This circuit is from a 1977 Signetics integrated circuit manual. The output transistors can be BD136 and BD237 and the symmetrical supply can be from 6 to 12 V. The voltage gain is 10.
We found this 3-digit digital odometer for bicycles (or another application) in a 1995...
This circuit was published in a 1977 English magazine, but remains current, since we can assemble it...
In the figure we have the configuration of series regulator protector suggested by Motorola in 1968...