Search found 82 matches

by jimmy101
Mon Nov 23, 2009 11:38 am
Forum: General Discussion
Topic: The Origin of Life (Electrical)
Replies: 35
Views: 7640

Re: The Origin of Life (Electrical)

You know what else is very interesting: Darwin had no idea about these tiny complex systems when he first came up with his theory. He looked at the whole and came up with a theory to explain that. Could he have been such a good guesser that his theory also applies to very small, tiny things like th...
by jimmy101
Sat Nov 21, 2009 2:58 pm
Forum: General Discussion
Topic: The Origin of Life (Electrical)
Replies: 35
Views: 7640

Re: The Origin of Life (Electrical)

I believe the "all parts must have been created at the same time" part for the flagella "motor" has been pretty well disproved. The various parts (proteins) are all very similar to other proteins with other functions. That implies that the various parts (or precursors to the various parts) existed b...
by jimmy101
Fri Nov 13, 2009 8:19 am
Forum: General Discussion
Topic: Free TV Schematics
Replies: 21
Views: 4989

Re: Free TV Schematics

Have you searched for just the part number without "schematic" (or similar words)? Often you can find the exact problem on the exact set. I've had luck finding things like how to fix bad vertical drive on a 15 year old set with details all they way down to which caps and which chip to replace. (Actu...
by jimmy101
Wed Nov 11, 2009 7:10 am
Forum: General Discussion
Topic: Need a transistor-less, IC-less photocell circuit
Replies: 21
Views: 4567

Re: Need a transistor-less, IC-less photocell circ

Use current through a photocell to turn on a small motor. The motor must perform the next step Is that the exact wording of the challenge? Or do you just have to use a photocell + motor to do the next step? Could the photocell be used to stop an already running motor? That might be easier since you...
by jimmy101
Fri Sep 25, 2009 6:42 am
Forum: General Discussion
Topic: Etchant solution
Replies: 19
Views: 4019

Re: Etchant solution

the hydrogen peroxide is the oxidizing catalyst Actually, it is the oxidizing agent and not a catalyst. The peroxide is consumed during the reaction, a catalyst is not consumed. Peroxide is a stronger oxidizing agent than oxygen (O2). Both are strong enough oxidizing agents to "rust" copper, the pe...
by jimmy101
Thu Sep 24, 2009 12:09 pm
Forum: General Discussion
Topic: Etchant solution
Replies: 19
Views: 4019

Re: Etchant solution

The heat of dilution for 30% H2O2 is pretty small, only about 0.2Kcal/mol. For 30% HCl it's more than ten times bigger at 2.7kcal/mol. So you need to add the HCl to the H2O2. http://www.h2o2.com/intro/properties/thermodynamic.html http://www.jsia.gr.jp/data/handling_02e.pdf For this particular etcha...
by jimmy101
Thu Sep 24, 2009 3:50 am
Forum: General Discussion
Topic: Etchant solution
Replies: 19
Views: 4019

Re: Etchant solution

Always add the acid to the water . 30% HCl is pretty concentrated acid and will generate a fair amount of heat when mixed with water. The hydrogen peroxide is probably 3% so that basically water from a mixing standpoint. Any source that says to add the peroxide to the acid is wrong. Add the acid sl...
by jimmy101
Sun Aug 30, 2009 8:25 am
Forum: General Discussion
Topic: This one evaded me for too long...
Replies: 3
Views: 1016

Re: This one evaded me for too long...

They work just fine, especially in a car environment where "fidelity" is really not all that important. You can also get corded versions that plug into the ear phone jack of your MP3 player then the cassette end goes into the car's player. They work fine as well. The fidelity is about the same as wi...
by jimmy101
Sat Aug 22, 2009 10:55 am
Forum: General Discussion
Topic: lawn mower IGN coils
Replies: 34
Views: 4715

Re: lawn mower IGN coils

As to ignition coils - The max output voltage read is not a practical test. First off, if unloaded, they may quite possibbly arc over and break down internally from abnormally hi voltage. One of the funniest kicks I get is to see JC Whitney, e.g. advertising 40 + KV coils. A normal spark plug will ...
by jimmy101
Sat Aug 22, 2009 10:35 am
Forum: General Discussion
Topic: Stringed Instrument Tuner, Ideas?
Replies: 30
Views: 6211

Re: Stringed Instrument Tuner, Ideas?

Viewing the vibrating string with a strobing LED is certainly good for teaching people how a string instrument works. And how to visualize something that is moving periodically but too fast for the unaided eye to see. I wonder, what is the on / off time for a typical LED? Seems to me that that is go...
by jimmy101
Fri Aug 14, 2009 9:01 am
Forum: General Discussion
Topic: Grill electronic igniter module test
Replies: 3
Views: 1335

Re: Grill electronic igniter module test

Those little igniters typically generate voltage spikes in the range of a few KV up to perhaps 10KV. If the gap(s) is(are) too big it won't work. You can try shortening the width of the gaps and see if that works. Gaps will also work better if one or both of the electrodes are sharp since spark's wi...
by jimmy101
Thu Aug 13, 2009 11:22 am
Forum: General Discussion
Topic: Electron-Volts, a unit of energy?
Replies: 15
Views: 2976

Re: Electron-Volts, a unit of energy?

The only problem is that an electron isn't a particle. At least not when it is present in a conductor. It's a wave function. It doesn't exist at any particular place. "Drift velocity" requires the electron is located at a particular place at a particular time. This is an artifical construct that doe...
by jimmy101
Wed Aug 12, 2009 9:25 am
Forum: General Discussion
Topic: Electron-Volts, a unit of energy?
Replies: 15
Views: 2976

Re: Electron-Volts, a unit of energy?

IIRC, that method of calculating isn't correct. The speed of current through a conductor is basically the speed of light in that material. The electric field propagates at the speed of light. To get an electron "off the end of the wire" you push an electron onto the other end, the field propagates t...
by jimmy101
Thu Aug 06, 2009 9:21 am
Forum: General Discussion
Topic: Electron-Volts, a unit of energy?
Replies: 15
Views: 2976

Re: Electron-Volts, a unit of energy?

Don't geiger counters count actual high energy particle impacts with the counter's detector? What about the person holding the geiger counter and background radiation? Certainly we have high energy particles zooming through our bodies all the time. Apparently there must be a safe limit, with some d...
by jimmy101
Wed Aug 05, 2009 10:41 am
Forum: General Discussion
Topic: Electron-Volts, a unit of energy?
Replies: 15
Views: 2976

Re: Electron-Volts, a unit of energy?

An Electron-Volt is a pretty tiny hunk of energy! 100 million Electron-Volts wouldn't even tickle your tongue. But it may well cause cancer of your tongue. Like haklesup said, it depends on your point of view. 100 million Electron-Volts is about the energy of a single subatomic particle ejected fro...