This Motorola circuit uses only one transistor. The circuit is from 1965 documentation. The transistor must have a collector current rated at least to 12 A.
An OR gate can be improvised using NAND gates of a 4001 as shown here. The diodes are...
This circuit was obtained in a 90s Popular Electronics. In the table the values of the components...
General Electric suggests this circuit in an 80's documentation. The circuit makes use of PUTs...