Wikipedia:Reference desk/Archives/Computing/2014 April 8

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April 8

Name that electric switch

I want some rather bright lights to go on when I open the garage door. The garage door opener has it's own provision to do that, but is limited to 60 watts. I want 200 watts. So, when the line coming from the garage door opener is energized, I'd like that to flip a switch to turn on my lights using mains power, and then turn it back off when the garage door opener line goes dark (it has a timer). What's the name of the switching device to do this ? StuRat (talk) 03:51, 8 April 2014 (UTC)

Any commercial product that did what you wanted would be called a switch, but it would actually be some sort of Relay.

https://en.wiki.x.io/wiki/Relay

One that is either triggered by AC electricity and you plug it into power AND the light socket of the garage door opener with a socket to outlet converter as the switch.

https://www.google.com/#q=socket+to+outlet+adapter

Or, a relay that is switched by light. But you would have to make sure the additional lights you added would not trigger the light sensor to your switch. It could make for unusual positioning.

I've looked and I'm not seeing any kind of product. However, the 60 watt limit on garage door opener is due to the heat that would discolor or melt the white garage light cover. You could plug in a socket to outlet converter (mentioned earlier) and run an extension cord to more powerful light. However, I would use LED bulbs and maybe not go quite as bright as 200 watts. With LED bulbs you are getting the additional brightness while drawing considerably less electricity and not generating as much heat through the garage door wires just to play it safe.Wonderley (talk) 05:33, 8 April 2014 (UTC)

I'm using 15 CFL bulbs at 13 watts each, for a total of 195 watts, to light up the entire exterior of the house, for security reasons. StuRat (talk) 06:18, 8 April 2014 (UTC)

I did that too. I used a motion detector. As the relay. A car coming up the driveway signals it. I wired all that up 20+ years ago. I think I got the motion "switch" at Home Depot.Wonderley (talk) 16:09, 8 April 2014 (UTC)

I recommend wiring up a mechanical relay that is closed by the power for the opener light. Katie R (talk) 17:37, 8 April 2014 (UTC)

And now I see Wonderly mentioned that - skimming the response I thought it was just suggesting a light-triggered relay. You might also be able to find some useful signals on a terminal block on the opener. When I installed mine, I'm pretty sure there was a screw terminal with a TTL-level signal indicating the status of the light. That would give you a cleaner looking installation, and you could still have a bulb in the opener. Katie R (talk) 17:43, 8 April 2014 (UTC)

I have a fancy power board called a master slave, i wonder if you could use something like that? For example you plug your PC into the master and everything else (monitors, speakers, external peripherals etc...) into the slave sockets. The board monitors the current in the master socket and only turns on the slaves when the master is drawing then a few hundred mA. So if you plugged in your roller door into master and all your other lights into slave, that might work, depending on the layout of the socket etc... Vespine (talk) 06:16, 9 April 2014 (UTC)

How much does that cost ? StuRat (talk) 08:26, 9 April 2014 (UTC)

Great idea Vespine! That's the perfect relay. Hmm,...if it works. I have one of these for my PC.

http://www.walmart.com/ip/Inland-NuGiant-Energy-Saving-Smart-Surge-Protector/14664815

When power from my PC is off (The PC is plugged into the surge protector's outlet that works as a switch), it kills all power to the other outlets on the surge protector (Monitor, printer, speakers and could do more). These are the other surge protector's "Energy saver" outlets. Plug this product (Or similar) into the power outlet normally used for the garage door opener. Plug the garage door opener into the one AC outlet on the surge protector outlet for a PC or TV (The switch). Plug your lights into the "energy saver" (Switched) outlets.

A PC uses power even when it is off, but the surge protector knows it's just a little. I suspect the little bit of electricity used to operate just the remote receiver is little enough to be recognized as "off". But just the additional lights has to be recognized as "on". I'm sure the motor will be seen as "on" as far as the surge protector is concerned, but it runs for a very short time. If the lights in the garage door opener do not draw enough power to make the surge protector think it is "on", it will only make the lights plugged into this surge protector only work while the door is in the process of opening and the motor running.Wonderley (talk) 10:40, 9 April 2014 (UTC)

That says it will "detect when you have turned your electronic device off and will shut off power to that outlet" (presumably to cut power to things like wall warts, when not in use), but I need it to shut off power to the other outlets, not that one. StuRat (talk) 17:47, 9 April 2014 (UTC)

