Search found 24 matches

by rocket scientist
Mon Jan 31, 2005 7:30 pm
Forum: General Discussion
Topic: Lighted Hockey Puck
Replies: 32
Views: 7091

Re: Lighted Hockey Puck

Pond Hockey! I am impressed. I can't imagine playing hockey where the air is colder than the ice. <p>If, you are going to go the electric route, have you thought about what you are going to do with all those high tech pucks with dead batteries. Seems like the technique for recharging (or replacing) ...
by rocket scientist
Mon Jan 31, 2005 6:57 pm
Forum: General Discussion
Topic: electronics knowlege at BSEE level
Replies: 12
Views: 2953

Re: electronics knowlege at BSEE level

Hi no_vice<p>These kids out of college are not even close to what you are talking about. I think the reason is that electronics was never their hobby. As a result they have no experience going into school, and almost none coming out. Also, EE is now a profession that is all over the map, and I would...
by rocket scientist
Sun Jan 30, 2005 10:46 pm
Forum: General Discussion
Topic: electronics knowlege at BSEE level
Replies: 12
Views: 2953

Re: electronics knowlege at BSEE level

All of the above feedback is very useful. Sounds like you guys would make great interviewers. I will try to incorporate these ideas in the next round. Thanks.
by rocket scientist
Sun Jan 30, 2005 12:05 am
Forum: General Discussion
Topic: electronics knowlege at BSEE level
Replies: 12
Views: 2953

electronics knowlege at BSEE level

I have recently been interviewing candidates for an entry level E.E. position at my company. I ask simple electronics questions to evaluate candidates. What I find is that what I think are simple questions stump almost all of them. These are students with four years of college training in EE, so I a...
by rocket scientist
Sat Jan 29, 2005 11:47 pm
Forum: General Discussion
Topic: Lighted Hockey Puck
Replies: 32
Views: 7091

Re: Lighted Hockey Puck

A big question that I am surprised no one has asked is -- what are you going to do with it? Is it an ice hockey puck or a roller puck, and are you going to play hockey with it. If so, is it mini-mite hockey or NHL? There are some very difficult environmetnal considerations to design around. <p>By th...
by rocket scientist
Wed Jan 19, 2005 3:10 pm
Forum: General Discussion
Topic: EM Waves / Particles
Replies: 16
Views: 4038

Re: EM Waves / Particles

Smith: The accurate statement is that 'every action has an equal and OPPOSITE reaction', which I certainly won't argue with. What could this possibly have to do with the E an M fields being at 90 degrees to each other? If nothing else, at 90 deg they are not even opposite -- oppostie is 180 degrees.
by rocket scientist
Wed Jan 19, 2005 2:25 pm
Forum: General Discussion
Topic: EM Waves / Particles
Replies: 16
Views: 4038

Re: EM Waves / Particles

I am not sure what the original question was, and I am having trouble understanding what questions the above answers are in response to. <p>If you REALLY want to nderstand E&M, you will have to get into quantum electrodynamics (QED), developed by Richard Feynman and others. <p>Short of gettinng into...
by rocket scientist
Mon Jan 10, 2005 5:53 pm
Forum: General Discussion
Topic: Sonar in a chip? I think I need a PIC programer....
Replies: 26
Views: 6739

Re: Sonar in a chip? I think I need a PIC programer....

Don't give up yet. I have used my soundblaster for research quality, calibrated sound measurements, and I have never seen anything that looks like and AGC effect. Where did you get this information?<p>Also, if you patent, you know you will have to include all of us as joint inventors. That is why we...
by rocket scientist
Mon Jan 10, 2005 2:42 pm
Forum: General Discussion
Topic: Sonar in a chip? I think I need a PIC programer....
Replies: 26
Views: 6739

Re: Sonar in a chip? I think I need a PIC programer....

As long as the mic is acoutic noise limited, not self noise limited, it is good enough. I have never found the inexpensive ECM's that you find all over the place lacking in this respect (e.g. the Panasonic WM-64).<p>I think Tinkerer wanted to generate an echo as funciton of range as one would in a s...
by rocket scientist
Sun Jan 09, 2005 4:11 pm
Forum: General Discussion
Topic: Sonar in a chip? I think I need a PIC programer....
Replies: 26
Views: 6739

Re: Sonar in a chip? I think I need a PIC programer....

Sounds cards are great digitizers for frequencies up to 20 kHz. You will probably get a good 12 bits of dynamic range from a 16 bit card. You can send your tranmit pulse to the audio channel to provide a time stamp to syncronize your audio channel with the TX. I am almostsure you can read the sound ...
by rocket scientist
Sun Jan 09, 2005 3:50 pm
Forum: General Discussion
Topic: Impedance match
Replies: 2
Views: 871

Re: Impedance match

I don't know your application or this chip, but I assume this is an A/D chip. Typically A/D chips are very high impedance -- much higher than what you measured.<p>Also, you should be clear as to why you are trying to match impedances. One reason is to maximize power transfer to a load. However, for ...
by rocket scientist
Sun Jan 09, 2005 3:11 pm
Forum: General Discussion
Topic: Sonar in a chip? I think I need a PIC programer....
Replies: 26
Views: 6739

Re: Sonar in a chip? I think I need a PIC programer....

I have done quite a bit of work with TX adn RX of sound. The first thing I wonder about is what you mean by 'chirp'. Chirp normally means (in both sonar and radar literature) a frequncy sweep, which allows you to get, simultaneously,long pulses for increased TX energy and high bandwidth for high spa...
by rocket scientist
Sat Jan 08, 2005 4:19 pm
Forum: General Discussion
Topic: Charging a coil
Replies: 25
Views: 5118

Re: Charging a coil

There have been a few good math questions asked that have not been answered yet, so I will take a try. <p>The differential equation, V = L * di/dt, that Engineer1138 proposed is correct, but he solved it assuming that V is constant. V is not constant, but depends linearly on i through the other impe...
by rocket scientist
Fri Jan 07, 2005 5:42 pm
Forum: General Discussion
Topic: Zener Diode Question
Replies: 10
Views: 2568

Re: Zener Diode Question

Yikes! Good point. Do you think an RC lowpass would work? Then he would just have to find a nice big eletrolyte capacitor.
by rocket scientist
Fri Jan 07, 2005 4:51 pm
Forum: General Discussion
Topic: Zener Diode Question
Replies: 10
Views: 2568

Re: Zener Diode Question

Given that, you have to design for the worst case. 180 Ohms will allow for an input voltage of over just over 35 Volts while keeping the diode current below 30 mA. You may be able to use a much bigger resistor, but keep in mind your load ( the 5V regulator) will 'see' the resistor when the diode vol...