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Electronics => Electronics => Topic started by: bubbletea7 on March 13, 2011, 09:35:14 PM

Title: help to link with oscilloscope..
Post by: bubbletea7 on March 13, 2011, 09:35:14 PM
hello there,

 I am doing a dc motor controller for positioning application..the encoder have been attach to the motor to sense the position of the motor. this project have 3 speed (which is mean have 3 different number of PWM).

So, my lecturer ask me to prove the three speed using an oscilloscope. so, how should i connect my hardware to the oscilloscope , to check the digital output from the encoder( it have 2 output). so 1 need to prove the speed with 2 quadrature waveform from the scope.

How should i link it? is it i need to link the oscilloscope with the PIC pin connection or from the encoder pin?

tq for helping me.
Title: Re: oscilloscope help.!
Post by: vinniewryan on March 13, 2011, 10:15:40 PM
If you connect your scope to the PWM output, you can monitor the pulse width output for each of the three speeds. This will prove that your PWM is actually changing frequency with each of the 3 speeds.
Title: Re: help to link with oscilloscope..
Post by: Joker94 on March 13, 2011, 10:57:37 PM
To connect your device you need to connect the out put pin that will output the PWM signal and a common ground.

Most scope leads have a hook clip that goes to the signal pin and some form of clip (eg aligator clip) that connects to a common ground.

if you do a google search there are hundreds of videos that show you how to hook it up in a correct manner for what you are testing.

if in doubt ask your lecturer or another teacher at the uni. scopes are expensive and not something you want to break and have to pay for.

EDIT: you only need to post on 1 board.
Title: Re: help to link with oscilloscope..
Post by: Soeren on March 14, 2011, 11:36:02 AM
Hi,

Tektronix has a good tutorial on using an oscilloscope (http://www.tek.com/cgi-bin/rfbypass.cgi?link=http://www2.tek.com/cmswpt/tidownload.lotr?ct=TI&cs=pri&ci=2280&lc=EN) that you should read