UPDATE: The manufacturer site says it works as you described: http://inlandproduct.com/energysavingsmartsurgeidealforhometheater.aspx. Walmart apparently got it wrong in their description. StuRat (talk) 18:19, 9 April 2014 (UTC)

UPDATE 2: I ordered it ! Let's hope it gets the job done. Thanks all. StuRat (talk) 02:54, 10 April 2014 (UTC)

I agree - that does sound like a great, simple solution. Very clever! StuRat, I am curious about how your exterior lights are wired. If they're already set up to plug into an outlet, then that solution is perfect. I guess I pictured the power coming into a junction box with a light switch to control them, in which case putting a relay in the box in place of or in parallel with the switch would still be cleaner. If you're lucky and the opener manual says there is a 5V light signal, then you wouldn't even have to run line current from the opener to the relay, just a tiny pair of 5V wire. I think there are Kendal Electric locations on your side of the state - they could help you pick the right relay for the task and find one that is up to code mounted in a junction box. They aim to sell to contractors and electricians, but are happy to help out anyone. Katie R (talk) 17:35, 9 April 2014 (UTC)

My "exterior lights" are actually 3 inside floor lamps pointed towards windows, with five 13 watt CFL bulbs each, providing the equivalent of 60 watts of incandescent light per CFL, for an actual wattage of 195 and equivalent of 900 watts (65 actual watts and 300 equivalent per lamp). The old system used a motion detector and a 300 watt halogen light mounted on the exterior, some 20 feet up, requiring a dangerous trip up a ladder to change the bulb (always in January, due to Murphy's Law), and the motion detector never worked well, and has now failed entirely. Unlike the old system, everything plugs into an electric outlet now, so no wiring is required beyond running extension cords. And I can change a bulb now without needing to do anything beyond unscrewing the old one. StuRat (talk) 17:55, 9 April 2014 (UTC)

Thanks all. As I noted previously, I've ordered the device to fix this problem. StuRat (talk) 16:00, 10 April 2014 (UTC)

Resolved

protecting a folder

How can I protect a folder in Windows 7? Thank you.175.157.16.134 (talk) 10:06, 8 April 2014 (UTC)

Protect it from what ? Being read by others ? Modified by others ? Copied by others ? Deleted by others ? Being read/modified/copied/deleted by viruses ? Accidental modification or deletion by you ? Hard disk failure ? StuRat (talk) 13:03, 8 April 2014 (UTC)

Your question is unclear, but if you right-click on the folder name (in Windows Explorer), then click "Properties" you will be offered various security options.--Shantavira|^{feed me} 14:39, 8 April 2014 (UTC)

You can protect your folder from external threats by downloading the free application . The application is open-source i.e., you can see what you are doing BUT with certain limitations. You can download it here . The size of the file is just 200 KB. or You can search Stegnography in wikipedia — Preceding unsigned comment added by Shrimadhav (talk • contribs) 08:59, 9 April 2014 (UTC)

I strongly recommend against using that program ("SpEcHiDe"), whatever it's supposed to do. It is very likely to be snake oil or even malware. -- BenRG (talk) 23:44, 9 April 2014 (UTC)

I believe TrueCrypt is well thought of, though I have never used it. All the best, Rich Farmbrough, 17:44, 10 April 2014 (UTC).

There is no malware in SpEcHiDe. You can check he source code of it which s available on request. It works on a small bug in Microsoft Windows which has not yet been patched.

More intense disk activity

Some time ago I found this useful utility - http://download.sysinternals.com/Files/ProcessMonitor.zip - and got my machines behaving quite nicely. Now there is a lot of disk activity, which happens mainly while the screens are in power-down mode. There also seems to be a lot less free disk space than I thought. Is this some new un-feature from a Microsoft upgrade? Or is it a known security issue I should worry about? I am fairly security concious, but of course visitors jump on and off the LAN these days, so my security model is a little outdated. All the best, Rich Farmbrough, 11:26, 8 April 2014 (UTC).

Depending on your operating system, it might be the indexer for Windows Search--Phil Holmes (talk) 14:27, 8 April 2014 (UTC)

Thanks, I did mean to say that indexing is turned off. Who knows though with Windows... (Vista)> All the best, Rich Farmbrough, 15:16, 8 April 2014 (UTC).

