Servoproblem autothrottle

[imported_homecockpitbuilder]

I've made the throttle off my 744 driven by servo's and the phidgets servobord.

The problem is like Rob Howard said that the servobord cannot drive the servo's all 4 at once because the pcb burrns out.

I've connected all the wire's like the tutorial by Rob, but when i connect the power the servo only goes to the negative but not to positive direction.
When i use the servotester software i cannot drive the servo's.
The white wire in the tuttorial is yelow at my servo.

Can anybody help my white this problem?

Kind regards Bas de Louw

[mauriceb]

I've connected all the wire's like the tutorial by Rob, but when i connect the power the servo only goes to the negative but not to positive direction.
When i use the servotester software i cannot drive the servo's.
The white wire in the tuttorial is yelow at my servo.

Can anybody help my white this problem?

Kind regards Bas de Louw

I have used 2 servos in a 737 throttle assembly and that is working perfectly for me. I originally had some problems with the servotester program but it was just some kind of installation problem which I did not understand. I think it was missing some dll or something since it worked OK after I loaded Visual Basic on my PC and steppped through the program.

If the servo tester program does load properly for you but does not move the servos the way it should, then I would think that you did not wire things properly. The white wire is indeed yellow instead, so don't worry about that part. The main thing is to make sure the red positive wire is not going from the interface board to the servo. It has to be cut and the positive voltage should come from an external power supply to the red lead on the servos only. The black wires should all be tied together and go to the negative terminal of the power supply as well as to the interface board & the servo. The yellow lead should be left alone.

If you give me an e-mail address, I can take a picture of the cabling & send it to you tonight (it's morning here) in case what I said is not clear enough.

Regards,
Maurice