Electrical Charge Carriers

• Electrical current is the electrical charge transferred per second
• Direct current flows in one direction and has one value
• Alternating current constantly changes direction and value
• A source for direct current is batteries
• A source for a.c current is mains electricity
• Mains electrical voltage is 230V
• Mains electrical frequency is 50Hz
• Peak voltage is the maximum voltage of alternating current
• Quoted voltage is

  • always less than peak voltage
  • the voltage measured by a voltmeter
• d.c and a.c with the same quoted voltage will supply the same power
• Current flows from the negative power terminal to the positive power terminal