Recent content by Rogue Physicist

Lets separate and clarify two different and important ideas here: (1) The difference between A.C. and D.C. currents (and voltages). (2) The difference between the 'hot' and 'neutral' lines in house-wiring. ---------------------------------------------------- (1) All generated currents...

There are some other sides to it as well: (1) Specifically, the amount of modulation practical (how saturated the carrier is with the audio signal) and the noise floor (the volume range and headroom possible for the audio signal) determine both the sound quality and s/n ratio. Consider also...

LOL I fell off my chair reading this! I had forgotten how much fun can be had on zero dollars. As I recall, one of my first experiments as a 9 year old was to make an electro-magnet by wrapping about eighty turns of lamp-cord around some spikes and plugging it in the wall! I was just lucky...

Hi Morbius: Since this seems to be an area in which you have considerable knowledge, I would like to ask what you think of the hazards of Thorium, as it has been used extensively in the manufacture of radio tubes, for instance in 'thoriated tungsten' emitters. Obviously there are a lot of...

You are best isolating a part of the speaker signal, and having it control another circuit which powers the LEDs. Here are the reasons: 1) "Adding any circuitry will distort the audio signal." This is probably not that important if the impedance of the LED circuit is 100 or more times the...

Examining the pictures you posted does look like industrial electroplating. Another easy way to get this would be electroplating with bismuth. This element naturally has this rainbow coloring on the surface, probably due to natural oxidation. I reproduced similar colors when trying to get...

p.s. if you're not satisfied with the bass response of greeting-card kits try gluing one to a small wood box or shoebox. Use a stiff glue like epoxy.

Well done to all who posted more accurate details and experiences with audio mixing and reenforcement. (Yes there was a typo here and there in my first post. ) Actually, just some cautions I meant to point out in the afterthink: Frequencies between 0.4 Hz (not a typo) and 10 Hz are both...

Other factors help explain the ability to create micro-sized 'spaces' or holes. for instance, many filter designs use fibres which can be quite long or large, but closely packed so that the spaces between are very small. You don't actually have to 'drill' holes that small, and the sizes can be...

A fuse is a good start, in series with the output leads, to prevent excessive current flow: Look up the speed of the fuse, and do some tests too: Sometimes its embarrassing for the special circuit to cleverly protect your fuse by hari kari. If you can't get a fast enough reaction time, you...

One way to expand your algebra skills is to do a couple of chapters of trigonometry from a Pre-Calculus course. Especially good are learning trig substitutions and simplifications so you can get more of a foundation of what is more general about algebraic manipulations and what is specific to...

I think what Bob is asking is how do you jump from variables and simple algebraic expressions to cos and sin functions. Usually, it is best understood geometrically. Take a simple right-angle triangle with the right-angle at the origin of a simple x/y graph (2 dimensions, cartesian...

There is an effect that Einstein is getting at here, and it has more to do with Boltzmann/Maxwell than Blackbody Radiation. The point Einstein is trying to make, and it is very subtle, because the result is subtle, and seems to be poorly understood still, is this: Boltzmann's assumption of a...

The circuit you have shown can be looked at several ways: (1) You can ignore the battery and replace it with an equivalent resistor representing it's internal resistance. Now you can calculate the 'impedance', and since there is no reactive component it is simply resistance with no phase...

Do you like music, TV, audio, radio, building robots, or remote-control? Then Electronics and Electrical Engineering is for you! Do you like programming graphics or computer games, connecting networks, messing with automation? Then Computer Programming is where its at. You can't tell...