58 lines
2.2 KiB
Markdown
58 lines
2.2 KiB
Markdown
# Flip-Flop
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## Astable multivibrator (sometimes called "Flip-Flop") Circuit
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<!-- Other fromat for embedding images:  -->
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<img src="Astable_Flip-Flop_Circuit_Breadboard.jpg" alt="Breadboard" width="500">
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<img src="3D.png" alt="PCB" width="374">
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<br/>
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### Blinks, but also makes square waves
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A great candiate for a soldering workshop becuase it is gratifying with the blinking LEDs. There is more. It creates a square wave that can be observed with an oscilloscope. Also, even if sine waves are preferred for producing radio frequency (RF), the project is a very good entry point into exploring oscillators, a corner stone in generating RF.
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### Parts
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Parts required to make the flip-flop circuit are:
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- 2x LEDs
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- 2x 10 μF capacitors
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- 2x 470 Ω resitors
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- 2x 100 kΩ resistors
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- 2x BC547 transistors
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> [!NOTE]
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You can choose LEDs of any color.
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### Assembly
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You can use Fritzing files to print the PCB by yourself or you can have the circuit board printed for you for a fee, for example by uploading the .fzz file to https://aisler.net/<br/>
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Included are also Gerber Files (.zip) for printing by other board manufacturers, like JLCPCB (jlcpcb.com) for example.
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Attached are images and a file that can be opened in the Fritzing software (from https://fritzing.org/) to view the schematics, inspect or modify the circuit if desired. <br/>
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> [!TIP]
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> Fritzing also generates a breadoard view, a picture of which is also attached: the project can be made without a PCB.
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### Workings
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Q1 and Q2 are the BC547 transitor. Alternatilvy the equivalent 2N2222A can be used, it has slightly more gain than the BC547.
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> [!IMPORTANT]
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> If you decide to use the 2N2222A, you will have to mount it rotated 180 degrees as it's pin out is the other way round than that of the BC547.
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The blinking interval is determined by the values of the two 100 kΩ resistors and that of the two capacitors as per the formula: T = R x C
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Example values:
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- 100 kΩ x 10 μF = 1.0s
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- 10 kΩ x 10 μF = 0.1s
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- 100 kΩ x 1 μF = 0.1s
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> [!NOTE]
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> J1, J2, J3 are optional. Use them to pick up the square waves and display them on a oscilloscope. J3 is ground.
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### Intellectual property (IP)
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This work is dedicated to the public domain.
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