November 22, 2008
By now you have probably seen the outdoor christmas lights that are solar powered (offer you a savings on your power bill)
Lets find out how long it takes for the lights to pay for themselves.
I have some 3 year old LED lights that i use for decorating the house.
Using a Kill-a-watt meter the 150 light strand uses 4 watts of power.
This is which is 27milliWatts per light.
A new standard 100 LED light strand is $17 from canadiantire.
A solar powered strand of 50 LED lights is $25 from canadiantire, so 100 lights would cost ($25 * 2)=$50. These solar powered lights will stay on for up to 6 hours per day.
The cost difference is ($50-$17)=$33. So we need to save $33 off our power bill to break even.
Now lets calculate how many hours we need to operate the regular strand to reach the break even point.
I pay $0.07 per kwh from the power company.
27mW * 100 = 2700mW = 0.0027kW = killowatts used per strand.
$33 = ($0.07/kwh)*(0.0027kw * hours)
($33/$0.07kwh) = (0.0027kw * hours)
471kwh = (0.0027kw * hours)
471kwh/0.0027kw = hours
174603h = hours
So to be cost effective we need to use the solar lights for more than 174,603 hours which is 7275 days (or 20 years) of constant use. But lets not forget that the solar powered lights only operate for 6 hours per day.
174603h/6hours per day = 29,100 days at 6 hours per day
29100/365 = 80 years at 6 hours per day, (everyday of the year).
Now if you used your christmas lights for 3 months a year (any more than that is just silly) you get:
80/0.25 = 320 years (at 3 months a year (for 6 hours a day)).
To summarize, you would need to use a strand of lights for 320 christmas seasons for it to become cost effective to buy a solar powered strand of lights.
But wait, there’s more.
A typical LED has a life of 50,000 hours, but by the math above we would require 174,603 hours to reach the break even point. So it is not even remotely likely that the LEDs would last the time required to get to the 320 seasons to break even (… i am not even going to get into the life of the solar panel).
So save your money… dont buy solar powered christmas lights.
Posted by mb under Tips | Comments (3)
June 6, 2007
I am a big fan of keyboard shortcuts. The 3 shortcuts I use the most are not known to most people, they are cut, copy and paste. Now this is not the standard CTRL-X, C, & V but better (IMHO). Here they are:
copy : CTRL-INSERT
paste: SHIFT-INSERT
cut : SHIFT-DELETE
These shortcuts work in almost every application I have come across (except a few Java applications), AND it works on both windows and Linux. Also if you switch between a qwerty and dvorak keyboard layout, the keys for the shortcuts don’t change with your layout (like C, V and X do.)
Posted by mb under Applications, Tips | Comments (0)
May 22, 2007
2009.01.10 - edit - The links to the pictures are now broken, i migrated servers and did not bring the old gallery to the new host.
If you know me, then you know a few things about me; I use a Dvorak keyboard layout and I am rarely satisfied with the norm. Now if you know anything about Dvorak, the keyboard is laid out much more ergonomically, all the vowels are under your left hand on home row, and under the right is the most used consonant. The major reason I switched to Dvorak was my wrists; using Qwerty my wrists hurt almost constantly. It took about a month to switch, and now that I have my wrists don’t hurt.
So at this point I am assuming that I have you convinced. Now you want to know, where can I get an inexpensive Dvorak keyboard… well there in lies the problem. They are not cheap, and anything you could find for a reasonable price is so ugly you wouldn’t want to touch it.
For the past few years I have been using an IBM keyboard from the mid-eighties. This keyboard kicks butt. By default it is a QWERTY keyboard, but all the keys are interchangeable so switching it to a Dvorak layout is trivial. The keys have excellent tactile feedback, and a great mechanical ‘Click’ sound for every keystroke you make. But i find myself missing my old school Microsoft Natural keyboard (There was an incident, water was involved, keyboards were hurt).
Recently Microsoft released a new version of the Natural Keyboard, with a better design than ones of late; mainly the insert / delete / home … keys are back to their standard layout. The keyboard is the Microsoft Natural Ergonomic 4000. It features a whack of media keys and a “Zoom” slider that can be hacked for more useful purposes. The major problem is of course that it is not offered in dvorak, so we need to fix that.
Step 1.
Get a Microsoft Natural Ergonomic 4000. If it doesn’t come in a brown or white box you are paying too much. I got mine from MemoryExpress for $50 CAD, and it came with a fancy tilt wheel mouse.
Step 2.
Remove the letters that we need to re-label
Step 3.
Sand off the original lettering. Yes, you are going to paint them anyway, but if you don’t the flat spot where the letters are printed will be visible when you are done.
Step 4.
Paint. I recommend Krylon Fusion because it bonds to the the plastic. and a satin finish to better match the rest of the keyboard. If you have some magic way of making a laser printer print white toner on a clear label then I definitely recommend the satin black. Since my color laser printer prints everything but white I had to choose a paint color that would allow the black letters (on the clear label) to be seen. So silver it is.
Step 5.
Print the letters on clear labels, and place them on the FRONT of the keys. If you place the letters on the top of the keys, I suspect it wont be long before they come off and leave a sticky mess.
Download my letters template (letters.doc). Even though its a ms-word doc, I suggest using OOo.
Step 6.
Re-assemble the labeled letters on to the keyboard.
Step 7.
Enjoy.
Also available in un-lettered black.
I have used this keyboard at work for about a month now. The paint looks as good as the day I sprayed it, but I do miss the feel and sound of the old IBM keyboard. (although I’m sure my co-workers don’t miss it.)
Here is the mod gallery.
Posted by mb under Hacks, Mods, Tips | Comments (2)
December 20, 2006
I got tired of always copying text off web pages and pasting it into Google, I also got tired of copying and pasting non-hyperlinked URLs on websites… The solution is a bookmarklet that i created, I call it:
Goto Selection
The linked page explains more and gives examples… check it out.
Posted by mb under Tips, Web | Comments (0)
