a fidget spinner, a solar cell, compressed air and an oscilloscope - Page 1
Forum section: electronics / general

author: FrankBuss
author_rank: Unknown
timestamp: May 24, 2017, 07:42:23 pm
content: The input is AC coupled. The solar cell is a KXOB22-12X1F. It is pretty fast: When I use it with a PWM controlled flashlight, I can see steep rise and fall times. The test was done with a flashlight in continuous mode as well. Using my ceiling lamp resulted in a terrible 50 Hz noise.

author: FrankBuss
author_rank: Unknown
timestamp: May 24, 2017, 08:27:03 pm
content: I need a high pressure air compressor

author: Red Squirrel
author_rank: Super Contributor
timestamp: May 24, 2017, 09:16:23 pm
content: Haha I've been toying with buying one myself just so I can play with it from an electronics/electrical point of view. Neat experiment with the solar cells.Would be amusing to use that to make an oscillator for a MCU.

author: FrankBuss
author_rank: Unknown
timestamp: May 25, 2017, 04:21:14 am
content: I thought about adding a coin cell, some LEDs and a microcontroller to the fidget spinner itself for a persistence of vision LED thingie (which might need an accelerometer or some other mechanisms to detect a turn) or other experiments.

author: Red Squirrel
author_rank: Super Contributor
timestamp: May 25, 2017, 06:23:47 am
content: Quote from: FrankBuss on May 25, 2017, 04:21:14 amI actually just ordered one, and a rpm meter, I had to join the fad.Had an interesting idea, put magnets on it and create a 3 phase alternator. I'm thinking if you spin it, then apply a load, it will make it slow down faster. Will be a neat display of the laws of conservation of energy. I need to check if any of my nephews are doing a science fair project this year, might be a neat idea for them.

author: German_EE
author_rank: Super Contributor
timestamp: May 25, 2017, 08:10:47 am
content: I saw these fidget spinners for the first time at a flea market last weekend. I just don't get it, they spin around and ............?

author: FrankBuss
author_rank: Unknown
timestamp: May 25, 2017, 09:54:10 am
content: Quote from: German_EE on May 25, 2017, 08:10:47 amIt's the same like a Yoyo. If you are good, you can do some tricks with it:I don't think I could ever spin it on my nose

author: German_EE
author_rank: Super Contributor
timestamp: May 25, 2017, 10:05:25 am
content: OK, I reckon that I'm about fifty years too old for this one, I'll sit it out till the next craze comes along.

author: mgraves235
author_rank: Newbie
timestamp: May 26, 2017, 08:42:19 am
content: be very careful with air pressure around those roller bearings. it's not hard to exceed what they're rated for and they will forcefully eject the rollers or needles at a very high rate of speed. exploding bearings have cause many serious injuries.

author: PointyOintment
author_rank: Frequent Contributor
timestamp: May 27, 2017, 07:40:13 am
content: Quote from: Red Squirrel on May 24, 2017, 09:16:23 pmReminds me of theAlexanderson alternator, which is how high frequencies were produced for radio before electronic oscillators were invented.

author: SeanB
author_rank: Super Contributor
timestamp: May 27, 2017, 09:42:14 am
content: Spinning a bearing with air on your finger can remove it, the bearing will seize solid inner to outer race, and strip your finger to the bone long before it stops. Did see one day on a steel rod, pulled the rod out and it left a hole as it went through the corrugated steel wall. Was only a 6202 bearing as well that was noisy, run up with 10 bar air. We never found it, must still be in the swamp somewhere.However, you do get gyro bearings that are quite willing to run at 100k RPM in use, but those are generally hand polished in both the races and the balls, so they are as flawless as possible, and run with a dry film lubricant in a sealed container so they do not rust.

author: GreyWoolfe
author_rank: Unknown
timestamp: May 27, 2017, 08:08:16 pm
content: Quote from: German_EE on May 25, 2017, 10:05:25 amMe, too.

author: amyk
author_rank: Super Contributor
timestamp: May 28, 2017, 03:45:43 pm
content: Quote from: German_EE on May 25, 2017, 08:10:47 amIMHO it's a clever way for some bearing manufacturers to get rid of and profit from otherwise unusable product.