Devices ENTC 210: Circuit Analysis I Rohit Singhal Lecturer Texas A&M University

Administrative Lab?

Battery Chemical Reactions to produce potential difference  Alkaline and lithium-iodine primary cells  Lead Acid secondary cell  Nickel-Cadmium Secondary cell  Nickel-Hydrogen and Nickel-Metal Hydride Secondary cells Solar Cells

Power Supply Used very frequently in all devices.  Transform the AC supply into a lower voltage  Rectify it (?)

Current Sources Supplies a fixed amount of current  It is the dual of the battery In a battery voltage is constant, but current drains out

Ammeters Device to measure current The wire in which current is to be measured is broken up, and are joined via an ammeter. What should be the resistance of the ammeter?

Voltmeters Devices to measure voltage Connected in a parallel fashion across the device where there is a need to measure potential difference. What should be the resistance of a voltmeter?

Ohmmeters Used to measure the resistance of a device. Connected across the two pins of a resistor Also used to check the continuity of networks.

Wattmeters Used to measure the dissipation of power in a circuit element. Includes both an ammeter and a voltmeter. Displays the multiplication of both measurements.

Fuses and Circuit Breakers The power supply to the homes is not ideal. If it goes above a specified level, it can burn the devices. May result in Fire or Smoke. Fuse wires melt if they experience a large current. In a breaker, a large current results in a large enough strength in an inbuilt electromagnet to draw the switch open