What kind of led is used in...

Forum 2005-2010 (read only) General Frequently-Asked Questions
1

My daughter came home with a 'spy gear' item from a fastfood restaurant. When you switch it on, it starts beeping when people walk in front of it. Even when they are about 6 feet/2 meter (or a little more) away.

The sensor seems to be some kind of led.

Can anyone tell me what kind of led this is?

The item is the same as in this ebay auction: http://cgi.ebay.com/2006-McDonalds-Spy-Gear-Happy-Meal-4-VHTF_W0QQitemZ190256855782QQcmdZViewItemQQptZFast_Food_Cereal_Premiums?_trksid=p3286.m20.l1116

Thanks in advance!

2

i would wager that its an infrared emitter/detector pair, like this

3

You could be right about the detector, but there is only 1 led for detecting. The other led is red (blinking most of the time) led.