Log in

No account? Create an account

Altoid-O-Scope adapter.

    Due to my recent interest in audio-projects, I've found myself wanting access to a simple o-scope. Luckily, there are a great number of good(free) soundcard-scope apps for the pc.  And since my primary concern is waveforms not specific voltage info I dont have to build any fancy hardware to use 'em!   that said I did slap together this little adapter out of an altoid tin, a linear pot, and a coupla jacks.  as you'll see in the pictures there's not much to it, but it still provides my soundcard some protection from excessive currents 'n such...  and when using a coax rca cable as a probe, there's very little noise.  the only thing I'd like to add is another ground terminal so that i could have the groound line not pass through the pc. anyway here are the pics.
Altoid-O-Scope Adapter 3/4 view The inside

12AX7/12AU7 Headphone amp building

Well I finished my first build of a 12AX7/12AU7 headphone amp of course it doesnt actually work , but it turns on without catching fire and that's a good start.
See? the powers on, and no magic smoke's escaping... of course it's also not making any noise at all. I have my tealight music generator plugged into it's input, yet sadly not a peep comes from the tiny laptop speakers i have plugged into it.

the tube's filaments heat up tho (at least it does something)
See the glowing orange bits?

tube headphone amp


well I've started work on a copy of the 12AU7 Tube / IRF612 MOSFET Hybrid Headphone Amplifier though it'll probably be a while as the universe seems to think i should never find any caps that i actually could use. still i made a cute little resistor flower out of the 100, 100k, and :eek: SONOFA! guess who grabbed 2 22k resistors instead of 2.2K :bawling: guess I'll be adding to more petals to it soon.. sigh guess i should be glad i dont have to rework the whole thing... anyway just sharing the first of what i'm sure will be many mistakes.

what i learned so far... always QUADRUPLE check your part values before reaching for the soldering iron !

Pinnacle MovieBox USB powersupply

      More than a year ago now I found and purchased a Pinnacle MovieBox USB at my local goodwill (without a power supply of course). Recently, i stumbled across it while picking up the clutter in my home, and decided it was time to either make it work or toss it.  

The internet seems to agree its power supply is 3.3V at 3AMPS and posative tip (though the packaging claims 1.5 amps for some reason)

That said, I was able to get mine to work quite well..  with a panasonic 5V 2A power supply (I suppose according to my laws of Ohms law approximation it's about the same (2V=1A right? (listens for electronics engineers heads exploding)) (NOTE: Do not try a 5V 1A zip drive powersupply as i first did, it will get INSANELY hot)

The software it comes with works fairly well for being so old, and so far I've used it to make mpg files of 2 vhs tapes. 

so I guess it works, still I should probably purchase a 3.3 volt power supply for it someday as pinnacle decided voltage regulators cost too much to include on a pcb (see pic). and some of the IC's they use aren't rated for anything higher than 3.3V.

(as you can see Pinnacle cheaped out on voltage regs and only used one, where absolutely necessary)

anyway here are some datasheets for some of its prominent IC's.
CY7C68013.pdf  XC9572.pdf  EM638325.pdf   saa7114h.pdf

motors and Alternate(or) energy

A friend who's interested in wind power asked me to keep an eye out for motors he could use as generators in a DIY wind turbine.  so far this is what i've scraped together.
First is a 6-volt motor i think i pulled out of an OLD tape machine it's small but has STRONG magnets (you can feel them pulling as you turn the rotor) and it already has a small uh ?pully? for a drive belt.(see the picture)

Second is an old floppy motor, the only one i have at my house is torn apart, but i have lots of 'em in storage. as you'll see in the picture its pretty simple, it's a two or 3 step stepper motor.

  I was thinking even if you don't use the fairly weak magnet ring the floppy motor has, you could pull the coil rings from a few , and wire em together as the core for a homebuilt generator.. a stack of 6 inside a spinning cylinder with rare earth magnets attached to it's interior otta make for a fairly good current output.


HAPPY,....uh yeah...

    I remember a time when I could afford to buy things after getting paid :P    

    I'm 2 MOSFETs and an odd capacitor or 2 from having everything i need for my first tube project, but sadly i just cant afford them right now. I need two IR612 MOSFETs I have a bunch of IR512, IR530's in my parts bin but no 612's   I'd try subbing the 512's for the 612's (as far as i can tell it should be fine unless i REALLY crank the volume) but I cant afford 2 components right now, I REALLY cant afford to replace everything that might be fried by using the wrong components :P

  Anyhoo, since I've been kinda frustrated by all the sniggly little setbacks in my tube and handset projects, I thought I'd whip together a "sure thing". I found a simple "
throbbing LED" project..  (i'm sure most of you have already guessed where this is going)  . So this should be easy.. I dont have to figure anything out, just follow the directions and build right?  since i wanted "easy" i even splurged on some Radioshack prefboardy thingis to make it easier to asseble :P   anyhoo if you go to the page i went to, and look at the pics/schematics i did you'll see they use ONE polarized Cap........ RIIIGGHHTTT..   after hours of swearing and re-rechecking the connections.. and resoldering till the perf-board was shorted out and useless..  I decided i should try using my brain... the polarized cap didn't make much sense to me but the picture showed it working right? :P lol...   long-story short, I hate the web, and i dont have any throbby LEDS.

