Differences
This shows you the differences between two versions of the page.
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iot:res:electronics [2015/06/22 01:47] madalina.tanea [Kirchhoff's First Law] |
iot:res:electronics [2015/06/22 01:50] (current) madalina.tanea [Button] |
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| ====Kirchhoff's Second Law==== | ====Kirchhoff's Second Law==== | ||
| Kirchhoff's Second Law states that the sum of the voltage in a circuit loop is equal to the power source voltage. | Kirchhoff's Second Law states that the sum of the voltage in a circuit loop is equal to the power source voltage. | ||
| - | {{ :iot:res:k2.png?300 |}} | + | {{ :iot:res:k2.png?100 |}} |
| Example: | Example: | ||
| {{ :iot:res:second_law.png?300 |}} | {{ :iot:res:second_law.png?300 |}} | ||
| Line 39: | Line 39: | ||
| A button, also called a switch, is an electric component that can break an electrical circuit by interrupting the current. | A button, also called a switch, is an electric component that can break an electrical circuit by interrupting the current. | ||
| When used in schematics, there are multiple possible symbols to depict it. | When used in schematics, there are multiple possible symbols to depict it. | ||
| - | {{:iot:res:button_depict.png?300 }} | + | {{ :iot:res:button_depict.png?100 |}} |
| - | {{:iot:res:toggle_switch.jpg?300 |}} | + | {{ :iot:res:toggle_switch.jpg?200 |}} |
| Also, the figure depicts an example of circuit that uses a switch. | Also, the figure depicts an example of circuit that uses a switch. | ||
| {{ :iot:res:button_example.png?300 |}} | {{ :iot:res:button_example.png?300 |}} | ||
| Line 56: | Line 56: | ||
| {{ :iot:res:button_correct.png?300 |}} | {{ :iot:res:button_correct.png?300 |}} | ||
| - | This time you will not have a short circuit because if the button is pressed there is the R resistor. The R resistor is called a pull up resistor// and the whole system is called a //voltage divider//. If the button is pressed our pin's value will be LOW. | + | This time you will not have a short circuit because if the button is pressed there is the R resistor. The R resistor is called a //pull up resistor// and the whole system is called a //voltage divider//. If the button is pressed our pin's value will be LOW. |
| You can also connect the resistor to the Ground. Now you have a pull-down resistor and the pin's value will be HIGH when the button is pressed and low otherwise. | You can also connect the resistor to the Ground. Now you have a pull-down resistor and the pin's value will be HIGH when the button is pressed and low otherwise. | ||
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| Whenever you connect anything to your board you must assure that the it is not powered up. Otherwise you might accidentally create a short-circuit and burn the board. | Whenever you connect anything to your board you must assure that the it is not powered up. Otherwise you might accidentally create a short-circuit and burn the board. | ||
| - | Only after you assured that everything is correctly connected, you may safely power it up.\par | + | Only after you assured that everything is correctly connected, you may safely power it up. |
