This circuit was found in General Electric's 1965 documentation. It appears elsewhere on the site. The SCR and the diodes must be in accordance with the motor current.
This control for 12 V drills was found in a 90s Elektor. The components are current, and Q1 can be...
Found in an old English publication, this circuit applies to the 240 V network, but can be changed to...
This circuit was found in a 90s Popular Electronics. With it, using a 4066, it is possible to...