Amazon's RDS offerings are really convenient, from the perspective of making snapshots and setting up replication. But, I have never been able to push their default 'SSD' storage past 60MB/s. (PostgreSQL and Mysql) That's terrible. That's less than USB 2, and even some SD cards can do that! Our on-prem can do 180MB/s on spinning rust and around 550MB/s on (obsolete) SATA SSD. If you want anything better on RDS you have to REALLY pay a premium for IOPs and transfer, or pay a premium for way more ram and a ton of caching, in addition to external caching in the rest of your stack. I have not used Aurora on RDS, so I don't have a comparison, but I have my suspicions. It would be pretty easy to just give you a few more MB/s and make it look a whole lot better. Luckily in our case we could optimize things enough that storage performance didn't matter too much. But RDS storage performance is so pitiful that it's seriously worth considering putting your DB on a bare metal box somewhere with NVME storage and just put up with the network latency and get 50 times the storage performance (and more ram and cpu while you're at it ) at a fraction of the price.
We've gone from 480Mb/sec up to 6Gb, 10Gb, now 20Gb, and we still can't use a native USB cable to network two linux boxes. Thunderbolt on Mac has this, and there was a very limited solution for linux that was never production ready. We're still stuck at 1Gb/sec between machines for any networking that isn't cost-prohibitive, impractical, or both. The cables exist, I look forward to the day when I can plug two machines together and run a network between them over this cable. Will this ever happen? Or is this a case of hardware vendors blocking open source so that they don't compete with their own jurassic and overpriced 10Gb products?
Going all the way back to USB 2.0, there is a host-to-host mode in the specification, but it's not implemented in any operating system. The best we can get now is USB3.0 to gigabit dongles, which don't take full advantage of the available speed at all.
USB 3.0 is great for storage, the speed is really nice. Then you find that your bottleneck is gigabit ethernet. Thunderbolt supports network bridging on the mac, but it's not really useable on linux. What are the roadblocks to IP over full-speed USB 3.0 or 3.1 data link? Is it pushback from the network vendors?
We already have the cheap, fast hardware, but we can't take full advantage of it.
Will there be any effort to use this for networking? It's really about time.
Look under Settings/Privacy There is a switch, which reads 'Send Microsoft info about how I write to help us improve typing and writing in the future'
This the collection of keystroke data. They can do anything they want with this. Definitely makes it even more creepy to log in to someplace else on a Windows 10 box.
Another thing which is standard practice is to list all kinds of serious and unlikely reasons they'll use your data, followed by 'or any other legal purpose' which does not mean for some 'legal' matter, which it's meant to sound like, but for ANY purpose which is not SPECIFICALLY ILLEGAL. Which means anything.
You can turn off the keystroke thing, but Microsoft routinely resets preferences, including privacy preferences, when you run an update. So you have to keep checking it and make sure it's off. However, I doubt very much if it matters. You're sending EVERYTHING to Microsoft and they can use it for any purpose.
Hello-
If the 16 port switch is a SMART switch, you can, make the last port a TAGGED port, that carries tagged vlan traffic. Make each of the other ports (except number one) an UNTAGGED vlan. (keep number one stock so you can access the switch!) Maybe reserve one for the windows box. Then, on your computer, run a linux instance with vlans configured, like eth0.2, eth0.3 openwrt would be great for this, you can run it on a little router or a VM. On the linux box, (openwrt) set up address translation with DNAT and SNAT to make the same IP on each of the VLANS appear as a unique IP on the same network as the windows box. (There's a little voodoo because you don't want any routing to happen, since you have several networks with the same address scheme.) Then, you can run upgrades simultaneously to several different IPs on the windows box (if it lets you) and the physical box it goes to will just depend on which port it's plugged in to. This VLAN trick is a great way to fake having a whole bunch of network cards in a single box, even a virtual one. =Rmortyh
I do this sort of thing a lot. I have found that a 160MB hard drive is probably too old to do the sort of autodetect that most USB-ATA adapters require. These were the days of entering the harddrive parameters in setup...
