Servo direction

[fmw]

Hello

Do anybody now how to change the direction on a servo.

Regards
Finn
Denmark

[dirkan]

Hello Finn,

a servo position is determined by the pulse width of the input signal. Direction of movement is determined by setting pulse width more wide or smaller.

regards Dirk

[fmw]

Hi Dirk

Thanks Dirk, but is it posibel to change someting in the servo to revers it?

Regards
Finn

[P.Wolf]

Hi fmw,

it`s only an idea, but try to change the outer connections of the feedback poti inside of your servo unit. I guess this will cause a reverse function !

The other way could be to negate the input signal - this would certainly reverse all functions of your servo output mechanical gear. But i am sure this will be the more complicated way.....

regards


Peter

[P.Wolf]

Hi fmw,

sorry, but i have to say that my last decision was completely wrong !
I tried to change the two outer poti connections at a big servo mechanism myself, and saw that there was a uncontrolled run into one end position as result.
It`s logic, because there is a fixed mechanical connection given by the gear, driving the feedback poti.
You would have to change both , the poti connections AND the motor polarity, but this would cause absolutely no change at all, the motor will turn exactly in same direction as before !

I guess the only methode to reverse such a servo system is to invert the pulse signal , coming into the servo-amplifier, or , if possible , to invert the polarity or voltage level of the input signal feeding the servo-pulser unit. This seems to be the easier way.


regards



Peter

[dirkan]

Hi,

if this is a wish for an fsbus enhancement, a software solution is very easy. The values 0-255 have to be subtracted from 255 and that's all.
I think you will see this in next version.

regards Dirk

[dirkan]

Hi Finn,

sometimes its better to think a bit longer and then answer a question. The solution is still inside fsbus.
Set Multiplier = -1, Offset = 255

Original value Calculated value
------------------------------------------
1 1*(-1)+255 254
10 10*(-1)+255 245
250 250*(-1)+255 5

This is your solution, isn't it ?

regards Dirk

[fmw]

Hi Dirk


Your just great, this solve my problem, and it is function.

Thanks very much.

In few days, i will upload some picture of my instrument, how easy it is to make, by using some simpel parts from Simkit.

Regards
Finn