The document describes a circuit built to test the operation of a relay. The circuit uses a transistor connected to a photoresistor, battery, and relay. When the photoresistor detects light, it allows current to flow through the transistor and activates the relay, demonstrating how it operates using an electromagnetic field to connect or disconnect a circuit. The circuit also includes an LED connected to the relay to indicate when it is active. The document states that this practice circuit is useful for testing electronic device performance and demonstrates how electric current can activate components like relays.

1. CIRCUIT TO TEST
THE OPERATION OF
A RELAY
Jahir Iván Alemán Ernesto Mares Sosa
Erick Eduardo Garza Loria
5ºA NOVIEMBRE 2012

2. 4. Escucha, interpreta y emite mensajes pertinentes en distintos
contextos mediante la utilización de medios, códigos y
herramientas apropiados.
4.5. Maneja las tecnologías de la información y la
comunicación para obtener información y expresar ideas.
8. Participa y colabora de manera efectiva en equipos diversos.
8.2 Aporta puntos de vista con apertura y considera los de otras
personas de manera reflexiva.

3. 11. Se comunica en una lengua extranjera mediante
un discurso, lógico, oral o escrito, congruente con la
situación comunicativa.
manera reflexiva.

4. Protoboard relay led
Transistor battery resistance 330 ohms
Photoresistance wires connection

5.  First transistor is connected as shown in the image
 After the relay is connected to the collector of
transistor
Then connects the photoresistance from the positive
of the battery to the base of transistor

6.  then connect a wire from the positive of the battery
to common and then connected the LED to the
right leg of the relay with a resistor to the negative
of the battery
 finally connect the battery to the wires
corresponding negative and positive

7.  This practice I found very useful
for testing the performance of
electronic devices
 This activity tests the operation of
the relay and how the passage of the
current it generates an
electromagnetic field which serves
as a magnet to activate the relay

8.  This practice we can demonstrate
the multiple functions that can
make the passage of electric
current