The best bet for this is to get a PCMCIA network card that has PXE boot capability. Or, a PCMCIA card with a supported Etherboot binary on a floppy disk. Then boot into a diskless linux setup over the network, and transfer as needed. My oldest net boot image for this is Redhat 9. You might want an even older one, look at Redhat 5 or Slackware 3.3.
This would be most painless because you can just transfer the whole thing over nfs. No messing around with hard drive parameters or matching up new and old hardware. No dealing with windows and dos network drivers beyond just etherboot, which has always worked great for me.
Note that you can do wonders with the old Slackware 3.3 boot disks, boot.i and net.i, maybe pcmcia.i With a PCMCIA network card and the slackware floppies, you may be able to get to an NFS mount in only two or three floppies and no PXE boot. They're also super handy because they'll detect your hardware in that dinosaur and tell you what it is.
If you stay in DOS land you'll have to zip up everything and transfer it with a terminal program, which works but requires lots of space and takes forever. Also getting networking to work on Windows 3.11 if it wasn't already set up long ago is a big pain and should be avoided.
Best not to mess with the hardware or installed software on it at all. PXE is your friend!!
It's a terrible and impractical idea. There is no need for it, other than app makers and data miners trying to make more money, and the police having a new reason to take your phone. It does not improve on the present system which is already computerized.
But more important, will there soon be laws REQUIRING people to carry a phone?
We use custom scripts, that work very well. They're not very complex. We're SMSing through a third-party provider, which is not my first choice, but it is easy to manage.
This is not, of course, extremely secure, but with all the SMS management credentials kept completely separate, it's pretty good.
It gives us the 'something you have' and 'something you know' requirements. You need the phone. In a very well planned and determined attack they could probably get past this, but there are other measures in place, and it makes it hard enough that if they're that determined, they'll try something else.
You can set up 2nd factor using SMS pretty easily, and have it text you a second password that's good for five minutes. Definitely the cheapest option.
If you make your own token with an arduino and an LCD and a real time clock and a battery you've already paid for the RSA tokens.
'Astrology' means 'the study of stars'. When real scientists began to study stars, this term had already been taken over by crackpots. So, they adopted 'Astronomy' which is the NAMING of stars, because the more correct term now meant something else.
So, really, astronomy should be called astrology, and astrology should be called bunk.
Did any of these people stop to consider that CPNI data is routinely sold by Verizon and all other carriers unless they specifically opt out?
How many Americans who are complaining about this have opted out of the CPNI sharing clause of their contracts?
You are already giving permission, by not opting out, to your wireless and landline carriers to sell your metadata to ANYONE for ANY REASON, including the government, who may buy it on the open market just like anyone else. This data is seldom anonymized, and when it is, you can still search for specific characteristics to find the information of a specific person. And, any entity willing to pay for the information may have it, and it can be bought through a third-party data aggregator who will de-anonymize it and bundle it with plenty of other interesting facts about YOU.
How many people have actually read their terms of service? Have they gone through the arcane process of opting out of the voluntary sharing of CPNI data? (Every year, for each carrier?) Will they now complain that no one warned them? Did they expect their politicians to keep them informed? If the politicians had tried, would they have listened? They didn't care when this became the norm 10 years ago, and now suddenly it's intrusive?
This is what happens when you don't pay attention.
A killer robot costs way more than a human soldier, and is much harder to replace. It will be very interesting when this comes into the equation. Are these really to protect the soldiers? Who will end up protecting whom, and who is more 'expendable'?
Nice 2:45 video with the usual pornography-inspired music track, but no movement. No 'Robot in action', just a disembodied leg on a treadmill.
Not to knock these guys too much, this is really typical of the robot industry right now. You go to a robot show or conference, and all the 'state of the art' robots are sitting there completely lifeless and no one has "permission from management" to turn them on.
Come on guys, if the industry is going to go anywhere you're going to have to ignore your lawyers and put the batteries in! Otherwise, how do we know you're not bluffing?
