Based on Texas Instruments documentation, this circuit serves for sensor interfacing. The circuit is based on the LF411, but other operational ones can be used.
This non-inverting AC amplifier was found on a Popular Electronics. The setting applies to any...
This circuit supplies 5 V from two AA batteries. The output current is 4 mA, resulting in an 11 mA...
With this regulator we can have currents of up to 4 amps with 5V at the output. The transistor can be...