook posted a discussion
Type 300 course computer has low +/- 7.4 volts drive
I have a type 300 12volt course computer, Type 2 long M81132 linear drive unit with St7002 control head, fluxgate compus and rudder reference. Usually the course computer's output drive voltage to the drive unit is +/-12 volt or so and everything is ok. But occasionally the voltage only goes to +/-7.4 volts for about 10 seconds and then drops to 0 and there after the display shows "Drive Stopped". It is not the rudder reference, I can see the drive has stopped. I suspected a bad connection but the voltage into the 300s terminals is a solid 12 volts and the low voltage is measured at the 300's drive terminals. Of course I suspect the 300 but the exact voltage of both +7.4 and -7.4 makes me concerned that the driver might be detecting over-current and folding back to that voltage and that the problem is in the drive unit. What do you think? and what replacement is possible??See More