quadrature encoder vibration problems

[2000]

hello friends,

I've already posted a message about quad. encoders, but as the project goes more problems arises. Actually I've a hardware that is able to count the pulses and tell the direction, but when I connected the encoder in the shaft of the AC motor sometimes it miscounts or bad counts the pulses I guess it's due to vibration in the startup or stop.
The software obies the state machine to pass by the 4 states before it increments or decrements the position. Each time there's a transition (up or down) in the A or B channel an interruption is generated and the state is stored.
What more could be done to get rid of this bad counts?

thx for any help,

regards,

2000

 

[samsuffy]

diff line driver

I haven'ts seen your previous msg...

maybe :
Do you take care to the link between the encoder and the counter ?...

Some parasitic voltages can easily disturb the counter !

A way to avoid it :
use differential line driver : as rs485, see national semiconductor web site

Good luck

 

[bunalmis]

You can use digital filter for A and B signals.

You can build electronics or writing simple software.