HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  INDUSTRIES  |  FOCUS ON FUNDAMENTALS
REGISTER   |   LOGIN   |   HELP
Page 1/3  >  >>
BG
User Rank
Iron
Re: KISS - keep it simple *******
BG   7/31/2013 3:43:49 PM
NO RATINGS
Hi Tom,

Love all the differnet takes on this.  Got one more; a person could hang the lights just under the path of the door so you could always be able to use the light, no?  :)

Might have to cover them instead of letting the bulbs be exposed and that low though.


Take care!

 

mrdon
User Rank
Gold
Re: Household solution
mrdon   6/18/2013 6:46:10 PM
NO RATINGS
Cadman-LT

Thanks. That's one of the joys of teaching: watching students succeed.

Cadman-LT
User Rank
Platinum
Re: Household solution
Cadman-LT   6/17/2013 6:32:40 AM
NO RATINGS
mrdon, I understand what have to do. I also like the challenges. It probably proves who really wants to succeed. Books are one thing, but getting a challenge that isn't in any book....I like that and apparently so do the students. Good work.

TomM
User Rank
Iron
Re: KISS - keep it simple *******
TomM   5/26/2013 10:04:17 PM
NO RATINGS
Simple is in the eyes of the executioner . . .

I happen to have a stash of the solid state relays with the front end circuit board already installed. Adding the doorbell transformer allowed me to use a low voltage reed switch on the door frame, which minimized any shock hazzard.

A really simple solution would have been to add another light switch, but would not have nearly as much fun :-)

Regards,

tom

mrdon
User Rank
Gold
Re: Household solution
mrdon   5/22/2013 2:31:56 PM
NO RATINGS
Cadman-LT,

The ITT-Tech Curriculum is very rigid and compact with several classroom assignments for the students to complete within 10weeks. Before this new teaching direction, I presented such challenges as you suggested with only a small percentage of them wanting to work on the project. The students who did meet the challenge thought it was the greatest learning experience and wish more instructors provided design challenges as well. 

The online courses I'm developing at Udemy will allow me to add design challenges in my syllabus. Here's a RPi course I developed for them which is going through beta testing right now. 

https://www.udemy.com/raspberrypi/?instructorPreviewMode=guest

Cadman-LT
User Rank
Platinum
Saving energy
Cadman-LT   5/17/2013 10:06:44 PM
NO RATINGS
I guess any way to save a little energy is always a good thing.

Cadman-LT
User Rank
Platinum
Re: Household solution
Cadman-LT   5/17/2013 10:03:44 PM
NO RATINGS
mrdon, I was curious. Do you ever give your students a complicated design and ask them to simplify it? That might be a good exercise for them.

Charles Linquist
User Rank
Silver
Similar project
Charles Linquist   5/15/2013 10:21:32 AM
NO RATINGS
I have a Chamberlain "Lift Master" garage door opener.  It has two sockets for lights.  Each of the sockets is labeled "65W MAX".  Since I like to save energy whenever I can, I removed the incandescents and put in CF bulbs.  I never thought that the 25W (or so) that the CF bulbs consumed would be a problem, but after a year or so, the lights stopped working when I opened/closed the garage door.  I traced the problem to a small OMRON relay on the control PCB.  Apparently, the CFs present a load that is not 'friendly" to small relay contacts.  I looked for a replacement relay on Digi-Key, but soon realized that this was a custom part.  I also found out that when I removed the relay, the garage door opener quit working.  Apparently, the relay coil was part of the circuit, so I soldered the (defective) relay back in place.

 

At first, I was just going to buy a new control PCB and be done with it, but instead  I realized that I  could build something myself to fix the lights and also  solve a problem that plagued me - I would sometimes leave the garage door open overnight. 

