This circuit is from Mullard documentation from 1969. Transistors support current equivalents. Output transistors must be mounted on heat sinks.
This TTL decoder circuit for PC ports was found in a document from 1992. The power supply can be...
This circuit is from an old Popular Electronics, but it can be easily implemented nowadays, even...
The basis of this circuit is a CA3130 operational amplifier. The transistor can be BC548, and the...