Ay, 20 mA LED shoots like a bullet :) - Page 1
Forum section: electronics / general

author: Madsaaby
author_rank: Regular Contributor
timestamp: December 23, 2012, 06:48:37 pm
content: Lets pull an amp through a 20 mA LED, just because it's funGo to 2:20 to skip the boring part- Mads

author: PA0PBZ
author_rank: Super Contributor
timestamp: December 23, 2012, 06:51:49 pm
content: "We show you this so you won't have to do it at home"

author: SeanB
author_rank: Super Contributor
timestamp: December 23, 2012, 07:00:24 pm
content: Bond wire vapourised.........

author: Madsaaby
author_rank: Regular Contributor
timestamp: December 24, 2012, 12:17:14 am
content: Quote from: PA0PBZ on December 23, 2012, 06:51:49 pmOr: "Another idea for stuff to try at home!" Heh-Mads

author: Madsaaby
author_rank: Regular Contributor
timestamp: December 24, 2012, 12:19:32 am
content: Quote from: SeanB on December 23, 2012, 07:00:24 pmYup, and it was in a hurry to do so

author: nitro2k01
author_rank: Frequent Contributor
timestamp: December 24, 2012, 03:53:59 am
content: I once connected a 74hc chip the wrong way around. For a few seconds, nothing happened. Then short high pitched noise. A small splinter had been ejected from the chip. If anything, that could have made me blind.

author: Achilles
author_rank: Regular Contributor
timestamp: December 24, 2012, 10:54:20 am
content: Well, not a surprise....for sure. Probably two leads with crocodile clips would have been nicer to blow the LED.... especially for those who WILL try it now at home.....I remember when an OP amp was attached to the wrong polarity at it's supply pins. Our 741's did have a nice crater after that.....well, and didn't work anymore.Yeah yeah....those school days.....

author: SeanB
author_rank: Super Contributor
timestamp: December 24, 2012, 11:27:54 am
content: You know you did it wrong when you blow the can off a TO3 part........... I have done a couple of TO100 cans that left only a set of pins and some glass behind.

author: steve30
author_rank: Frequent Contributor
timestamp: December 24, 2012, 03:58:54 pm
content: I managed to blow an LED up once. It didn't shoot like that though, it just cracked, so the pop could be pulled off.I did manage to make an LM358 glow the other day (accidentally):http://www.flickr.com/photos/36651585@N04/8295881542/#in/photostream.I was deliberately running it from a supply voltage which was too high, so I expected it to fail, but i didn't expect it to melt the breadboard.

author: rollatorwieltje
author_rank: Unknown
timestamp: December 24, 2012, 05:03:42 pm
content: Quote from: SeanB on December 24, 2012, 11:27:54 amNow that must have been an impressive bangI did pop loads of TO220 FETs while expirimenting with coilguns. Especially when you parallel them up, if one goes they all go. FET seems to stand for Fiercely Exploding Transistor

author: bitwelder
author_rank: Super Contributor
timestamp: December 24, 2012, 05:29:37 pm
content: Quote from: steve30 on December 24, 2012, 03:58:54 pmNice parallel bundle of resistors there!

author: nitro2k01
author_rank: Frequent Contributor
timestamp: December 24, 2012, 06:16:53 pm
content: Nice bunch of 10 ohm resistors, but that 22 ohm resistor sticks out like a sore thumb...

author: LaurenceW
author_rank: Frequent Contributor
timestamp: December 24, 2012, 06:39:41 pm
content: erm, the lesson I take from this is how impossibly fiddly it is to set voltage and current limits on an HP digital power supply. Not even a number pad! That hardly feels like a giant leap forward for mankind to me.

author: Madsaaby
author_rank: Regular Contributor
timestamp: December 24, 2012, 09:10:40 pm
content: Quote from: LaurenceW on December 24, 2012, 06:39:41 pmI totally agree with that, one of the things I pointed out when I posted it to another, "Favorite PSU", thread..(I should say that I did only use it 15 min before i shot the video, so was a bit new to me.)But apart from that, it's not easy to beat in my opinion.-Mads

author: steve30
author_rank: Frequent Contributor
timestamp: December 24, 2012, 09:19:11 pm
content: Quote from: nitro2k01 on December 24, 2012, 06:16:53 pmJust one or both of them?9x 10R + 2x 22R in parallel = a pretty decent 1R power resistor.With regards to the HP supply, I'm surprised you can't just twiddle the knob and have to select each digit. Sounds a bit odd. Can't you just set an option for twiddling only?BTW, otherwise looks like a nice PSU though. I like the appearance of the VFDs on the HP/Agilent gear.

author: Madsaaby
author_rank: Regular Contributor
timestamp: December 25, 2012, 04:06:10 am
content: Quote from: steve30 on December 24, 2012, 09:19:11 pmYou can just leave it on, say the first decimal place, and adjust int steps of 100 mV, it then carries over to 1 V etc.But if you set 12.345 V, and turn it down while on the "1v" place it will only go down to 0.345 V, you'll have to go to the lower digits and set these to 0 as well.-Mads