# Search results

1. ### My amplifier -- why did this capacitor blow in my guitar amp?

Your capacitor probably failed due to age
2. ### Source strangulation for an instant water heater?

As an electronics tech I suggest actually measuring the resistance of the plumbing. I’d use a static test of pressure with no water flowing, and a further measurement with the tap fully ON. Does that make sense to the fluid dynamics guys?
3. ### DB scale misunderstanding

Attenuation is measured in dB; so that for example a level of -10dB is the outcome when a signal at a level of 0dB is attenuated by a factor of ten. :)
4. ### I Number of gravitons detected

So gravitational waves are waves of electromagnetic energy which come from some direction, weakly interact with matter, and move on. You'd think that a massive sphere (say a planet) would focus gravitational waves much as a glass sphere focuses visible light, so that at some distance a...
5. ### I Why do rockets turn horizontally so soon after launch?

Possibly, the fact that the Earth is rotating away from the rocket's launch point makes it seem to turn to the horizontal, when it's actually moving in a straight line.
6. ### I A perfectly stiff wheel cannot roll on a stiff floor?

Hi :-) This question reminds me of the problem that ancient mathematicians had with Achilles and the Tortoise, because their problem required the expansion of mathematical understanding to encompass the calculus - in other words the paradigm within which they attempted to get a grip on the...
7. ### What are the 'best of the best' textbooks to help me learn math from the ground up?

I really liked those books too. The "College Algebra, with 1720 solved problems" if I remember correctly, was such a big help.
8. ### What are the 'best of the best' textbooks to help me learn math from the ground up?

Hi :) I have found that the best teaching resources are at New Zealand/Australian "4th Form" level. Almost any modern book will do. Usually, the most trouble people have is learning the meaning of division. Good luck, and feel free to PM me if you have any further questions. Mark
9. ### Lazer but with sound?

maybe this could be done with powdered or gaseous chemistry
10. ### Coherence distance in lasers

Thanks for your question Ranger Mike :) I have very little money, being a pensioner. The design I'm using is one I cooked up for myself in the olden days (ended last week) when I believed that lasers just continuously lased, and did not continually restart as seems to be the case.
11. ### Coherence distance in lasers

Hi people :) I want to build an interferometer. In the course of looking for a suitable light source for my instrument I have been advised to check the 'coherence distance' of the sources; it is clear to me that this distance places practical limits on the design of the machine. However...
12. ### How to get teh closest Metal object

Hi Litup! :-) are you still looking for ideas? I suggest ultrasonic 'radar'. You could pulse a burst of 40kHz sound, time the received signals, and locate the nearest item using Arduino. I hear that the Arduino platform is very good for this kind of work, and is very cheap. There will be a...
13. ### Any ideas how I could fill a steel tube with pellets?

... or the pellets could be swept up from the bottom of the tube by air moving towards a partial vacuum at the top, or Lester's "2)" could use air pressure instead of a ramrod
14. ### Recording sound without microphone

I have heard that there are often conflicts when a soundcard is used for both input and output simultaneously. I might look for a way to resolve those conflicts or include a second soundcard. I found this: http://chipmusic.org/forums/topic/638/lsdj-to-mp3/ which may help... :-D
15. ### Monochrome interference microphone

Further question: I've been turning this over and over in my mind and I just don't see why a laser should be required. It seems to me that a Young's double slit should work just as well, with no dangerous lasers. Perhaps I got that wrong?
16. ### Monochrome interference microphone

Thanks Berkeman! Still, I'm sure the professional systems use more than 1 detector, otherwise they wouldn't be able to detect the sense of any movement - whether it is towards or away from the detector. I've made a small advance in understanding. If just 2 detectors are 1/4 wavelength apart the...
17. ### Monochrome interference microphone

Idea for a microphone. Hi People! I've had an idea for a monochrome light microphone, which I have rendered as a drawing, attached. The detector consists of a monochrome source (l.e.d.), a reflective membrane (gold leaf) some distance from the source, a static reflective...
18. ### The amplitude of EM radiation

I suggest the ARRL Handbook, which provides quite accessible explanations.
19. ### The amplitude of EM radiation

Hi "Disconnected" :-) what level of question is this, please? If you want to know about how amplitude modulated signals are generated that's not so hard for me to answer - the voltage fed to the aerial is modulated by electronic circuits so that more or less energy is fed to the aerial. I can...
20. ### Laser light interference on liquid metal. why?

Perhaps impurities in the Gallium are causing a microscopic lumpiness in the surface of the droplet? That would give several reflections a chance to be cast onto the one point on your wall. If this is so you might be able to find a way to push the impurities around and so change the pattern...
21. ### Falling into a black hole and then shining a light?

Hi People Could a black hole have a region of "normal" space inside it?
22. ### Single Slit experiment for Soundwaves; intensity dependant on wavelength or amplitude

Hi again Blake 2 I still think that resonance may be an important part of the phenomenon. Imagine that a single-frequency sound is being generated by a single speaker in a room with a slit. If the walls are reflective of sound, there will usually be a path for sound to bounce around the...
23. ### Single Slit experiment for Soundwaves; intensity dependant on wavelength or amplitude

Just to point out that the room in which the loudspeakers are sited may have a resonance which affects the amount of sound available to pass through the door/slit.
24. ### Fuse Tap Circuit Problem (easy?)

Hi! I don't understand the drawing, which shows a connection to +12V but no connection to Earth. I'll attach a drawing more like what I would expect...
25. ### Resistor to trick 12v transformer

Hi I have an excellent test-equipment design I want to share with you because it will enable you to track down your fault. It needs parts : 2 of 12v filament lamps; a mounting arrangement for the lamps, and a probe. Oh, and red and blue paint. Connect the 2 lamps in series, and connect the...
26. ### Nodal analysis with TI-84

Scilab is also a very capable Matlab-like suite developed by a huge French Government team. It's FREE! and very well supported.
27. ### Removing a DC Offset from a Square Wave Signal

Perhaps op-amps would be a good thing for you to look at more carefully. With op-amps, all kinds of mathematical OP-erations can be realised, hence their name. Integration of a voltage wrt time is easy with op-amps, all you do is convert a voltage to a current and collect the charge on a capacitor.
28. ### Basic Questions over the function of Logic Gates

You seem to be asking whether lots of inputs can be logically combined to give a single output. The answer to that question is "Yes"'. Ripple-through logic is an important method of machine control, though it has largely been superceded by microprocessors.
29. ### Simulation of rate equation

I'm not sure whether Matlab requires that you define your variables before attempting to execute them, but I see that line 4, for example, (I0 = N0*q*Va/Tn;) contains several variables you do not define until later in your routine.
30. ### Ferris Wheel trig question

Sometimes a diagram of the problem helps visualise the solution. Draw the ferris wheel, add a line 125 feet off the ground, and find out what angle of rotation will bring the passenger to that height. I have to stop now, and leave you with something to do!