Posted: 3/28/2005 4:24:01 PM EDT
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Ok electronics fans a little help would be greatly appreciated. In lab we set up s five stage ring oscillator and found the propegation delay time. WTH is the propegation delay time and why do we care? Trying to write a lab report and having problems. We were given a different teacher in a different section because the administration was clued into how bad of a teacher he was. This was something he didn't cover. Can tell the rest of the story some other time. |
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If you ever work with satelite communications you may need to know about it, especialy if you are using multiplexing equipment. Maybe useful in the IT field. I wasn't a radar tech but it seems like it would be important there as well. I work with PLC's on automated machines and RF power supplies for for induction hardening equipment now. I haven't touched anything other than a CB since I got out of the Navy, and propagation delay is about as worthless as teats on a boar hog to me now. propagation delay: elapsed time from xmission to reception (plus a bunch of other fancy words) |
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It's been a whole bunch of years but the principles are still there (I think) Signals always have propagation delay. There is always a time delay even in a simple copper wire. Every circuit has a reaction time. Your ring oscillator has lots and lots of time constants and the feedback has to hit the input to reinforce the input signal. There's always a bit of phase shift due to the delays. Old Eli the Iceman. Now propegation delay means the spread of a virus or other data vector thru a network to me. |
The propagation delay time is how long it takes a signal at the input of the ring to reach the output. It's important because it determines what frequency the oscillator runs at – the shorter the delay, the quicker a signal makes it through the ring, and thus the higher the frequency the oscillator runs at. You can design the oscillator to run at any desired frequency, simply by choosing the proper delay time. |
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You need to understand propagation delay because if you are trying to sync up two autonomous devices that are clocked seperately, that delay factor must be consider a component of the timing. This is seen in radio or wire communications. If you dont plan to be an engineer, then it probably isnt that important for you. If you have elected engineering as a profession, you may want to spend some more time on it. Its one of those things that perspective will teach you...stepping back and seeing the complete project, not just a component of the overall circuit. Good luck on the lab |
| Well, if you need any more help I am sure there are plenty of brains to pick around here. I am a satellite communications/electronics technician and there are probably a lot of EE's and such around here. Helping people answer questions is actually a good way to make sure I have the principles of a certain thing cemented in my head, especially if I haven't used it in some time. |