CLICK HERE FOR INDEX PAGE

SYSTEMS PREPARATION QUESTIONS 2008 - 3

V. Ryan 2008

 

The Theme Park owner has commissioned a model clown. The aim is to frighten younger visitors. A motor inside the clown drives the arms up and the arms return to their original position when the motor is off The motor is the output to a 555 timer circuit. The circuit also produces sound as the arms move.

 

There are two types of 555 timer. What is the name of the 555 circuit shown below?

   
CIRCUIT NAME: ______________________________________
   
ANSWER
   
CIRCUIT NAME:  555 ASTABLE
   
Label the components on the circuit diagram below (A TO G).
   
ANSWER  
 

The relay is causing major problems because an important component is missing. Name the component and draw its symbol in the correct position on the circuit diagram above.

   
COMPONENT NAME: ______________________________
   
ANSWER
   
COMPONENT NAME: DIODE
   
What is the function of the component ?
 
 
 
 
   
ANSWER
   

The diode protects sensitive components such as the transistors from back E.M.F. When a current to a relay is removed the relay can emit current stored in its coils. This can be sent the wrong way round the circuit damaging components. The diode operates like a one way valve preventing this from happening.

     

CLICK HERE FOR ELECTRONICS INDEX PAGE

     
 
Google
 
Web www.technologystudent.com