encoder to rpm calculation

S

Thread Starter

southencross

hi guys,

I'm still very new to optical encoder, can you guys please tell me how to convert the paulse to RPM, velocity and acclerations?

the device i use is as follows:
DC geared motor with 65:5:1 ratio
motor no load speed 59 rpm
optical encoder counts 500ppr

lastly can you guys also tell me what is those base 2 singnals for?

thanks
 
Where is the encoder, on the back of the motor or tied to the output shaft of the gearbox? It makes a difference in the calculation...
-Aaron-
 
S

southencross

the encoder is couple directly to the rotor of the motor. NOT on the the output shaft of the gear box
 
RE: RPM
For proper output shaft rpm you need to base your calculation on a fixed time base, I have done this before on a small plc using a fixed time interrupt program. Here is an example using a fixed One seccond Interrupt.
Output RPM = ((Pulses Recieved in 1 sec * 60) / PPR) / Gear Ratio

As for Accel and Decel you can store the result of your calculation and every time you update, check weather the new RPM is greater / less then the last value.

 
D
By this I assume you mean the A & B signals which are the output of an incremental encoder, these signals are normaly 90' out of phase with each other so as to provide direction information i.e. A before B or B before A.
 
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