This conventional filter circuit is from American documentation from the 1990s. The operational amplifier admits an equivalent and the power supply must be symmetrical.
Found in an Electronics World of 1968 this circuit has a 40 to 12 000 Hz bandwidth providing a 1.9 Vpp...
This amplifier was obtained in an Electronics Now based on the LM1875. The circuit must be powered...
This timer controls two relays, each with a different timing, activated separately. The circuit is from...