Servo failed

[Orac]

Hi all,

Any idea what the motor winding resistance should be on a Kondo 4024HV?

I am reading about 0.3 ohms when a FET is removed

The servo blew a FET and I replaced both fets, now the servo works sluggishly, but the current draw is massive.

It looks to me like the winding has failed causing the original fet to blow

I replaced the original HAT3004's with IRF7389's which should be compatible.

Any ideas?

[PaulP]

One of my 788 servos did that, ran sluggishly then eventually blew. I never read the resistance of the motor before it eventually blew though..

I have just done some quick tests on the duff 788 motor.

It reads 0.3 ohms open circuit but when I apply 5V across the motor, the voltage drops almost to 0v and the current goes up to over 1A but the motor doesnt turn anymore.

I dont have access to any working motors that arent in circuit at present so I cant really give you any more info.

[Orac]

Thanks, I suppose, I'll have some parts now in case another servo blows or breaks a tooth, I bought a tube of FET's from Farnell.

I'll do without the head movement for the moment, not really an issue to me.

[PaulP]

I think IXS is the same mother company for both bots. Contact Limor, he gave me a guys name at IXS and he might be able to help out. These things arent cheap and there does seem to be some teething problems with them..

You never know, they might do a Hitec and fix it for free....