This circuit is from old documentation, but it can be implemented with more modern equivalent components. The transistor can be the TIP31 with a heatsink and the 1N4002 diodes.
This circuit was found in a 1974 publication. It provides a tone indication of the temperature sensed by...
This is a simple rheostat circuit for motor control that works with voltages from 6 to 12 V. The...
This circuit with TTL compatible output was found in a 1968 US documentation. The circuit is...