Hello-
Most larger APC units have an external battery connector on the back. It uses an Anderson connector to connect an external battery pack. Also, you can chain battery packs, to have more than one. The external battery packs are expensive but they can be worth it for this very problem.
There's also the DIY method for VERY long uptime!
At my shop, in the locked cabinet, we have an ancient APC 1400 unit, with the batteries REMOVED, and two wal-mart deep-cycle marine batteries connected to the external connector. The batteries are 24-DC 12Volt, 75 amp hour batteries in series, for 24 volts. (grey connector) We disabled the beeper in the unit (with pliers... YANK) This keeps a rack with 7 computers up for several HOURS.
This worked so well we decided to go one better! In the main closet, with extension cords running to the machines in the rest of the shop, we have a 3000VA APC unit. It has a 48 volt input (blue connector), not 24. On this sucker we put FOUR 27-DC 115 amp hour deep-cycle batteries, again from Wal-mart (best price, sorry) in series, connected to the back of the unit with the external connector. For these I got lucky and found a really nice set of cables.
This sucker powers all the machines outside the rack, as well as some flat panels, and a desk lamp. (So we don't break our necks!)
I was worried that the current would be too much for the charger, but I've run them down and back up again and they're fine. I guess the UPS units are made to handle two or so external battery packs, so they handle the lead-acid jumbos just fine.
We've had these for a few years, and even had the same power outage here in SF that took out 365 Main a few years ago and had no problems. I need to do another plug-pull test, but our loads are not that high and we can get up to eight hours! Again, pull out the beepers or you'll pull out your hair.
Some tips- You need nice, big cables to do this. Also, there are some code issues for large lead-acid batteries, so if you want to be completely legal buy the APC external battery units. If you buy at Wal-mart find some old dead lead batteries before you go or they'll charge you $9 core per unit. They really don't care if it's the same kind of battery, I traded in the old APC Sealed units for the marine batteries ten times as big! Unlike the sealed ones, the deep-cycles are spillable so be careful. I have never had them spill but if you tip them over they will probably spill some acid.
Have fun!
=Rich
P.S. If you want more info on this or pictures, you can email me (public account) at rich underscore humphrey at yahoo
There's a picture of a multimeter, and a lighted bulb, but the panel shown is IN THE DARK! Unless it's on a totally different panel that is in the sun, it's way fake. And, as pointed out, 9volts is trivial, but 18 watts is actually really hard.
Also, the reporter is not energy-literate, but that's not a surprise.
I once showed an artist a calculator running on a lemon battery. Not knowing about CURRENT and POWER, she then went and proposed a project to a museum where a classic Gameboy would run on lemons, and they accepted it. Of course this would take a few thousand lemons! Luckily, it was an art museum, not a science museum. We ended up hiding double-A's inside some of the lemons. (We came clean to anyone smart enough to ask!)
Hello-
I have some experience with this problem. You're right that microcontrollers are too advanced, everyone gets bogged down in the development tools. I also find that most types of IC and transistor circuits where you can't SEE what is happening don't really work out for most kids.
A few kids will get really into it. The next group will 'sort of' get things to work by following the directions, but not understanding what is actually happening. The rest will just sit there while everybody else plays around. They won't even try.
I have found that the basics like lightbulbs, batteries, and switches really get kids excited. They can see what's going on and they understand it and start building on it. Flipping a switch or pressing a button to make something happen is very empowering.
Next, if you can get a hold of some nice relays, especially ones with clear housings, they are really useful for this. It's a switch that turns on another switch. They understand it. (especially with a DPDT knife switch to explain things) Try a reed switch and a magnet, controlling a bulb through a relay. (small switch controls big switch... They learn about current) Let them try the NC contacts. Show them a relay LATCH. Connect the coil through the NC contacts for a relay buzzer. Add a speaker across the coil for a louder buzz. Can you combine these and make a burgler alarm? Show them that a mechanical bell or buzzer is the same as the NC relay buzzer. Next, put a capacitor on the relay coil for a delay. They will UNDERSTAND all this and get into it. And they like the clicking.
