View Full Version : Understanding a waveform

03-27-2007, 09:04 PM
I have two sonar sensors' pulse output wired into the same pin on an SX48. I range them seperately and never at the same time.. I isolated the pulse output pins of the sensors with· 1n914 diodes (It's what I had), While looking at the waveform from the sensor, it's a really nice squarewave, if I look at the waveform after the Diode the trailing edge slopes.. I assume it has something to do with the recovery time of the Diode and it's internal capacitance. What is a better diode to use than a 1n914 to square off my waveform again. Or is this not really a problem.


03-27-2007, 09:33 PM
I doubt changing the diode would help. You probably need a pull-down resistor after the diode. Something like 1K should give a nice clean falling edge.


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03-27-2007, 09:43 PM
OK Thanks for the Advice.