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Electronics => Electronics => Topic started by: manut on December 30, 2009, 07:12:03 PM

Title: modified servo-->different direction, different speed...??
Post by: manut on December 30, 2009, 07:12:03 PM: hi,
I modified a new servo, I already succeeded with two other ones..
this one works, but doesn't have the same speed if it's forward or backward...
I used the 2.2k resistors for the modif...
does somebody know where it could come from..?
thanx
manu
Title: Re: modified servo-->different direction, different speed...??
Post by: SmAsH on December 30, 2009, 07:16:06 PM: Were the 2k2 resistors 1% tolerance?
Title: Re: modified servo-->different direction, different speed...??
Post by: manut on December 30, 2009, 07:41:51 PM: it's actually a gold stripe..so 5%..right? ...I controlled the resistance with my multimeter before to solder them..it was 2.17k, both of them.. Do you think it could be the cause of my prob? I thought that a so small difference wasn't important, but...
Title: Re: modified servo-->different direction, different speed...??
Post by: SmAsH on December 30, 2009, 07:43:55 PM: I'm not sure if its the cause of your problem but they're supposed to be precision 1% resistors?
Title: Re: modified servo-->different direction, different speed...??
Post by: manut on December 30, 2009, 07:51:12 PM: okay, I'll try with 1% tolerance, because I did it two times exactly the same way but the resistors were exactly 2.2k (measured with the multimeter)..
thanx
Title: Re: modified servo-->different direction, different speed...??
Post by: Soeren on December 31, 2009, 07:00:11 PM: Hi,

Quote from: SmAsH on December 30, 2009, 07:43:55 PM
I'm not sure if its the cause of your problem but they're supposed to be precision 1% resistors?
Most 5% resistors are way closer than 5%
Besides, it doesn't matter, if the servo is steady at 1.5ms, it's close enough and they don't have to be 22k! eg. 10k, 47k or 100k will be just fine, as long as they're the same value. They are just there to establish a midpoint for a stopped servo at 1.5ms, nothing else!