This lets them learn by using things they understand like switches and bulbs which are all doing things they can actually see. There are no black boxes at all. Also, a lot of kids want to ignore you and just play. With these parts, they can still make things happen and learn just by messing around. Can they get the relay to click? Make the bulb light up?
I've taught a lot of workshops to beginners and most breadboard type stuff really just confuses them. It seems they have made up their minds in advance that this is something they can't do, it's too hard. With the knife switches, batteries, bulbs and relays, they got really excited. When we added the capacitor they really understood what those did. It seems that this is a necessary first step before you move on to 'black box' parts.
Once you've gotten them there, the next thing is an optoisolator, which is really just a relay. Then they're comfortable with a DIP package, and you can proceed to the 555 and such with the ones you haven't lost. In the meantime, skip all semiconductors completely, except the rectifier diode, which they understand, and maybe the LED (with resistor already soldered on).
As we get better at electronics it becomes more and more difficult to understand what it was like to not know anything about electronics. You try to explain a 555 or op amp and there are a thousand details that you're taking for granted without knowing it. The other person really can't get it without the details, which makes it very hard to teach the subject without losing people. This is why you should go for the basics as much as you can. Let them play in that safe zone and master it and build a foundation before moving on.
Skip Ohm's law and the RC circuits and the math stuff for now. Let 'em turn things on and off. They'll get it.
List: Knife switch, lever switch with roller, button. Reed switch and magnet. Buzzer, bulb, rectifier diode. Clear relays, at least SPDT, DPDT better. Capacitor that can hold the relay on for 1 sec. LED with resistor installed. Speaker with resistor inline (so it can go across the battery without blowing up) . Batteries to match all these (9V or 12V is easiest)
THIS IS the Best Phone EVER!
I have two. They're awesome.
4+ years of continuous use,
3 DAYS of battery on ONE HOUR of charge,
NO features except a flashlight,
EXCELLENT sound and reception.
Tons of free chargers and headsets all over
It's just a phone. It just works.
They let me take it into secure places.
I love it.
The only bummer about this story is that now I'll have trouble getting replacements!
Damn.
At least this only works with the European version...
Most interesting, is there are NO BROWN RECLUSE SPIDERS IN CALIFORNIA!
People will argue that there are, and they know someone whose been bitten, but loxosceles reclusa has only been found a handful of times in California in the last 50 years, all of the cases were isolated, and all were traced to shipments from outside the state. (great page from UC Berkeley prof on this that I can't find now...)
A south american recluse has been spotted in the LA area but is not thought to be established.
There are certainly NONE of these in Manteca.
I can tell you though, that although there are none in San Francisco, people will argue that there are to the point of absurdity, so this is a sort of pet subject of mine about how people are wrong.
However, there are so many Black Widows in the Manteca area that you can find several on a twenty minute walk if you're looking for them. Also, Black widow venom IS a neurotoxin, where recluse venom is not. There are also plenty of scorpions and biting centipedes in the area, but no recluses.
Also, in cases where brown recluse IS confirmed, even in one case of large numbers of them in a family home, there were no bites. They're very rare, and necrosis from a CONFIRMED bite is very rare as well.
Most of what you hear about poisonous spiders, even 'first hand accounts', are simply myths. Real brown recluses and black widows are just not very dangerous to healthy adults, and the brown recluses simply does not exist in most places where people claim to have seen them or claim to have been bitten.
I'm most fascinated by the passion with which people will argue against this, even though it can be confirmed just by checking a few books!
Slashdot Mirror
500 million Spanish speakers can't be wrong.
