Part 12 (1/2)
For Further Information
Check with your leader, then ask your power supplier or a local electrician to tell you about safe electrical wiring, connections and fixtures
+-------------------------+-------------+------------------------+ |Hazard | Location |What I Did | +-------------------------+-------------+------------------------+ |_Loose prong on la_ | +-------------------------+-------------+------------------------+ |_Cracked insultor on |Back of house|Notified power _ | |_service wire in house | |supplier_ | +-------------------------+-------------+------------------------+ |_Conduit not securely |Basement by |Notified parents_ | |_clamped to box |fuse box_ | | +-------------------------+-------------+------------------------+ |_Extension cord, old and |Base |rubber-covered one and_ | | |_machine |protected it from _ | | | |_water_ | +-------------------------+-------------+------------------------+
LESSON NO B-10 Credit Points 3
HOW ELECTRIC BELLS WORK--FOR YOU
When was the last tie like ”You're wanted on the telephone,” ”There's someone here to see you,” or ”There's a car in the driveway,” to someone around your place? Did you have to walk or run some distance and perhaps shout, too, to be heard by the other person? Perhaps you had to stop some other work, or interrupt your favorite kind of fun, to do this bit of e is like one of those reat, then perhaps you can use bells or buzzers or both to do soh a bell or a buzzer can't talk, it can convey a e
What to Do
1 Learn how bells and buzzers work, and learn about the many different kinds
2 Plan and install a bell system for your home or farm
Bells and Buzzers Can Tell a Lot
Electric bells and buzzers use the saraph systeh not as important today as it was before radio, telephone, and teletype becaraph is still in use
Bells and buzzers, however, are very common and have many uses They are most often seen in the form of doorbells, and rare is the new home that does not have one or more Service stations have bell systeas pu time is completed Children are called to and released from school classes by means of bells and buzzers
Also, various alaret up, or even that the place is on fire, or that a burglar is trying to break in!
Let's find out how bells and buzzers work, what different kinds there are, the different ways you can control them, and how you can put them to work for you
You'll find that buzzers and bells can help you with your 4-H projects, and with the proper controls, can be your eyes and voice in a dozen places at once
Why They Buzz or Ring--Electronetism
If ere to look at an electric bell with the cover off, we'd find that it would be very ure 1
A push on the button, which is just a switch that is nor, sends the current froh the circuit
[Illustration: Figure 1]
You will see that the current passes first through two small coils of wire, and each coil has at its center a piece of soft iron called the core When the current is on, the core beconetized and attracts another piece of iron called the ars the bell, but it also breaks the current by pulling the spring away from the screw on its return to the power supply