Recent content by Rob Rushworth

We've tried the frequency counter app, and it counts single events while keeping a running total. Starting with the tap of a pencil on a table, it can count the number of taps we make. Volume, ie a hard or soft tap, can affect the count - a hard tap can add more than one to the count, a gentle...

Ok, frequency counter sourced: https://play.google.com/store/apps/details?id=com.keuwl.audiofrequencycounter&hl=en initial settings - these give a single count for our audio signal > threshold level at minimum; noise level at maximum, gate time 1 second, measure = freq, direction = rise...

Hello again. Thanks for the replies - most helpful. In sequence: CWatters - so there is drain, I thought that there must be one somewhere... thanks for the confirmation. The students found an Instructable lyesterday that shows how to permanently attach a racquet to a phone charger and keep it...

Hello. I'm an English language teacher researching the details of a class project; I use projects to develop language skills. I have a background in mechanical engineering but know little to nothing of electrical engineering, hence this post. Questions for members of this forum: Electrical...

Evening, Dave. My first concern when the idea of pointing a laser so far was raised was accurately gaining control of the pointing of the laser, and doing so in a way such that any movement was as repeatable as possible. I'm pretty sure that I won't see reflection of the beam back to the...

Got the aiming device 'finished'. it's untested on a tripod as yet, but works well sat on a 2nd-floor, flat, outdoor wall-top and aiming at distant objects - trees, etc. There's a small backlash movement when moving the laser dot horizontally, and the crosshairs formed by moving the dot...

Evening. Google brought me here. I'm not a physicist, but have been looking into this topic for a while for a school project. First, here's a link to a site claiming 12.7 miles on a 0.5mw, $3, red laser pointer - not only sight, but a voice communication link...