Ohm's Law: Difference between revisions
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==Voltage '''V'''== | ==Voltage '''V'''== | ||
Voltage is measured in [http://en.wikipedia.org/wiki/Volt volts]. (V) There are two basic type of voltage:<br/> | Voltage is measured in [http://en.wikipedia.org/wiki/Volt volts]. (V) There are two basic type of voltage:<br/> | ||
*AC [http://en.wikipedia.org/wiki/Alternating_current Alternating Current] | *'''AC''' [http://en.wikipedia.org/wiki/Alternating_current Alternating Current] | ||
**Example: | **Example: | ||
**The voltage of a typical wall power outlet in the United States is 120 volts AC (VAC). | ***The voltage of a typical wall power outlet in the United States is 120 volts AC (VAC). | ||
*DC [http://en.wikipedia.org/wiki/Direct_current Direct Current] | *'''DC''' [http://en.wikipedia.org/wiki/Direct_current Direct Current] | ||
**Example: | **Example: | ||
***The voltage of a typical AA battery is 1.25 volts DC (VDC). | ***The voltage of a typical AA battery is 1.25 volts DC (VDC). | ||
Revision as of 04:24, 28 October 2012
Ohm's Law
Ohm's Law is a formula that relates the basic electrical properties. The common formula for Ohm's Law is:
- V=IR
- Voltage = Current x Resistance
- V=IR
Ohm's Law Diagram
The following diagram shows the relationship between the various electrical properties.
Voltage V
Voltage is measured in volts. (V) There are two basic type of voltage:
- AC Alternating Current
- Example:
- The voltage of a typical wall power outlet in the United States is 120 volts AC (VAC).
- Example:
- DC Direct Current
- Example:
- The voltage of a typical AA battery is 1.25 volts DC (VDC).
- Many Integrated Circuits require 5 volts DC (VDC) to power them.
- Example:
Current I
Current is measures in amps (A). Current is often measured in many electronic circuits is measured in milliamps (ma). A milliamp is one thousandth of an amp (0.01A).
Resistance R
Resistance is measured in ohms (Ω).
Power P
Power is measures in watts (W).
LED Calculator
Use these calculators to calculate the resistor needed to include in a circuit with a LED.
Single LED
LED Calculator for 1 LED.
Array of LEDs
LED Calculator for an array of LEDs.