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Conundrum

Sun Jul 17 2011, 07:47PM

Registered Member #96 Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4062

Or use wireless power?

Ought to work, although the losses would be horrendous.

-A

hboy007

Sun Jul 17 2011, 09:44PM

Registered Member #1667 Joined: Sat Aug 30 2008, 09:57PM
Location:
Posts: 374

Conundrum wrote ...

I would try this but both my DLP's have been rendered unconscious by power supply fryage.

If anyone has a use for the modules, PM me. I tried to reverse engineer the pinout but its a total horse when the PSU won't even twitch.

this might work:

unsolder one of the main SMPS transformer pins, trim away a little of the inside of the restring for clearance (this way you can still restore the connections) and take over the primary side with a diy halfbridge. Find a known logic IC on a PCB and take its positive supply rail as a kind of voltage sensing value (feedback loop). That should to some extent restore the supply potential ratios and approximate the original voltage levels.

ps. Thinking about it... maybe hooking the loop to one of the filter capacitors that are monitored by the onboard controller, then cranking up the setpoint voltage until a known (e.g. 5V) rail is stable might be more reasonable

Conundrum

Sun Jul 17 2011, 09:49PM

Registered Member #96 Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4062

Good idea, thanks!

The notes about people driving transformers etc from an audio amplifier got me thinking.

How hard would it be to exploit this hack using a 22 kHz differential signal on the tip and ring of the headphone socket combined with an in-headphone amplifier and filters to generate 7.1ch (bass, forward, rear, centre and dual vibrate) on a pair of headphones without any modification of the host device apart from a relatively minor firmware upgrade?
Most MP3 players already detect headphone presence via impedance so have it turn on and off a few times in a defined pattern to tell the host device that 7.1ch 'phones are plugged in.
This avoids confusion when using an existing headphone set.

Even better, add infrared proximity via vOICe etc so you can have bat-like "vision" in the infrared with both audible and haptic feedback by having the MP3 play the same file over and over to keep the headphone's SMPS running?

Just to be badass, you could even have the same headphones send back their stored EEG data via the existing 3.5mm jack so it could be used for medical purposes (i.e. ambulatory EEG monitoring) with negligible impact on the user.
Storing data on the headphones would be doable and would merely require a driver on the host PC to decode microphone data into USB comms, half duplex only like the old modems but still handy when you want to transfer something small like your stored EEG data.

Comments?
-A

PSCG

Mon Jul 18 2011, 08:53AM

Registered Member #3792 Joined: Sun Mar 27 2011, 06:07PM
Location:
Posts: 136

Built a cesium frequency standard and interface it to a computer for super accurate PC clock timing (i'm trying to do it since i was 14).

Find the parts to construct a nuclear battery to power my mobile phone for infinite time.

Anything crazy that will come into my mind....

Chip Fixes

Tue Jul 19 2011, 04:35AM

Registered Member #3781 Joined: Sat Mar 26 2011, 02:25AM
Location:
Posts: 701

Hey look what I came across while trying to find out if regular ink was conductive

if you buy conductive ink pens you can draw resistive lines on the windshield to defrost it

magnet18

Tue Jul 19 2011, 05:07AM

Registered Member #3766 Joined: Sun Mar 20 2011, 05:39AM
Location:

Posts: 624

I've been thinking about a plasma orchestra, with plasma tweeters, something like this (

for the midrange, and some large teslas for insane base, maybe accompanied by a capacitor discharge if it's the 1812 overture

Conundrum

Tue Jul 19 2011, 07:01AM

Registered Member #96 Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4062

Cesium, schesium. Pah. I want a PC Geiger counter already.
Has to plug into any PC microphone port, and be passively powered.
Having alpha, beta and gamma detection would also be nice, especially if
it also has an internal rechargeable battery and datalogger.

It appears that I might be able to recycle the linear sensor segments from
old HP all-in-one printers to save using an expensive camera, the only
real pain will be digitising such a fast signal on a cheap microcontroller.

Perhaps I can feed back the output of the CCD back into the input and then only
sample it every n clock cycles where n is a multiple of the total pixel number.

If this works, reckon I can send it into EPE as a "Top Tenner" project?

-A

hboy007

Tue Jul 19 2011, 08:17AM

Registered Member #1667 Joined: Sat Aug 30 2008, 09:57PM
Location:
Posts: 374

Conundrum wrote ...

I want a PC Geiger counter already.
Has to plug into any PC microphone port, and be passively powered.

SBM-20 can run off a 1.5ÂµF cap initially charged to 390V for about 5000 seconds when monitoring "uranium glass marble" radiation levels. Why not trickle-charge a 22000ÂµF/6.3V (I found Rint to be 0.045 Ohm for one type) cap and recharge the 1.5ÂµF/630V cap every once in a while? You could even integrate a GM counter into your keyboard, power it off USB and hack the scanner matrix to send the count rate, equivalent dose rate and total dose as an ascii string when a certain key combination is pressed using a simple microcontroller.

/me now exposed to 0.15ÂµSv/h (33.6ÂµSv last 7 days)

ps.: just made a proof of concept video for my thermal IR camera idea:

Conundrum

Tue Jul 19 2011, 06:12PM

Registered Member #96 Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4062

Nice!

SBM20? as in the ones used in my counter?
Cool, will have to try that. I was thinking of something like a lambda diode oscillator (J310+BC212 or similar) as these can draw in the tens of microamps.

I submitted a version of this to EW&WW a wile back and they were impressed that it could drive an LED from 1.5V even if you needed to select the JFETs by manufacturer.

-A

hboy007

Fri Aug 12 2011, 09:50PM

Registered Member #1667 Joined: Sat Aug 30 2008, 09:57PM
Location:
Posts: 374

pack a bunch of 20 of these into a prosthetic hand. I don't know if this has been done already but it's an idea I ran across the first time I saw those piezo squiggle motors. These actuators are super tiny, light-weight, fast and strong. Unfortunately, a set that covers the degrees of freedom of a hand would cost ~10000 Euro. Anyone feel like supporting a good project for the sake of mankind?

Just add some neuronal network software and train it to perform organic motions (yeah, I know the way it sounds doesn't to the difficulty of the task justice)

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