Metal Detector

[Admin]

This thread is for the discussion of the Metal Detector circuit.

Circuit URL:
http://www.555-timer-circuits.com/metal-detector.html

Note: This circuit is considered working but it is missing written content. Help us complete this circuit for others by suggesting your own text and imagery.​

 

[Justin]

Is this a proper beard board layout for this circuit?

 

[shermz]

hi, I have the interest in the in the circuit but I do not know maybe the principle operation, like the purpose of each capacitor and the oscillating frequency of the circuit

 

[Justin]

I've tried making the circuit based upon my breadboard layout. I've based the breadboard layout from the circuit diagram from this site.

• Here is the circuit diagram I based the breadboard layout on.
• Here is my first attempt at making the breadboard layout.
• Here is my second attempt at making the breadboard layout.
• Here is my speaker

The two red and black wires you see on the right are the speakers wiring. Could it be that because of my speaker o.1 Wattage rating that it does not work? Or does anyone see something wrong with my breadboard that is currently making this circuit not function proper. I'm so confused.

Edit: I just tried to base my breadboard creation off of the circuit diagram and am very sure its correct. Here is my third attempt at making the breadboard but it still does not work. I calculated the Wattage of this circuit to be 0.00172340425531914893617021276596 Watts. My speaker can handle 0.1, so it can't be the speaker.

Edit: Switched around some capacitors (Negatives were facing the wrong way) and moved pin #3's wire to the proper place. Every time I plug in my speaker it makes a sound, but does nothing when metal is brought near it, like a metal detector should. I even hooked it up to an oscillator and nothing was changing when metal was brought close or taken away. The speaker does work, I've tested it properly. Maybe because its only 0.1W and not 0.25W like the parts list suggests, but that shouldn't affect the outcome. Could somebody help me with this? Here is my fourth attempt at bread boarding this circuit.

Edit: Found what I did wrong, I actually bought the wrong choke (It's close to whats needed, but not enough) so I won't be able to try this out until later next week.