op-amp circuit

Small stereo amplifier,low power, less devices, IC TDA7025 is the main equipment. Operation of the circuit, the signal split into left and right through the capacitor coupling of C1, C2 is a variable resistor VR1 adjusts the strength of the input signals to bridge amplifiers power suppliers IC1-. IC2, serves to amplify the signal up, [...]

Inductors can be mimicked quite easily using operational amplifiers. The circuit shown here was developed to have an inductance of 1000 H (say, one thousand Henry) with good damping. Using this design you can build a resonant circuit with a center frequency of less than 1 Hz. The slow behavior allows you to use conventional [...]

This simple micro ampere meter circuit can help in measuring small currents in five ranges: from 1 µA to 10 mA. The meter is working in this way: the current being measured Ix shifts the input voltage resulting to an output voltage with an inverted polarity. The output voltage of the opamp CA3130 is proportional [...]