Hi guys,
This is an image from the Maxbotix site, a circuit recommended for removing electrical noise. I was wondering whether it is safe to replace the 100ohm resistor with a diode (with a low forward resistance), so that it can double up as a reverse voltage protection element.. ?
The forward resistance of a diode im using is around 600 ohm. Will it significantly changes the noise filtering performance? (different timeconstant RC )?
Can I make up for the change by using a different capacitor?
Any sort of help is much appreciated.
Why would you want a reverse
Why would you want a reverse protection element in the first place? Are you worried about connecting the power lines in reverse?
Replacing the 100Ω resistor with a diode will cause a voltage drop of around 0.7V, which may reduce the performance of the sensor - diodes are non-Ohmic devices, and as such you can’t really label them with a resistance.
The noise filtering effect of the capacitor itself will not change, but the resistor does decrease the rate at which the voltage seen at the +5V pin changes due to noise/spikes.
In the end the sensor will still work even with no resistor or capacitor, but they do improve the circuit’s resistance to interference on the power lines.
Just worried
Sadly, I lost one EZ1… the most probable cause being a reversed power supply (it was a messy setup with lots of dangling wires… of the same colour… ). Got a new EZ4 now…
Anyways there is nothing wrong in being safe right. The Maxsonar LV series works even with 2.5V so i guess it wouldnt be a great drop in performance… do correct me if I’m wrong.
Later I thought of having a diode before a 7805 but that just seemed dumb (my battery plugs in in just one way only)
Or maybe I’ll chuck the whole thing and just learn to be tidy and careful. Thanks for your support nevertheless.
