RSSThe $3.00 sprinkler timer
John writes -
A few years ago we built a large cover over our back deck, and shortly thereafter put up a few hanging baskets for flowers. Here (in Arizona) the summers are hot enough that you have to water the baskets at least twice a day to keep the flowers alive. The problem: I forget. Miss watering for one day and there are three hanging baskets of dead and dried flowers. Trust me, I've got three years of dead daiseys under my belt here, and Lisa doesn't let me forget it. Obviously we need an automatic sprinkler system.Hacker's Bench : The $3.00 Sprinkler Timer - Link.
Posted by Phillip Torrone |
Jul 11, 2007 08:02 PM
DIY Projects |
Permalink
| Comments (2)
| Email This |
| Digg this!
Recent Entries
- Best of CRAFT
- Not so lazy Sunday... Weekend Project - Ultimate LED fan sign
- Making Austin Weird: LED Bling
- Brush knuckles
- Found object robot sculptures
- Blob Mentality
- Got 10 hours? Make a paper swan
- Make it or break it
- Maker Faire Austin: Oct. 18th and 19th, 2008, Austin, TX (2 weeks away!)
- Halloween science grossology
Comments
Oldest comments listed first.
| Posted by: saimhe on July 12, 2007 at 7:25 AM |
I always believed that in order to use a LED with AC, a regular diode should be connected in parallel (and backwards, of course) to minimize the reverse voltage. The author does just that in a 24 V circuit, but connects the protection diode serially in a 110 V circuit. Why?
| Posted by: jschuch on July 12, 2007 at 8:15 AM |
Hi Saimhe,
I've always thought the same thing, then I came across this . I didn't quite get it, but I wired it up and my test circuit ran fine for weeks, and nothing got hot. I like this configuration better because it's easier to wire it together and stuff the whole thing in a piece of heat-shrink tubing.
Thanks for the note ... Since you made me go look the original schematic up I noticed that I forgot to note that the resistors are 1W. I've changed the schematic on the page. Thanks!
John
Subscribe to MAKE Magazine!
Subscribe today, save 42% and get web access to MAKE free. MAKE Digital Edition is available only to subscribers.
$34.95 / 1 year
(4 Quarterly Issues)
Features and more @ MAKE!
Add MAKE to iGoogle - GoogleGoogle.
Add MAKE to your RSS reader - Real simple.
Add MAKE on Twitter.
Add MAKE on FriendFeed & the MAKE room.
Why advertise on MAKE?
Read what folks are saying about us!
Click here to advertise on MAKE!
Phillip Torrone
Senior Editor
Tel: 707-827-7311
Gareth Branwyn
Robot Maker
Kip Kay
Video Maker
Jonah Brucker-Cohen
Artist / Researcher
Natalie Zee Drieu
Senior Editor
CRAFT
Becky Stern
Culture jammer
Collin Cunningham
Sound Maker
Marc de Vinck
CNC Maker
Current Podcast
Weekend Project: Ultimate LED Fan Sign
Here is the ultimate sports fan item, a portable Flashing LED Sign.To download Ultimate Fan Sign MP4 click here or subscribe in iTunes....
More...
Leave a comment