If you have ever hacked around with electronics, especially robotics, you have probably come to a point where you wanted to compare two analog values. Of course, you could always use a microprocessors ADC but if all you want to know is which value is higher, there is a much more elegant solution — the Comparator.

Basically the comparator is a glorified Op-Amp and when used in its most basic arrangement it can act as a one bit ADC converter. Just attach two analog voltages to V+ and V- and if V+ is greater than V- the chip returns a logic high (+5V). Otherwise, it returns logic low.

The real trick to using this is to remember to use the a pull-up resistor at the output.

Don’t you feel smarter already?

[pinout provided by the good people at National Semiconductors]