abizar

does the voltage divider maintain the accuracy? But agree the standard circuit is good enough.

Yes, I did do that, will post pictures of the different spectra in a day or so.

gracias

You wont be able to use ground it will create a short. You can only connect across the negative -12V which is now a virtual ground and +5V which is now +17V. If you connect a voltmeter across the -12V (negative/black probe) and the +5V (positive/red probe) you will read +17V. The 460W power supply my have a newer scheme of sensing current on the 3.3V. Do you have a picture of the big plug with many wires? Look for two wires connected to the same hole in the plug. The thinner wire is the sense wire. Try connecting this thin wire to the 220 ohm resistor and then to 0V.

11.8V is within the spec of these power supplies

Designed new conversions scales for weight, volume, linear dimensions etc that can be printed on to the back of the circular slide rule. Uploaded two versions of PDF file for these. They are scaled for 8 inches diameter circle.

Finally made one with thinner plastics and more elaborate scales. Filer for a laser cutter can be downloaded from my instructable.

Thanks for the nice write-up. Question, how do I attach sights to the rule/adilade?and are they needed?

Let me check it again. Will shoot a movie of the whole process so might make it a bit clearer. At that time I had used the cheapest paper. Will send you a heads up after repeating the process.

The hollow lid may have been designed as an insulator, similar to a vacuum flask.

Thank you for publishing that circuit more than 20 years ago! I am using this circuit to control an RGBW High power LED for a microscope light, simple and useful.

Yes, they should be simple to incorporate into a motion sensor - you could connect a bulb base that converts to a plug (bulb to plug adapter) to where th lamp is attached to the motion sensor unit and then connect this LED circuit to the plug.

Glad you liked it. Will try to put some instructables on how we use this for DNA analysis. For the dyes, the comemrcial ones avaiable on ebay are quite good.

Glad you did write the article. It is a simple reliable circuit. Thanks for triggering this project.

that's a tough one, you would need to have really low temperatures, -60C or -80C and then a cold trap to keep the moisture from getting into the vacuum pump.

This is an incredibly educational project. Congratulations. Question: Would it be possible to duplicate this taking a different approach? Uniform light source on top or grid of 96 LEDs, a web-cam or old cell phone taking a picture from the bottom, and then an image analysis module (like ImageJ) to process the whole image and produce an excel table of values?

Exactly!

Thanks. Not sure that this is accurate enough for temperature calibration. I did compare with an old high quality mercury thermometer, like the kind they no longer make!

When you are working with biological stuff like cells, enzymes, DNA, you perform reactions such as attaching one piece of DNA to another. These reactions occur at specific temperatures and in small plastic test tubes, therefore this little system to keep those tubes at the right temperature.

Have been using it for human tissue cultures with BSL1 cell lines (fibroblasts and cancer cell lines). The bottom perforated area is partially covered with a stainless steel tray to keep spills etc under control. This results in increased flow rates around the tray.

The gel is transparent but a fluorescent dye inside the gel sticks to the DNA racing inside the gel towards the positive voltage (DNA loves positives!). The dye + DNA complex lights up when hit with blue light. The transilluminator only allows the orangish color from the Dye/DNA to come through and blocks the blue light so you can see those "invisible" molecules of DNA. Magic!

not sure how to measure lumens, but led datasheets may have lumens vs mA ... will check

did some more modifications. Lowered the glass panels by 2 inches so the bottom gap is about 4 inches. Added an LED lamp and two uvc bulbs. Did quite a bit of sterility testing after sterilizing the cabinet with formalin and it does maintain sterile conditions when tested with Bacterial growth media placed inside the cabinet.

Well you are a bit behind - folks have sequenced the big foot genome.http://sasquatchgenomeproject.org/

This ATX PSU did not need a power resistor across the output. Don't know why ...?The 5 and 3.3 V outputs are well regulated unlike the earlier version where without the power resistor the PSU would come on for a while and then shut off.I do miss having an ammeter for the fixed voltages too like I did for the older ATX PSU so most likely will add one sometime in the near future.

Not that complex. Many make something similar. Main difference, I used better speed control than some.

I did make a better quality version of my tool drawer chest for the wife. Better wood, better finish, used pre-made spherical wooden fence-post tops as feet. Drawers have black felt lining ... Top 6 drawers she uses for jewelry (she loves jewelry!). One of the drawers is for her fashion watches. Bottom drawers are underwear, etc.

I like your ambition. Only problem, somehow the stupidly simple projects end up getting done before the stupidly complex. Am guessing #13 and #17 on your list are quite complex, so ...

agree. Had seen Marius video a while back and did like the idea. Mathias Wandelhad done something similar. But building a hundred plus boxes scared me! Will try it for one of the drawers and post an update. BTW, a significant advantage of really wide drawers is that you find things more quickly as compared to opening many small drawers. Maybe I should have tried the 8 ft wide drawers!