DC Serial Servo Sanwa SRM-102's datasheet...

[Lai Chia Hung]

can somebody please tell me where can I get the datasheet/technical
specification for the Sanwan SRM-102 servo's...??? I need this very
urgently..... thanks......

[John R. Strohm]

"Lai Chia Hung" <lai...@pd.jaring.my> wrote in message
news:b4h02v$ap3$1...@news6.jaring.my...

> can somebody please tell me where can I get the datasheet/technical
> specification for the Sanwan SRM-102 servo's...??? I need this very
> urgently..... thanks......

Is this a radio control servo?

If so, they generally run off of +5V and ground, and the control signal is a
1-2 msec positive pulse at anywhere from 20 to 50 Hz pulse repetition
frequency. 1 msec pulse width (nominal) is hard over one way, 2 msec is
hard over the other, 1.5 msec is midrange.

Bypass the servo supply leads with a cheap 250 uF electrolytic capacitor, if
you build your own control circuit. I played with a Royal Titan Standard
servo several years ago. It drew 250 mA in smooth motion, and upwards of
500 mA while buzzing. That 250 uF capacitor was empirically determined to
be "about right" to stop the buzzing. (What was happening was that the
servo was putting hash back into the supply leads, and screwing up my 555
control circuit. Adding the capacitor cured it.)

[Roger Hamlett]

"John R. Strohm" <str...@airmail.net> wrote in message
news:C2C2D324A8B79FE1.9D3314B1...@lp.airnews.net...

The number, corresponds to a standard radio control servo. There is not
normally much 'data' for such servos, since the interface is 'standard' (as
described above). Normally the only specs, are for the size (mounting etc.),
and the speed/torque available. The Sanwa SRM 102, is listed as offering
3Kgcm torque, and 0.2 sec transit time for 60 degrees (at 4.8v), weighing
45g, and measuring 39*20*36mm. Sanwa, are sold in some countries under the
'Airtronics' brand name, and more data is available under this name (though
you then have to work out which is the equivalent Sanwa model - 94, followed
by the Sanwa number...).
A reasonably comprehensive list of servo specs, is at:
http://www.fatlion.com/sailplanes/servochart.html
The servo mentioned, is the Airtronics 94102.

Best Wishes

[Lai Chia Hung]

I can drive the servo with a PIC16F84A successfully, it works pretty
good..... the only thing is I need it's datasheet for my project
documentation, the company website doesn't provide such document, it is
possible I can found it some otherway...???

[John R. Strohm]

"Lai Chia Hung" <lai...@pd.jaring.my> wrote in message

news:b4hvmd$ijk$1...@news5.jaring.my...

Here's a web page that might help a little bit.
http://www.seattlerobotics.org/encoder/200009/Servos.html
NE544 was a Signetics part, long since discontinued. The circuit diagrams
in the page appear to be reproduced from an old Signetics databook.

Here's the datasheet for the M51550L.
http://www.mitsubishichips.com/data/datasheets/assps/assppdf/ds/M51660E.pdf
It doesn't say anything about the control signal waveforms.

Here's a discussion of digital proportional R/C systems.
http://www.rchelibase.com/radio/radio.pdf
This will probably cover what you need.

You might try writing a letter to Sanwa, telling them that you are a student
doing a project with one of their servos, and asking NICELY if they can send
you some literature. This may not be practical depending on how long it
takes mail to get to where you are. I don't know the .my domain; I'm
guessing Burma (Myanmar).