The electrical signals from the transducer, Sometimes it is valued less too, For input to the circuit to convert signals from analog to digital.To achieve a satisfactory. We need a power amplifier, who can tell the strength of the input signal is simple.This can extend the input signal from the transducer is 10 times and 100 times.
The circuit consists of op-amp IC1 No. 741, To give the appearance of non-inverting circuit, R1 is configured input impedance switches.In this the 75 kilo ohms, negative feedback circuit consists of R3 or R4 together with R2, which defines the gain of the circuit.
The gain of the circuit is equal.
R2 + R3 / R2 When S1 scroll at the top.
R2 + R4 / R2 When S1 scroll down below.
When the value provided in the circuit will gain about 100 and 10 respectively (actually supposed to be 101 and 10.1).
Power supply for this circuit requires two sets of power supply positive and negative, which was in the range of positive, negative 6 volts to the positive, negative 15 volts, in this value-add, subtract 9, because available with 9-volt battery immediately.