Amazon's RDS offerings are really convenient, from the perspective of making snapshots and setting up replication. But, I have never been able to push their default 'SSD' storage past 60MB/s. (PostgreSQL and Mysql) That's terrible. That's less than USB 2, and even some SD cards can do that! Our on-prem can do 180MB/s on spinning rust and around 550MB/s on (obsolete) SATA SSD. If you want anything better on RDS you have to REALLY pay a premium for IOPs and transfer, or pay a premium for way more ram and a ton of caching, in addition to external caching in the rest of your stack. I have not used Aurora on RDS, so I don't have a comparison, but I have my suspicions. It would be pretty easy to just give you a few more MB/s and make it look a whole lot better. Luckily in our case we could optimize things enough that storage performance didn't matter too much. But RDS storage performance is so pitiful that it's seriously worth considering putting your DB on a bare metal box somewhere with NVME storage and just put up with the network latency and get 50 times the storage performance (and more ram and cpu while you're at it ) at a fraction of the price.
We've gone from 480Mb/sec up to 6Gb, 10Gb, now 20Gb, and we still can't use a native USB cable to network two linux boxes.
Thunderbolt on Mac has this, and there was a very limited solution for linux that was never production ready.
We're still stuck at 1Gb/sec between machines for any networking that isn't cost-prohibitive, impractical, or both.
The cables exist, I look forward to the day when I can plug two machines together and run a network between them over this cable.
Will this ever happen? Or is this a case of hardware vendors blocking open source so that they don't compete with their own jurassic and overpriced 10Gb products?
Going all the way back to USB 2.0, there is a host-to-host mode in the specification, but it's not implemented in any operating system. The best we can get now is USB3.0 to gigabit dongles, which don't take full advantage of the available speed at all.
USB 3.0 is great for storage, the speed is really nice. Then you find that your bottleneck is gigabit ethernet.
Thunderbolt supports network bridging on the mac, but it's not really useable on linux.
What are the roadblocks to IP over full-speed USB 3.0 or 3.1 data link? Is it pushback from the network vendors?
We already have the cheap, fast hardware, but we can't take full advantage of it.
Will there be any effort to use this for networking? It's really about time.
=rmortyh
Two more words: Arbitration Clause. There will be no more class actions.
Wow. It's a shame no one will ever see this.
Yeah, that's crazy. What were they all doing?
They could have just shut down the reactor and had them all pedal!
Look under Settings/Privacy
There is a switch, which reads 'Send Microsoft info about how I write to help us improve typing and writing in the future'
This the collection of keystroke data. They can do anything they want with this. Definitely makes it even more creepy to log in to someplace else on a Windows 10 box.
Another thing which is standard practice is to list all kinds of serious and unlikely reasons they'll use your data, followed by 'or any other legal purpose' which does not mean for some 'legal' matter, which it's meant to sound like, but for ANY purpose which is not SPECIFICALLY ILLEGAL. Which means anything.
You can turn off the keystroke thing, but Microsoft routinely resets preferences, including privacy preferences, when you run an update. So you have to keep checking it and make sure it's off. However, I doubt very much if it matters. You're sending EVERYTHING to Microsoft and they can use it for any purpose.
http://laughingsquid.com/annoy...
Nailed it! 'nuf said...
Hello-
If the 16 port switch is a SMART switch, you can, make the last port a TAGGED port, that carries tagged vlan traffic.
Make each of the other ports (except number one) an UNTAGGED vlan. (keep number one stock so you can access the switch!)
Maybe reserve one for the windows box.
Then, on your computer, run a linux instance with vlans configured, like eth0.2, eth0.3 openwrt would be great for this, you can run it on a little router or a VM.
On the linux box, (openwrt) set up address translation with DNAT and SNAT to make the same IP on each of the VLANS appear as a unique IP on the same network as the windows box. (There's a little voodoo because you don't want any routing to happen, since you have several networks with the same address scheme.) Then, you can run upgrades simultaneously to several different IPs on the windows box (if it lets you) and the physical box it goes to will just depend on which port it's plugged in to.
This VLAN trick is a great way to fake having a whole bunch of network cards in a single box, even a virtual one.
=Rmortyh
I do this sort of thing a lot.
I have found that a 160MB hard drive is probably too old to do the sort of autodetect that most USB-ATA adapters require. These were the days of entering the harddrive parameters in setup...
