 Battery Powered Desk Back Light LCD Digital Alarm Clock US $13.22 
|
 Desk LED Night Light Pink Numeral Quartz Alarm Clock US $12.29
|
 Color Changing LED Light Alarm Clock Mood Desk Top Lamp US $10.95
|
I want to make a door alarm that turns on an indicator light instead of a siren. How should I start?
Firstly, I am pretty good with electronics. The issue: I've found that while having my desk face away from the entry door into my home office while either listening to music or using headphones I often am unintentionally startled by people coming into the room behind me. So I would like to make a device that lights up a small LED on my desk when the door is opened so I could prevent my inevitable heart failure.... I'm just not sure where to start on this one... or maybe something like this already exists and I an just unable to find it?
Go buy magnetic door/window switch, likely an NC type. Run wires from it to a battery and indicator, so the door opening will turn it on. You could get a bit elaborate with a blinker and a time-out timer with a microcontroller or NE556 (dual 555) timer chip.
You could also just get a mirror.
Whats On My YouTube Today?
LOCOMO - White LED Keyboard Lamp Table Desk Light
Here Are A Few Items From Amazon You Might Be Interested In.
| Account limit of 2212 requests per hour exceeded. |
Items recently purchased on this site:
Green Plastic Stand Mini Round Desk LED Mirror Alarm Clock, Digital Big Jumbo LED snooze wall alarm calendar countdown large gadget clock, Thermometer Timer Alarm Blue LED Light Music Desk Clock, Modern Desk clock White Wood Alarm Wooden Digital White LED, Modern Desk Clock Black Wood Alarm Wooden Digital White LED, GLOWING LED light mood night color changing digital Alarm desk clock Thermometer, Digital LED Blue Backlight Snooze Alarm date desk Clock white LCD screen display, Digital Large Big Jumbo LED snooze wall desk alarm with world time travel clock, New LCD Digital Music Desk thermometer Calendar LED Blue backlight Alarm Clock, Digital Large Big Jumbo LED snooze wall desk alarm with calendar indoor clock, B09 HELLO KITTY 7 LED COLOR DIGITAL TABLE DESK ALARM CLOCK, Digital Large Big Jumbo LED snooze wall desk alarm thermometer funny color clock, Digital Large Big Jumbo LED snooze wall desk alarm with calendar light clock, Digital Big Jumbo LED snooze wall desk alarm count down novelty clock, Office Clock 4" LED Alarm with Remote Control, Desk Digital LCD Weather Station Tempature Clock Alarm Time Projection, Orange Red Battery Powered Mini Desk LED Mirror Alarm Clock, New Led Zeppelin Travel Desk Top Alarm Clock Night Light, Light Blue Plastic Stand Mini Desk LED Mirror Clock, LCD Large Simple Display Blue Cube Snooze LED Digital Desk Alarm Clock White, Mini Cute Egg-shaped LCD Screen Digital display Wobble Table Desk Alarm Clock , Desktop Digital LCD Weather Station Tempature Snooze Clock Alarm Projection, radio shack 63-1411 desk led alarm clock date time temperature, Digital Large Big Jumbo LED snooze wall desk alarm count down world time clock, 7 LED Color Change Digital Desk Alarm Clock + Thermometer Calendar, NEW White Digital LCD Alarm clock calendar Temperature Backlight Time Countdown , White LCD Display Thermometer Blue LED Music Desk Clock, LCD Large Simple Display Blue Cube Snooze LED Digital Desk Alarm Clock Black, 7 Led Color Change Digital Desk Alarm Clock + Thermometer Calendar, Bedroom Desk Plastic Quartz Alarm Clock White Tea Green, Digital Large Big Jumbo LED snooze wall desk alarm calendar count down clock, JUMBO 4" LED Alarm with Remote Control, Digital Large Big Jumbo LED snooze wall desk alarm calendar world time clock, Blue Arabic Number Dial Bedroom Quartz Desk Alarm Clock, Electronic Desk LED Light Clock Digital Display Calendar Temperature all in 1, Digital Large Big Jumbo LED snooze wall desk alarm with calendar travel clock, Baby Blue Plastic Battery Powered Home Desk Alarm Clock, Colourful Digital Projector Ray LED Alarm Clock Desk clock Time Projection, Tea Green White Plastic Numeral Desk Quartz Alarm Clock, Digital Big Jumbo White LED Snooze Wall Desk Alarm Clock 3x1 in' 613a, Digital LCD LED Snooze Alarm Clock Desk Cube, Digital Big Jumbo LED snooze wall desk alarm with count down indoor clock, Sony ICF-C318 Clock Radio with Dual Alarm (Black)-NEW, Colorful LED Flashing Light Photo Album Digital Alarm Clock, Round Dial LED Light House Shaped Baby Blue Alarm Clock, Glitter Arabic Numbers LED Night Light Desk Alarm Clock, Table Desk Black Silver Tone Numeral Quartz Alarm Clock, White Maroon Plastic Quartz Bedroom Desk Alarm Clock, DIGITAL WEATHER STATION PROJECTION ALARM CLOCK MULTI-FUNCTION COLOR DISPLAY USA, Big Digits Digital Jumbo LED Snooze Wall Desk Alarm Clock 3x1in. Four Colors 613, Digital LED Wall Desk Alarm Clock W Calendar Temperature Metal Frame 614, Battery Powered LED Night Light Quartz Desk Alarm Clock, Battery Powered Desk Back Light LCD Digital Alarm Clock, Desk LED Night Light Pink Numeral Quartz Alarm Clock, Color Changing LED Light Alarm Clock Mood Desk Top Lamp,
Thanks for visiting!
Tags: alarm_clock, dealextreme, led desk alarm clock, desk_clock, digital_alarm_clock, clock