Tim Hedegaard
New Member
Hey everybody
I am currently engagede in makeing a projekt about an PI metal detector.
It is my last semester of my IT and Electronics study in Denmark, and i have run into some problems concerning my construction.
I am trying to make this one (follow link to schematic)
Surfmaster PI Metal Detector Schematic Diagramwhich i have modified as follows:
*Q1: BC556
*Q2: BD140-16
*Q3: TIP122
* U1: TLC555 (LinCMOS timer IC)
* U2: NE5534 (Single Low Noise Op Amp)
* U3: 2x TLo71C (Low Power Op Amp)
* U4: MC14093B (Quad Schmitt trigger)
* U5: 78M05 (5V Positive Voltage Regulator)
* U6: LTC1044 (CMOS switched-capacitor voltage converter)
* U7: CD4066 (Quad Bilateral Switch)
And other small changes that isn't that important.
My construction works as well as I have hoped with one huge problem U7/D do not work as I would like it to, if I am correct it should activate when no metal is detected and therefore be connected to gnd and I would hear nothing in he headphones?
But it does not work, I hear a constant tone that I can change the pitch of but not erase, I still hear a clear change in the pitch when I move my coil close to a metal objekt and so I works but I would love to get the damn switch to work.
I hope some of you out there can help me, I have more information on the projekt if needed, so please if somebody knows how to cure me of the splitting headarche I get from using my metaldetector.
Thank you
I am currently engagede in makeing a projekt about an PI metal detector.
It is my last semester of my IT and Electronics study in Denmark, and i have run into some problems concerning my construction.
I am trying to make this one (follow link to schematic)
Surfmaster PI Metal Detector Schematic Diagramwhich i have modified as follows:
*Q1: BC556
*Q2: BD140-16
*Q3: TIP122
* U1: TLC555 (LinCMOS timer IC)
* U2: NE5534 (Single Low Noise Op Amp)
* U3: 2x TLo71C (Low Power Op Amp)
* U4: MC14093B (Quad Schmitt trigger)
* U5: 78M05 (5V Positive Voltage Regulator)
* U6: LTC1044 (CMOS switched-capacitor voltage converter)
* U7: CD4066 (Quad Bilateral Switch)
And other small changes that isn't that important.
My construction works as well as I have hoped with one huge problem U7/D do not work as I would like it to, if I am correct it should activate when no metal is detected and therefore be connected to gnd and I would hear nothing in he headphones?
But it does not work, I hear a constant tone that I can change the pitch of but not erase, I still hear a clear change in the pitch when I move my coil close to a metal objekt and so I works but I would love to get the damn switch to work.
I hope some of you out there can help me, I have more information on the projekt if needed, so please if somebody knows how to cure me of the splitting headarche I get from using my metaldetector.
Thank you
