How to control the speed of 1.5 Volt motor?
Most 1.5V motors are probably DC brushed permanent magnet motors. To control the speed you can either reduce the voltage (eg to 1V) or use Pulse Width Modulation (switch the 1.5V on and off rapidly so that the average voltage is less).
doesn't really work too well as it severely limits the current to the motor as well and it looses its torque power
That's why PWM is the best way to control the speed
Separate names with a comma.