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General Category => Your projects => Topic started by: kam on May 12, 2009, 23:16:45 PM

Title: Rotating wheel up/down counter
Post by: kam on May 12, 2009, 23:16:45 PM
This is a project someone asked for help from another forum. I answered but i had to upload an image. There was no upload capability therefore i open this post. After all, is a nice circuit. And someone else here had asked before about a solution like this. http://pcbheaven.com/forum/index.php/topic,394.0.html (http://pcbheaven.com/forum/index.php/topic,394.0.html)

His idea was to have a wheel rotating. Then, he had to have a counter that counts UP when the wheel rotates CW and counts DOWN when the wheel rotates CCW. He found a solution with a mechanical switch, 2 ways. Like the attached aaa.jpg (first).

When the wheel rotates, the pin attached to the wheel will push the switch up or down, according the rotation. Then he had this circuit taken from a source. Is an up down counter circuit with CMOS. The circuit is the bbb.gif (seccond).

He asked for a way to link those two and work. Then, here is the real reason of the post. I had this drawing drawn for him. The circuit is the ccc.jpg (third).

I suggested the switch debouncers from here (http://pcbheaven.com/wikipages/555_Circuits/?p=0#7)
The transistor (2N2222, the cap, the resistor and the switch must be removed from the circuit.

I have not yet tested the circuit. Hopefully it will work.