The best bet for this is to get a PCMCIA network card that has PXE boot capability. Or, a PCMCIA card with a supported Etherboot binary on a floppy disk.
Then boot into a diskless linux setup over the network, and transfer as needed. My oldest net boot image for this is Redhat 9. You might want an even older one, look at Redhat 5 or Slackware 3.3.
This would be most painless because you can just transfer the whole thing over nfs. No messing around with hard drive parameters or matching up new and old hardware. No dealing with windows and dos network drivers beyond just etherboot, which has always worked great for me.
Note that you can do wonders with the old Slackware 3.3 boot disks, boot.i and net.i, maybe pcmcia.i With a PCMCIA network card and the slackware floppies, you may be able to get to an NFS mount in only two or three floppies and no PXE boot. They're also super handy because they'll detect your hardware in that dinosaur and tell you what it is.
If you stay in DOS land you'll have to zip up everything and transfer it with a terminal program, which works but requires lots of space and takes forever.
Also getting networking to work on Windows 3.11 if it wasn't already set up long ago is a big pain and should be avoided.
Best not to mess with the hardware or installed software on it at all. PXE is your friend!!
=Rich
It's a terrible and impractical idea. There is no need for it, other than app makers and data miners trying to make more money, and the police having a new reason to take your phone. It does not improve on the present system which is already computerized.
But more important, will there soon be laws REQUIRING people to carry a phone?
We use custom scripts, that work very well. They're not very complex. We're SMSing through a third-party provider, which is not my first choice, but it is easy to manage.
This is not, of course, extremely secure, but with all the SMS management credentials kept completely separate, it's pretty good.
It gives us the 'something you have' and 'something you know' requirements. You need the phone. In a very well planned and determined attack they could probably get past this, but there are other measures in place, and it makes it hard enough that if they're that determined, they'll try something else.
=rMortyH
You can set up 2nd factor using SMS pretty easily, and have it text you a second password that's good for five minutes.
Definitely the cheapest option.
If you make your own token with an arduino and an LCD and a real time clock and a battery you've already paid for the RSA tokens.
=Rich
'Astrology' means 'the study of stars'. When real scientists began to study stars, this term had already been taken over by crackpots.
So, they adopted 'Astronomy' which is the NAMING of stars, because the more correct term now meant something else.
So, really, astronomy should be called astrology, and astrology should be called bunk.
I thought they owned that word.
Here it is, right on this site, from six years ago.
http://yro.slashdot.org/story/07/10/14/1844209/verizon-wireless-opt-out-plan-for-customer-records
This goes for land line carriers as well.
Did any of these people stop to consider that CPNI data is routinely sold by Verizon and all other carriers unless they specifically opt out?
How many Americans who are complaining about this have opted out of the CPNI sharing clause of their contracts?
You are already giving permission, by not opting out, to your wireless and landline carriers to sell your metadata to ANYONE for ANY REASON, including the government, who may buy it on the open market just like anyone else. This data is seldom anonymized, and when it is, you can still search for specific characteristics to find the information of a specific person. And, any entity willing to pay for the information may have it, and it can be bought through a third-party data aggregator who will de-anonymize it and bundle it with plenty of other interesting facts about YOU.
How many people have actually read their terms of service? Have they gone through the arcane process of opting out of the voluntary sharing of CPNI data? (Every year, for each carrier?) Will they now complain that no one warned them? Did they expect their politicians to keep them informed? If the politicians had tried, would they have listened? They didn't care when this became the norm 10 years ago, and now suddenly it's intrusive?
This is what happens when you don't pay attention.
A killer robot costs way more than a human soldier, and is much harder to replace.
It will be very interesting when this comes into the equation. Are these really to protect the soldiers?
Who will end up protecting whom, and who is more 'expendable'?
Did anyone else notice that it DOESN'T MOVE?
Nice 2:45 video with the usual pornography-inspired music track, but no movement. No 'Robot in action', just a disembodied leg on a treadmill.
