Posted by Justin on May 17, 2012 – 5:00 am
Awhile back, I had recieved an oscilloscope from someone. a Conar model 255 solid state oscilloscope.
It worked ok but I couldnt trust the readings from it or even the voltages it displayed. I could get basic wave forms displayed and thats all I really needed it for. As time went on it started acting up. Certain setings would not display, simple sqaure waves had major overshoot …… I could go on with so many of the issues that started to appear. So today I sat down and did the calibration from the manual. What a pain.
total time spent on it was about an hour and I did the best I could.
I still need need to buy 2x LM733 and a 741 or a better drop in replacement, also a few capacitors and transistors. But those will have to wait till I am employed again.
here are a few pics of the internals
Posted by Justin on May 5, 2012 – 11:18 am
I was given an Altec Lansing VS2121 powered speaker sytem that was going bad. And I wanted to recycle some of the parts out of it. What I found inside was quite interesting.
Here is what I found,
2 x lm324 quad op amp from st
2 x tfa9842j single chip 2 channel amp
and a whole bunch of passive through hole parts (caps, resistors) .
It is a very simple design. Now I have some decent op amps and a decent size transformer (120v to 15.3v 1.6A) with a nice particle board box.
Time to start thinking of what I can remake this into.
Happy Hacking!
Posted by Justin on January 27, 2012 – 6:39 pm
I really needed a quick amplifier to power a few book shelf speakers. Looking around my ic bin, I found a few lm386s.
Next I pulled the rest of the parts (1x perf board, 2x ic sockets, 2x 100uf caps, 2x 5k pots, some wires, and a few odds and ends)
Put all this in a blender, bake for few hours and this is what you get.
The results are, its not a bad sound. some noticeable distortion at higher levels. More improvements can be made, like changing the output caps to bigger ones, adding a gain selector….etc.
But what I have now works. Next a class A amp and other projects.
Posted by Justin on January 17, 2012 – 8:08 pm
Most of the motor wiring done. tomorrow I will test the motors and to make sure there are no shorts or other issues.
Posted by Justin on January 13, 2012 – 2:48 pm
Hopefully this will help me stay motivated to keep posting. my current side project
My motor driver should be done this weekend.
