Other Parts Discussed in Thread: LM339
Thank you in advance for any assistance you can provide.
I'm a mechanical engineer but have a fairly general understanding of electronics and have designed several circuits that appear to work okay. Having said that... my plan is to design a small circuit using TI's LM393 comparator in a simple proximity detection circuit. The detector outputs a DC range between 0V and 5V as range increases (from 0cm to 100cm). I want to limit detection to about 60cm (roughly 2 feet) and ignore anything greater than that distance. So... my thought is to use the LM393 with a reference voltage of 3 volts on the - input and let the + input range from 0 to 5 volts. If I understand the comparator correctly, the output (with a pull-up resistor) should be low until the + input reaches and exceeds 3 volts at which time it would go high. Am I correct in this assumption? Also, I'm a bit confused about what Vcc needs to be if the + input can go to 5 volts. Does it need to be 7 volts or greater? (Vcc plus 2 volts)? Or, can Vcc also be 5 volts?
Thank you again for your help. My apologies if the questions are really basic.
Tim Anderson