Not to knock these guys too much, this is really typical of the robot industry right now. You go to a robot show or conference, and all the 'state of the art' robots are sitting there completely lifeless and no one has "permission from management" to turn them on.
Come on guys, if the industry is going to go anywhere you're going to have to ignore your lawyers and put the batteries in! Otherwise, how do we know you're not bluffing?
Hello-
Most larger APC units have an external battery connector on the back. It uses an Anderson connector to connect an external battery pack. Also, you can chain battery packs, to have more than one. The external battery packs are expensive but they can be worth it for this very problem.
There's also the DIY method for VERY long uptime!
At my shop, in the locked cabinet, we have an ancient APC 1400 unit, with the batteries REMOVED, and two wal-mart deep-cycle marine batteries connected to the external connector. The batteries are 24-DC 12Volt, 75 amp hour batteries in series, for 24 volts. (grey connector) We disabled the beeper in the unit (with pliers... YANK) This keeps a rack with 7 computers up for several HOURS.
This worked so well we decided to go one better! In the main closet, with extension cords running to the machines in the rest of the shop, we have a 3000VA APC unit. It has a 48 volt input (blue connector), not 24. On this sucker we put FOUR 27-DC 115 amp hour deep-cycle batteries, again from Wal-mart (best price, sorry) in series, connected to the back of the unit with the external connector. For these I got lucky and found a really nice set of cables.
This sucker powers all the machines outside the rack, as well as some flat panels, and a desk lamp. (So we don't break our necks!)
I was worried that the current would be too much for the charger, but I've run them down and back up again and they're fine. I guess the UPS units are made to handle two or so external battery packs, so they handle the lead-acid jumbos just fine.
We've had these for a few years, and even had the same power outage here in SF that took out 365 Main a few years ago and had no problems. I need to do another plug-pull test, but our loads are not that high and we can get up to eight hours! Again, pull out the beepers or you'll pull out your hair.
Some tips- You need nice, big cables to do this. Also, there are some code issues for large lead-acid batteries, so if you want to be completely legal buy the APC external battery units. If you buy at Wal-mart find some old dead lead batteries before you go or they'll charge you $9 core per unit. They really don't care if it's the same kind of battery, I traded in the old APC Sealed units for the marine batteries ten times as big! Unlike the sealed ones, the deep-cycles are spillable so be careful. I have never had them spill but if you tip them over they will probably spill some acid.
Have fun!
=Rich
P.S. If you want more info on this or pictures, you can email me (public account) at rich underscore humphrey at yahoo
True, this is false.
There's a picture of a multimeter, and a lighted bulb, but the panel shown is IN THE DARK! Unless it's on a totally different panel that is in the sun, it's way fake. And, as pointed out, 9volts is trivial, but 18 watts is actually really hard.
Also, the reporter is not energy-literate, but that's not a surprise.
I once showed an artist a calculator running on a lemon battery. Not knowing about CURRENT and POWER, she then went and proposed a project to a museum where a classic Gameboy would run on lemons, and they accepted it. Of course this would take a few thousand lemons! Luckily, it was an art museum, not a science museum. We ended up hiding double-A's inside some of the lemons. (We came clean to anyone smart enough to ask!)
I suspect similar shenanigans...
Hello-
I have some experience with this problem. You're right that microcontrollers are too advanced, everyone gets bogged down in the development tools. I also find that most types of IC and transistor circuits where you can't SEE what is happening don't really work out for most kids.
A few kids will get really into it. The next group will 'sort of' get things to work by following the directions, but not understanding what is actually happening. The rest will just sit there while everybody else plays around. They won't even try.
I have found that the basics like lightbulbs, batteries, and switches really get kids excited. They can see what's going on and they understand it and start building on it. Flipping a switch or pressing a button to make something happen is very empowering.
