Buzzer:

What is it?

A buzzer is a device that makes a buzzing noise when it is being used. A buzzer can not be used without power, it is useful for alerting people when dangerous materials are in use, or in 7G’s case just to annoy the heck out of anyone surrounding you.

LED’s (light emitting diode):

What are they?

LED’s are lights that can come in assorted colours and sizes. When in use LED’s light up, they are used in flashlights and many more other types of lights. In my last project (nerve tester, see last 3 posts) I used 2 red LED lights, the are useful for warning people and many more useful technique’s.

LDR (light dependent resistor):

What is it?

LDR’S  are used everywhere, they are streetlamps, nightlights etc. LDR’s are practical household devices, they are used to guide, prepare and much more. LDR’s work when it becomes dark to resist the dark. So just as the sun goes down or the light in a bedroom is turned off, LDR’s turn on.