Wedneday week 3

Today we presented our projects and worked with the 555 timer and oscilloscope. The first thing i did was to build a simple 555 driver circuit to make an LED blink. The circuit is shown at right.
The two potentiometers fine tune the frequency and pulse width output by the 555, and the capacitors are the coarse adjustment. The larger the capacitor the lower the frequency.





I then replaced the LED with a piezo speaker and reduced the capacitance to increase the frequency to audio range. I played with it and viewed the output on the CRO, signal shown left A part of the class portion was to learn how to use an O-scope, but since I already knew how, I spend the time playing with more advanced functions for the 555.

I was partially successful in getting the 555 to control a servo position. I did some basic calculations to get values for resistance and capacitance to get the correct on and off time of the signal. By rotating the larger potentiometer, the position of the servo would change, but i couldn't get a full range of motion.