The circuit is from 1968, but we can use a modern one like the 741. The symmetrical power supply voltage (two batteries or source) can be from 9 to 12 V.
Found in Motorola documentation from the 90's, this circuit charges the capacitor with a constant...
This circuit has two high-impedance inputs. The gain is high and more inputs can be added. Use a...
We found this circuit in the Philips Databook of 1990. The circuit is indicated for low-cost...