Fyp2 - Week 7

RELAY DRIVER

• C547 transistor used as a switch for controlling the operation of the relay
• If there is voltage at the transistor base> 0.7V the transistor will be in the "ON"
• Current flows from the resistor, transistor base to ground.
• 12V current flow from the source to the collectors of transistors and thus to ground will cause the resulting magnetic field at which the relay coil's magnetic field will attract the "contact relay" from the "Normally close (NC @ OFF) to position" Normally open "(NO @ ON).
• If the voltage at the transistor base <0.7V the transistor will be in the off state. There is no current flow from the collectors of transistors to ground causes the relay Normally positioned close @ off