Hi
can anyone help
I'm using an AD633JN analoge multiplier which is to expensive.
Can anyone suggest alternatives (Im using it as a sine wave phase detector)
many thanks
DPJ
hi
it's very easy to make an analoge multiplier
you can use two logarithmic amplifier then an adder then an anti logarithmic amplifier to make a multiplier.
with just four OP-AMPs and two diods or two transistors and it's very low cost.
with this theory:
x*y=exp(ln(x)+ln)
because ln(x)+ln=ln(x*y) and then exp(ln(x*y))=x*y
and making logarithmic and antilogarithmic amplifiers and an adder is very easy.
if you don't know what is a logarithmic amplifier
and you can not make this simple circuit
please email me to this address
kasra_ravanbakhsh@hotmail.com
Check the Analog Devices site. I recall they recently introduced a specific phase detector chip. It may not operate low enough in frequency for you though.