This circuit provides an audible signal when testing a TTL circuit. The circuit is from an old documentation, being fed with the 5V of the circuit under test.
We find this circuit in American documentation from the 1980s. The accuracy of the circuit depends on the...
The presented circuit uses a symmetrical power source to supply an amplifier with the LM139 or...
High quality sound can be obtained from this transistor amplifier. The output transistors must be...