This is a Nand Gate TTL By DR. Elijah Mwangi ,Kenya.
the 50K resistor acts as the small current load to give a stable output voltage.
The circiut gives a Logic high outut of 3.7V which lies in the 3.4V - 3.7V range .
And a logic Low of just 21.2mV, also in the 0V to 0.3V range.