I have a 15" CRT monitor and intend to buy a 1GB GPU which would give 1900X1200 resolution but would my monitor support it?

I don't care how tiny things would look!!! I don't care how tiny things would look!!! I don't care how tiny things would look!!! I just want to play games in better graphics however i can lower down the screen resolution while playing the game. . . . currently i have 1024X968 resolution on a NVIDIA 6150SEn430 GPU and i want a better GPU and i've played Bioshock, Halo 2 and few others games on it but in low graphics mode :(( I have processor: AMD Athlon Dual core 64X2 5400+ (additional info) and 3Gigs of RAM.(additional info) . . LG500G is the model of the monitor — Preceding unsigned comment added by Shikka Kun (talk • contribs) 13:38, 8 April 2014 (UTC)

Every monitor has a maximum resolution that it will support, and there is no way to go beyond that. For yours the maximum resolution is 1024x768. If you want better resolution, you'll have to buy a better monitor. Looie496 (talk) 14:03, 8 April 2014 (UTC)

And that likely means a larger monitor. Alternatively, you could use bump scrolling, if that graphics card supports it, to view a portion of the scene at once, giving you a larger effective resolution, although you only see 1024x768 of it at a time. If you are on Windows 7, 64 bit, you can use Microsoft's own magnification feature to do this. At a 200% zoom level, for example, you'd get a total resolution of 2048x1538, but would only see 1/4th of the screen area at once. StuRat (talk) 14:08, 8 April 2014 (UTC)

BTW, if the expense is the reason not to get a new monitor, you can get a used CRT monitor for free or almost free, as everyone wants a flat screen now. StuRat (talk) 14:24, 8 April 2014 (UTC)

And there are surprising bargains on older LCD's, even 1080i LCD TV's which support the resolution you need. We heard what you said (3 times) but really, the electricity you would spend on running a CRT (assuming you get a cheap LCD) would soon exceed what you are trying to save. Sandman1142 (talk) 22:14, 8 April 2014 (UTC)

Freeview Manual Tuning - Missing Channels

I was looking at the wiki page for the Freeview channels for the UK & I noticed that there where a few channels listed on that page which aren't listed on my TV's channel list. I auto retuned & when I've looked again at the TV's channel list The missing channels aren't there. Does anyone have a list for the UHF Channels for the TV channels on Freeview so I can do a Manual Retune ? 194.74.238.6 (talk) 14:11, 8 April 2014 (UTC)

If it's like in the US, we had lots of digital TV channels that came and went in short order, so the channels may really be gone now. StuRat (talk) 14:19, 8 April 2014 (UTC)

Manual tuning is unlikely to help. A whole multiplex is transmitted in one radio channel, so you'd expect to get all the channels in the multiplex or none. And if the autotune didn't see a strong enough signal, the channel will be too weak to watch (digital signals don't degrade as gracefully as their analog forebears). What's in which multiplex is listed at Digital terrestrial television in the United Kingdom#Multiplexing. The frequency a multiplex is broadcast varies by transmission tower - so you need to figure out which tower your antenna is pointed at. See {{Television transmitters in the UK}} and sites like http://www.thebigtower.com But if you're not getting all the multiplexes your tower transmits (check: some towers or relays don't carry all yet) you might need a better antenna. In a few cases people with older Freeview equipment needed to change the firmware in their digibox or tv to handle changes; that should have happened automatically, but you might want to see if you can force that. -- Finlay McWalterᚠTalk 14:27, 8 April 2014 (UTC)

Oh, right. Well for example, on the Freeview (channel list) page CBS Reality & on the page for CBS Reality, it on Freeview channel 66. If I had/got the UHF Channel for CBS Reality I could try & retune my TV to see if I can find it. 194.74.238.6 (talk) 14:32, 8 April 2014 (UTC)

I've checked & I think I'm under the Winter Hill transmitter. 194.74.238.6 (talk) 14:34, 8 April 2014 (UTC)

I know that, for example, BBC channels (I think all of them) are UHF Channel 50 (at least for me). So like I say if I could get a list for for all the TV & radio channels & what UHF channel they're on I could try & retune manually.194.74.238.6 (talk) 14:38, 8 April 2014 (UTC)

