Monthly Archives: December 2011

More on Semiconductor Switch

Continued from yesterday’s article.  Here are the switches I compared.

Mechanical Push Switch (Tactile)

You hear click noises.


There are occasional pop noises.

Analog Switch

Not bad but click noise intermittently happens.


JFET Switch

 The most stable so far.

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Charge Pump with Arduino

Right: charged, left: normal 5V drive

A charge pump is a circuit that boosts DC voltage.  I tried to make a charge pump using Arduino to enhance power supply for a blue LED.  A blue LED typically has higher forward voltage.  Some ones go to 4V, so 5V-supply processors are slightly powerless to drive it.  Thus a charge pump helps to enhance blue LED brightness.

As you can see in the photo above, charged one is brighter.  The supply voltage was increased to 8V in this case.

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