Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Anyone know anything about PWM?

Status
Not open for further replies.

Callo1234

New Member
Hi

Im about to start a project on it and want to put some background into my introduction which i have to do before doing the practical.

I have hypothesised on most of the experiments im going to do but im unsure what to predict on this...

Using pwm to encode an audio signal into digital form in order to send it down a fibre optic link and decode it using a filter.

You will connect an mp3 into a headphone socket AUDIO IN, set SW1 to AUDIO IN and SW2 to DIRECT etc. Connect your headphones to AUDIO OUT.

(a) Observe the waveform as the music chnages between quieter and louder passages and see the movement of the waveform. What do you think will happen and why is this happening?

(b) Using a fibre optic transmitter and reciever you will send a signal down a 1m cable. A filter will convert the digital signal back to an analouge one..

If you unplug the fibre optic cable from the receiver, the filter input disappeers. The light output should be glowing red. Now vary the dc potentiometer and observe the light output . What do you observe and why? (Can you explian what is providing the filtering action here? Hint- think why movie films dont flicker despite being made up of individual frames.
 

crutschow

Well-Known Member
Most Helpful Member
Sounds like a homework assignment.
You'll have to do a little more than just pass the questions along.
Do you know what pwm is?
What are your hypotheses?
 
Last edited:
Status
Not open for further replies.

EE World Online Articles

Loading
Top