ELT202 LAB. This is the "Vertical Input" circuit for a basic oscilloscope which is used in many instruments today. Use both switches to change the triggered slope. The waveform represents the input waveform. (will cover 1X and 10X probe circuits in other sections). The adjustable voltage divider is the set the "trigger level". Basically changing the trigger level will have the comparator state change to "view only the area which is relevant to the condition:
For example
OPERATION 1.) Setting the switches to allow the potentiometer voltage to go into the comparators reference pin [-]. The comparator would be ON when the input waveform [+] is above the reference voltage.
OPERATION 2.) Setting the switches to allow the potentiometer voltage go to the comparators [+] and the input waveform going to the comparators [-] would have the comparator ON, only when the input waveform was below the the [+]
The components after the comparator (capacitor, resistor) forms a RC high-pass filter. Allowing only a short spike to occur when the comparator changes states. The zener diode regulates the peaks to 3.3V and shunts the remaing voltage to ground.
I will be building each stage separately. You can follow along each stage as I learn them. Then will build the entire thing all connected together as a final conclusion to this series. The final assembly could be connected to a CRT' horizontal and vertical input amplifier and be displayed on an older type TV to view waveforms.
