Two-tone solar buzzer (CB20493E)

This circuit was found in a 1991 publication. The transistor can be a general-purpose type.

Stepper Motor Control (CB21247E)
Found in an Electronic Design from the 90's, this circuit generates signals for stepper motor...
High Output Voltage Amplifier (CB6179E)
This circuit is from Mullard 1969 documentation. The circuit operates at a relatively high supply...
Noise Bridge (CB21785E)
This circuit combines several white noise generators for testing transmission equipment. The...