I got out a small Microchip development board (18F2221) and a solid state relay that I had lying around.  I needed a power supply, so I found an old cell phone charger, cut off the "prongs"and soldered wires to the stubs that remained.  I used liberal amounts of GOOP from the hardware store to cover and insulate the connections. All of this fit into a standard square metal outlet box.  While I was at Home Depot, I found an outdoor light fixture that held two spot-lights and screwed directly to the top of the outlet box.  I connected the solid state relay to the lights and mounted two "barrel type" connectors (the round types that are used everywhere for power).  I chose two different sizes so that they couldn't be plugged into the wrong connector.  I wired one to a magnetic reed switch that could sense the position of the garage door and the other to the garage door "close/open" switch.  I also added a small 5V relay to the Microchip development board and used the contacts to handle the garage door signal. I used screws and standoffs to mount the things that had holes and GOOP to mount the things that didn't (like the cell phone charger).

Now, when the reed switch opens (indicating that the garage door has been opened), the lights come on for a programmed amount of time, and when the door closes, the lights stay on for a different programmed time.  If the door has been open for 29 minutes,  the lights flash.  After one more minute, the lights flash again (as a warning)  and the door automatically closes. 

Later, I added a pushbutton switch that has several functions: pressing and holding for 2-5 seconds turns the lights ON permanently.  Pressing and holding it for 2-5 seconds again turns them OFF . Pressing and holding for 10 seconds delays the automatic closing for 8 hours (for the times I'm working in the garage).  I use the lights as indicators (a flash pattern indicates the state). Opening or closing the garage door in the "normal" way resets the system.

Of course, if something is blocking the garage door, the normal Chamberlain optical sensor prevents it from closing, so the system is safe.

Everything has been working perfectly for over two years now. 

ian_m
User Rank
Iron
KISS - keep it simple *******
ian_m   5/15/2013 6:08:22 AM
NO RATINGS
Why not just use a normally closed reed switch and magnet ?

 

No messing with components, soldering etc, just becomes a simple wiring job.

 

My company once supplied 19inch cabinets with built in fluorescent lights that came on when the cabinet door was opened. This was done with a normally closed (actually a change over type) 3A 250V proximity switch so lights were on when the cabinet door was open. When the magnet on the door closer got close to the switch, when the door was closed, it opened the contacts and turned the internal light off.

All a nice and simple internal wiring job.

ian_m
User Rank
Iron
KISS - keep it simple *******
ian_m   5/15/2013 6:08:21 AM
NO RATINGS
Why not just use a normally closed reed switch and magnet ?

 

No messing with components, soldering etc, just becomes a simple wiring job.

 

My company once supplied 19inch cabinets with built in fluorescent lights that came on when the cabinet door was opened. This was done with a normally closed (actually a change over type) 3A 250V proximity switch so lights were on when the cabinet door was open. When the magnet on the door closer got close to the switch, when the door was closed, it opened the contacts and turned the internal light off.

All a nice and simple internal wiring job.

Page 1/3  >  >>


Partner Zone
Latest Analysis
Samsung's 5th-generation Android-based Galaxy smartphone includes a fingerprint scanner, updated camera and display, and water/dust resistance.
Worldwide economic expansion is spurring growth in industrial machinery sales to 5% or 6% per year through 2018.
Last year at Hannover Fair, lots of people were talking about Industry 4.0. This is a concept that seems to have a different name in every region. I’ve been referring to it as the Industrial Internet of Things (IIoT), not to be confused with the plain old Internet of Things (IoT). Others refer to it as the Connected Industry, the smart factory concept, M2M, data extraction, and so on.
Vitaly Svetovoy, of the University of Twente in The Netherlands, and his team, has created the world’s smallest internal combustion microengine.
Some of the biggest self-assembled building blocks and structures made from engineered DNA have been developed by researchers at Harvard's Wyss Institute. The largest, a hexagonal prism, is one-tenth the size of an average bacterium.
More:Blogs|News
Design News Webinar Series
3/27/2014 11:00 a.m. California / 2:00 p.m. New York / 7:00 p.m. London
2/27/2014 11:00 a.m. California / 2:00 p.m. New York / 7:00 p.m. London
12/18/2013 Available On Demand
11/20/2013 Available On Demand
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Apr 21 - 25, Creating & Testing Your First RTOS Application Using MQX
SEMESTERS: 1  |  2  |  3  |  4  |  5


Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
Next Class: April 29 - Day 1
Sponsored by maxon precision motors
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
Copyright © 2014 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service