The channels, and frequencies, for Winter Hill are listed at Winter Hill transmitting station#Digital. -- Finlay McWalterᚠTalk 14:55, 8 April 2014 (UTC)

Thanks, I'll go & see if they can help. 194.74.238.6 (talk) 15:07, 8 April 2014 (UTC)

I just retuned my TV (I'm on a different transmitter, so different UHF frequencies to you) and I do indeed now get CBS Reality at #66 on the EPG. As the articles you linked indicate, it is on the COM4/SDN multiplex (same as ITV3+1 and ITV4+1 and other garbage channels). Winter Hill transmits that multiplex on UHF58. I would expect that if you have antenna problems you wouldn't see anything in that multiplex. -- Finlay McWalterᚠTalk 15:17, 8 April 2014 (UTC)

Well, I've tried manual retuning & stil don't have all the missing channels. So I'll think I'll leave it for a while, thanks for the help anyway.194.74.238.6 (talk) 12:10, 10 April 2014 (UTC)

openning tex file in swp 5.5

Scientific work place 5.5 is installed on windows xp in my computer .My supervisor has sent me a thesis files through mail, which contain a tex file abc.tex and other files as title.tex ,abstract ,preabble1.tex and bibliography.tex ,when i try to compile abc.tex message appear ,"valid .cst file not found ,document may not load correctly.would you want to continue ." when i continue this then it opens,then when i try to compile and create pdf file, no pdf file is created,in ttue tex DVI previewer it says ,preamble1.tex not found .I have searched it on internet ,i have found that problem is with tex style file.Then I imported all files in new folder then try,then while compiling no pdf is created ,because it can not find title.tex,abstract.tex ,..... . Style of this thesis is similar to harvard. — Preceding unsigned comment added by True path finder (talk • contribs) 14:30, 8 April 2014 (UTC)

Somewhat ironically given your user name, it seems that the problem is that the LaTeX processor does not have its search path set up correctly. The main file abc.tex probably consists largely of lines saying \include{foo} for various values of foo, but when the processor looks for the file foo.tex, it doesn't find it. Unfortunately I don't know enough about your setup to go beyond that. Looie496 (talk) 15:03, 8 April 2014 (UTC)

Text messages on Nokia Lumia

I recently needed to send a text message to a recipient on my mobile phone. The phone I have is a Nokia Lumia 820 my company gave me to use. I didn't have the recipient's number already in the contacts list on the phone, so I tried to just send the message to the actual number, like it had been possible on all previous Nokia mobile phones for the past two decades. Disappointingly, I didn't find any way to do this. The text messages application only allows selecting recipients from the contacts list, and the only actual numerical telephone keyboard I could find on the entire phone (in the telephone application) only allowed me to actually call the number, or store it as a contact. Is there any way to actually send a text message to an actual number on Windows Phones? It has been possible on previous, non-Windows, Nokia phones for over two decades, and I am sure most of these new-fangled touch-screen phones from other vendors (not running Windows) allow it too, although I'm not sure, since I've never used them. Has no one in either Nokia or Microsoft ever thought of this? JIP | Talk 18:46, 8 April 2014 (UTC)

According to the user manual (link) within the 'create new message' area you simply type the number in (suggestion being it's the same field you would add a recipient to). Relevant page of the manual I've linked to is page 47. Sorry it's not a phone/system come across but I am 99% certain it will be easy, it's just modern phones have made a good job of making easy tasks more difficult by their desire to be minimalist in on-screen design. ny156uk (talk) 19:40, 8 April 2014 (UTC)

If that works, it's the same for Android phones at least with the default non Hangouts SMS app. In Android, if you're desperate for a numeric telephone keyboard for some reason, you can I guess temporarily switch your keyboard to one although it seems easy enough to just use the QWERTY keyboard if it's only one or two recepients. I've never had that much of a problem entering a phone number using the QWERTY keyboard personally, even on my old LG P500 with its small screen although I guess it may be a bit easier if you have a large number of recepients you want to enter by phone number. Alternatively with Android you could I guess download an alternative SMS app which would provide an option for a numeric keyboard when entering the recepient. Perhaps there are other options, I'm not sure since as I mentioned I've never felt the keyboard to be a big problem. And I can't say which, if any, of these will port over to Windows. Nil Einne (talk) 06:41, 9 April 2014 (UTC)