Datasheet

28
CIRC-11
.:Larger Loads:.
.:Relays:.
This next circuit is a bit of a test. We combine what we learned
about using transistors in CIRC03 to control a relay. A relay is
an electrically controlled mechanical switch. Inside the little
plastic box is an electromagnet that, when energized, causes a
switch to trip (often with a very satisfying clicking sound). You can buy relays that vary in size
from a quarter of the size of the one in this kit up to as big as a fridge, each capable of
switching a certain amount of current. They are immensely fun because there is an element of
the physical to them. While all the silicon we've played with to this point is fun sometimes you
may just want to wire up a hundred switches to control something magnificent. Relays give you
the ability to dream it up then control it with your Arduino. Now to using today's technology to
control the past. (The 1N4001 diode is acting as a flyback diode, for details on why it's there visit: http://ardx.org/4001)
2 Pin Header
x4
CIRC-11
Breadboard Sheet
x1
2.2k Ohm Resistor
Red-Red-Red
x1
560 Ohm Resistor
Green-Blue-Brown
x2
Red LED
x1
Relay
(DPDT)
x1
Arduino
pin 2
resistor
(2.2kohm)
gnd
(ground) (-)
Collector
Emitter
Base
+5 volts
Transistor
P2N2222AG
coil
com
NC
NO
Diode
(flyback)
Diode
(1N4001)
x1
the transistor will have
P2N2222AG printed on it
(some variations will have
the pin assignment reversed)
Transistor
P2N2222AG (TO92)
x1
Green LED
x1
.:download:.
breadboard layout sheet
http://ardx.org/BBLS11
.:view:.
assembly video
http://ardx.org/VIDE11
WHAT WE’RE DOING:
Parts:
The Internet
THE CIRCUIT:
Schematic