metal sensor
Posted: Sun Nov 27, 2011 10:19 amcan anyone suggest me a suitable metal sensor can interface with SK40C with pic16f877A in addition of servo motor.
Cytron Technical Forum
metal sensor
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Posted: Sun Nov 27, 2011 10:19 amRe: metal sensor
Posted: Mon Nov 28, 2011 8:01 pmRe: metal sensor
Posted: Mon Nov 28, 2011 8:20 pmwow.. its great... but just wanna ask.. did this circuit can connect with sk40c.. because i'm using pic..
Re: metal sensor
Posted: Mon Nov 28, 2011 8:32 pmshould be ok, just remove the speaker and connect it into the IO pin. But the sensor output is a square wave, it differs as it detects metal.
Re: metal sensor
Posted: Mon Nov 28, 2011 8:58 pmHow to detect metal with that circuit? I mean which one is the "sensor" in the circuit diagram? The inductor, or capacitor, or speaker, or...? 
Re: metal sensor
Posted: Mon Nov 28, 2011 9:24 pmThe site http://www.555-timer-circuits.com/metal-detector.html says that the sensor is the inductor/choke there.
Re: metal sensor
Posted: Tue Nov 29, 2011 7:14 amSince the circuit is simple, you might just construct it and see the effect to judge whether it is suitable for your need. I guess the circuit is outputing a continuous tone and when the inductor is brought near a metal, the inductance would change and thus changes the pitch of the tone. So you need some kind of op-amp circuit with rectified output to convert it to a logic H or L when the wanted tone is detector. You might also need a band-pass filter between the 555 and the op-amp to select the frequency that you're interested.
It is a simple circuit so the sensitivity may not be satisfactory but anyway it is a good start.
Allen
It is a simple circuit so the sensitivity may not be satisfactory but anyway it is a good start.
Allen