AC and DC Circuits

### Basics

#### Series and parallel circuits

• Consider the following image
• Voltage:
• In a series circuit, the total voltage is the sum of all the voltages.
• That is: $V_{output} = V_1+V_2+...$
• In the example, the voltage output would be 12V
• For a circuit with resistors in it, this means that the voltage drop across each resistor adds up to the supply voltage.
• In a parallel circuit, the total voltage is equal to the voltage in any circuit.
• That is: $V_{output} = V_1 = V_2 = ...$
• In the example, the voltage output would be 6V
• For a circuit with resistors in it, this means that the voltage drop across each resistor is equal to the supply voltage.
• Current
• In a series circuit, the total current is equal to the current from one battery.
• That is $I_{output} = I_1 = I_2 = ...$
• In the example, the output would be 20A
• For a circuit with resistors in it, this means that the same current flows through each resistor.
• In a parallel circuit, the total current is the sum of all the currents.
• That is: $I_{output} = I_1+I_2+...$
• In the example, the output would be 40A
• For a circuit with resistors in it, this means that the current flowing through each resistor adds up to the supply current.
• Resistance
• $R_{series} = R_1+R_2+R_3...$
• $\frac{1}{R_{parallel}} = \frac{1}{R_{1}} + \frac{1}{R_{2}} + \frac{1}{R_{3}} + ... + \frac{1}{R_{n}}$

#### Rectification

• This is the conversion of AC to DC
• For a Half-Wave rectification, a single diode is used to block the one direction of the AC wavelength.
• For Full-Wave rectification, four diodes are used to produce a current in a single direction.

* These four diodes are arranged as shown (This is known as a bridge rectifier):

page revision: 2, last edited: 07 Oct 2011 10:22