I have built a metal detector with depending on frequency different.
Where I've finished fixed and variable oscillator.
In building the mixer(to get the difference) I've many problems.I decide to put the two signals in a diode to give multifunction and to get my signal I take it through LP filter but it doesn't work.
Then, I use op amp (Miller integrator) instead of LP filter. but also it doesn't work. where I think in that case the diode will not work because the voltage at op amp side is larger than it at oscillators side.
can you give me a solution for it? or alternative for mixing the two signals
Where I've finished fixed and variable oscillator.
In building the mixer(to get the difference) I've many problems.I decide to put the two signals in a diode to give multifunction and to get my signal I take it through LP filter but it doesn't work.
Then, I use op amp (Miller integrator) instead of LP filter. but also it doesn't work. where I think in that case the diode will not work because the voltage at op amp side is larger than it at oscillators side.
can you give me a solution for it? or alternative for mixing the two signals