Action and Use of Circuit Components

• A potential divider divides the voltage into smaller parts.

• To find the voltage (at V~OUT~) we use the following formula:

• A variable potential divider (potentiometer) is the same as the one above but using a variable resistor; it acts like a potential divider, but you can change output voltage.

• Input Transducers:

  • Thermistor: input sensor and a transducer. It is a temperature-dependent resistor. At higher temperature there is less resistance.

    

  • Light dependent resistor (LDR): input sensor and a transducer. When light intensity increases, resistance decreases.

    

• Relays:

  • A switch operated by an electromagnet

• Normally closed relay: when coil not energized, switch is closed, completing circuit

• Normally open relay: when coil energized, switch is closed, completing circuit

• Diodes:

  • A device that has an extremely high resistance in one direction and a low resistance in the other, therefore it effectively only allows current to flow in one direction

  • Forward bias is when the diode is pointing in the direction of the conventional current and reverse bias is the opposite

  • It can be used in a rectifier; turns AC current into DC current.