Tubes and Electrons!

  Am looking into building a simple tube preamp for my stereo, I'm so tired of people saying "Digital" like it means "better"  not everything in life is square.. ESPECIALLY sound waves.  anyway I've ordered some 12AX7 tubes and a 6AX5GT and will try to slap something together before newyears.   

 I have alot of rambling thoughts on DigitalVsAnalog arguments.. as well as some things to say about people who insist on only "audio" quality tubes... but i'm tired right now..  so suffice to say that as always, i feel the truth is somewhere in the middle :)

oh, and my phone-handset project is going on the backburner for a bit, for now I've just stuck a modern mic in place of the carbon-crud mic so i have a handset i can use, though it's not as lusciously retro as i'd prefer ^_^;

Old Telephone Handset Conversion

For the past few days I've been working on converting an OLD telephone handset to plug into my headphone and misc jacks on my P.C. Sounds easy right? :P well between my lack of electronics experience, my insisting to use original hardware (basically am making an adapter to plug it into rather than replacing the internals of the handset), and my misplacing of every breadboard i own (hell, it took me a full day to even find my multimeter); this is fast becoming an epic project.

The earpiece is pretty straightforward, basically it can plug right in to the headphone jack (after being attached to a 1/8" jack), might add a variable resistor for volume control though.

The microphone bit, that's the tough bit... at first I just thought it needed amplification, it does provide a signal, just a very weak one. Further research indicated that what it actually needed was power, line voltage to be precise (a bit less than one volt). This could be supplied by a single AA/AAA battery with a resistor, but I chose to go a more difficult rout for a few reasons; one, as the battery ran down performance would change; two, I wanted to do this project with parts I already had/scraps and i don't have any AA battery trays; Three, who wants to have ANOTHER battery to change?

For those reasons i set about building an adapter to step down 5v from USB to .7 volts. This is the part i wish i had a breadboard for, luckily I was able make a small breadboard from an old IDE cable but this added allot of time to the project. Breadboard assembled, I used two 500 ohm variable resistors and an amber LED to get the output I wanted. (yes I probably could have used regular resistors, but I would have had to make a much larger breadboard, and I have ALLOT of variable resistors in my parts bin.)

Once I finally had my voltage regulator made, I was done for the day (too much frustration and soldering-iron burns to continue). So today I'll assemble the prototype version, I'll post the results + more detailed plans once it's complete.

- Nov 25 2008

   *sigh* nothings ever simple: 

    The two handets I've been using seem to have completely different pin-outs on their mini rj-11 (ok thats probably not the jacks name, but you know what I mean right?, the one that connects the handset to the phone.)    The first handset uses pins 1&2 for the mic, 3&4 for the earpiece  the second  uses 1&4 for the mic, 2&3 for the earpiece...

     The google research i did, suggested providing 1 to .7 volts to run the mic, but when i metered the power being provided by the phone the handset came from, the phone was sending it close to 6V !!  of course since the carbon-crud mic these handsets use works by varying resistance (my meter show .8Kohms in silence or  6 to 7K ohms in a noisy room) I suppose it could still work at .7V but i have doubts seems like you'd only be hear quiet noises.

  Still I guess I'll just plunge forward and give it a shot with my current power-setup and revised pin-out. 

  If I ever get anywhere you'll hear about it here..

What's it all about

      Hmmm... well i guess i should say a bit about what to expect in this site (wont say blog because i hate the word and dont believe it needs to exist).

      I'll be posting my, Oak1780 (AKA Josh Mason), random ideas and inventions as well as source code snippets and bad writing XD

      Over the years I've had alot of ideas for inventions/programs i thought would be neat, but I've never had the follow through to develop them. So from now on I'm gonna post those ideas here so that others might persue them..  (also so i can say "see I though of it first!" when some company releases a product or program i thought of years ago :P )

      All that being said, I'm sure most of my ideas are half-baked, but perhaps some of the bright people on the net can help me put 'em back in the oven till they're finished :)

  later,   Josh

i wonder

hmm..  i wonder if i should  used my real name instead of oak1780, but it has been my handle for  a long time ...  oh well too late to change it now :)