Voltage Level Detector (CB22135E)

We found this circuit in an English documentation from the 80's. Transistors are general-purpose types.

TTL binary adder (CB22430E)
This circuit is based entirely on TTL gates. The circuit must be powered by a voltage of 5...
Beacon Transmitter (CB11952E)
This transmitter operates in the FM band emitting beeps that can be picked up on a common radio at...
Siren Oscillator (CB8449E)
This circuit was found in a 90s European documentation. The circuit already includes a powerful...