
- Quantumdust commented on ShakeTheFuture's instructable DIY Microwave Kiln | Fuse Glass in Your MicrowaveView Instructable »
- Quantumdust commented on Trevor_DIY's instructable 1 Hour Pallet Coffee Table
- Quantumdust commented on omars2's instructable Simplest 12V to 220V DC to AC Power Inverter DIYView Instructable »
The physics and electrical connections are essentially correct. The project is useless. You obviously have an interest in electronic design. Combine that interest with the time it took to assemble the "circuit" upload the pictures and text to all the various places and you will have enough time to design something interesting and teachable to people actually wanting to make something new that they can be proud to show their friends. Skip the stuff that works for a few minutes and starts a fire.
- Quantumdust commented on djpolymath's instructable Center Finder JigView Instructable »
I needed one of these since about 50 years ago. What took you so long ? :-)
- Quantumdust commented on tanner_tech's instructable Electromagnetic Fidget Spinner AcceleratorView Instructable »
I'm very 'fuzzy' about the point and subject of your memorable text.......
- Quantumdust commented on tanner_tech's instructable Electromagnetic Fidget Spinner AcceleratorView Instructable »
Hey Ed, I'm not trying to be a pain, it's just that after 40+ years in sensor R&D I've developed a few items (I call them my "sweet spots") that will bug me forever. You seem to be one of these very rare people these days that actually understand the math and physics behind what they think they know about. Using today's newest buzzword, " having said that" , the answer to the discussion is that we're both right. The rotational reference frame is the key to the whole thing. Centrifugal is only both fictitious and a reaction force in an inertial frame. Putting yourself in a rotating frame makes the math easier and generates the need for existence of the otherwise fictitious forces to make the analysis work. This silly discussion has been turned over and over …
see more » - Quantumdust commented on tanner_tech's instructable Electromagnetic Fidget Spinner AcceleratorView Instructable »
Great project! Love your lab. Based on the photos and video, you really seem to be talented and know what you're doing (rare). Reminds me of my setup about 50 years ago when I started designing projects. All with vacuum tubes, and I was happy as a bunny when the first transistor was actually available for buying. One small comment re one of your descriptions (think about it and the physics will make perfect sense):You say when talking about gluing the magnets "then a magnet might fly off due to centrifugal force, also known as tangential velocity". What really happens if the glue lets go is the magnet flies off " in the direction of the instantaneous tangential velocity". The glue exerts a centripetal force on the magnet keeping it locked going toward the cen…
see more » - Quantumdust commented on gravityisweak's instructable Coat Hanger Drill BitView Instructable »
be safe and sell your car.....
- Quantumdust commented on Lionel Sear's instructable Joule Thief With Ultra Simple Control of Light OutputView Instructable »
Two comments. The LED connection is not shown in the schematics. In #3, where is the connection that charges the battery from the solar cell?
- Quantumdust commented on lkndave's instructable Remote Control UpdateView Instructable »
Good stuff. Easy fix and, yes, it works much better.
- Quantumdust commented on Chris Project's instructable Variable Voltage Regulator Using the LM317View Instructable »
The circuit does work and is about 100 (give or take) years old.It is good for teaching people that are not familiar with the LM317 how to make it variable. I would strongly suggest, to make the schematic logically obvious, put the input on the left with the +ve on top, -ve (ground) on the bottom and the output on the right, +ve on top, referenced to ground. R1 simply goes from Adj. pin to ground in the middle. Much nicer on the eyes.
- Quantumdust commented on Austin Noble 's instructable Simple and Durable Hydroxy Gas Generator
Two seconds of keystrokes on Google gives instant answers to a LOT of obvious questions that people ask on Instructables :-)Wikipedia: Hydroxy gas: A nickname for oxyhydrogen, a combination of hydrogen and oxygen gas produced from the electrolysis of water
View Instructable »If you don't provide separate containers for the two products evolved you get a mixture in one container. This is obviously what the designer wants from the start. Try reading his description again.
- Quantumdust commented on deba168's instructable Make 4 Useful Things From 9V Dead BatteryView Instructable »
LiPo cells for RC flyers, unless they already have manufactured connections, probably have metal (sometimes Aluminium) tabs that are more forgiving than soldering directly to the battery cases of 18650 and other sizes. Still, LiPo absolute max temperature is rated at 140F/60C. After that they become unstable and a fire hazard.For the record, I've soldered Li-Ion 18650 cells once or twice and got away with it without calling the fire department. Then I did a little study on the chemistry and construction of Li batteries in general. Most people don't take the time to dig into this stuff and simply think that batteries are batteries and some are better than others. Not so. Ask the guys that bought electric skateboards only to have them catch fire under them with only "normal"…
see more » - Quantumdust commented on deba168's instructable Make 4 Useful Things From 9V Dead BatteryView Instructable »
Ideas are good....just a couple of comments. Make sure that you, and especially your kids if they are doing it, are very careful cutting the jacket of the old battery. The chemicals inside are NOT user-friendly and can be nasty or toxic if spilled out.The second not is do NOT EVER solder to Li-Ion batteries with a soldering iron. These cells are not meant to be heated like that. Links are always attached with a spot-welder which does not invade the internals of the cell. If you heat it with solder you may be lucky and nothing will happen except a soldered connection, if you are unlucky you get a thing called thermal runaway where the battery shorts inside, heats up, emits hazardous fumes, catches fire and potentially explodes. Unless you like calling 911, do not do this.