Next, if you can get a hold of some nice relays, especially ones with clear housings, they are really useful for this. It's a switch that turns on another switch. They understand it. (especially with a DPDT knife switch to explain things) Try a reed switch and a magnet, controlling a bulb through a relay. (small switch controls big switch... They learn about current) Let them try the NC contacts. Show them a relay LATCH. Connect the coil through the NC contacts for a relay buzzer. Add a speaker across the coil for a louder buzz. Can you combine these and make a burgler alarm? Show them that a mechanical bell or buzzer is the same as the NC relay buzzer. Next, put a capacitor on the relay coil for a delay. They will UNDERSTAND all this and get into it. And they like the clicking.
This lets them learn by using things they understand like switches and bulbs which are all doing things they can actually see. There are no black boxes at all. Also, a lot of kids want to ignore you and just play. With these parts, they can still make things happen and learn just by messing around. Can they get the relay to click? Make the bulb light up?
I've taught a lot of workshops to beginners and most breadboard type stuff really just confuses them. It seems they have made up their minds in advance that this is something they can't do, it's too hard. With the knife switches, batteries, bulbs and relays, they got really excited. When we added the capacitor they really understood what those did. It seems that this is a necessary first step before you move on to 'black box' parts.
Once you've gotten them there, the next thing is an optoisolator, which is really just a relay. Then they're comfortable with a DIP package, and you can proceed to the 555 and such with the ones you haven't lost. In the meantime, skip all semiconductors completely, except the rectifier diode, which they understand, and maybe the LED (with resistor already soldered on).
As we get better at electronics it becomes more and more difficult to understand what it was like to not know anything about electronics. You try to explain a 555 or op amp and there are a thousand details that you're taking for granted without knowing it. The other person really can't get it without the details, which makes it very hard to teach the subject without losing people. This is why you should go for the basics as much as you can. Let them play in that safe zone and master it and build a foundation before moving on.
Skip Ohm's law and the RC circuits and the math stuff for now. Let 'em turn things on and off. They'll get it.
List: Knife switch, lever switch with roller, button. Reed switch and magnet. Buzzer, bulb, rectifier diode. Clear relays, at least SPDT, DPDT better. Capacitor that can hold the relay on for 1 sec. LED with resistor installed. Speaker with resistor inline (so it can go across the battery without blowing up) . Batteries to match all these (9V or 12V is easiest)
Show them some examples and let 'em go nuts!
THIS IS the Best Phone EVER!
I have two. They're awesome.
4+ years of continuous use,
3 DAYS of battery on ONE HOUR of charge,
NO features except a flashlight,
EXCELLENT sound and reception.
Tons of free chargers and headsets all over
It's just a phone. It just works.
They let me take it into secure places.
I love it.
The only bummer about this story is that now I'll have trouble getting replacements!
Damn.
At least this only works with the European version...
Most interesting, is there are NO BROWN RECLUSE SPIDERS IN CALIFORNIA!
People will argue that there are, and they know someone whose been bitten, but loxosceles reclusa has only been found a handful of times in California in the last 50 years, all of the cases were isolated, and all were traced to shipments from outside the state. (great page from UC Berkeley prof on this that I can't find now...)
A south american recluse has been spotted in the LA area but is not thought to be established.
There are certainly NONE of these in Manteca.
I can tell you though, that although there are none in San Francisco, people will argue that there are to the point of absurdity, so this is a sort of pet subject of mine about how people are wrong.
However, there are so many Black Widows in the Manteca area that you can find several on a twenty minute walk if you're looking for them. Also, Black widow venom IS a neurotoxin, where recluse venom is not. There are also plenty of scorpions and biting centipedes in the area, but no recluses.
Also, in cases where brown recluse IS confirmed, even in one case of large numbers of them in a family home, there were no bites. They're very rare, and necrosis from a CONFIRMED bite is very rare as well.
Most of what you hear about poisonous spiders, even 'first hand accounts', are simply myths. Real brown recluses and black widows are just not very dangerous to healthy adults, and the brown recluses simply does not exist in most places where people claim to have seen them or claim to have been bitten.
I'm most fascinated by the passion with which people will argue against this, even though it can be confirmed just by checking a few books!
=rmortyh