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The DC throttle design has been popular for it's low speed control. Designed in about 1972, and called the "Mallory Throttle" it has been the basis of many throttles since.
One popular version is the 'Cool Crawler' which this roughly equates to. The output voltage is DC with a pulse on top reducing with a higher speed and derived from the mains power frequency. It is a gentle pulse and will not harm a delecate motor (so claimed).
This version can be mounted in a smallish plastic box and carried round, tethered by the power in and out cable. There is overload limited to about 3 amps.
The top speed can be trimmed by the variable 'top' potentiometer, there is progressive braking on one push-button and emergency braking on the other. Momentum is controlled by a separate potentiometer.
---- Running report
Very good slow speed operation. Will start slow too. Some control dead band. Noticable feedback that keeps the speed up when running up hill. Good speed memory if you want to use a 'Go' button.
The DC throttle design has been popular for it's low speed control. Designed in about 1972, and called the "Mallory Throttle" it has been the basis of many throttles since.
One popular version is the 'Cool Crawler' which this roughly equates to. The output voltage is DC with a pulse on top reducing with a higher speed and derived from the mains power frequency. It is a gentle pulse and will not harm a delecate motor (so claimed).
This version can be mounted in a smallish plastic box and carried round, tethered by the power in and out cable. There is overload limited to about 3 amps.
The top speed can be trimmed by the variable 'top' potentiometer, there is progressive braking on one push-button and emergency braking on the other. Momentum is controlled by a separate potentiometer.
---- Running report
Very good slow speed operation. Will start slow too. Some control dead band. Noticable feedback that keeps the speed up when running up hill. Good speed memory if you want to use a 'Go' button.
LINK TO IMAGE - cab-cc-1.gif
Circuit Schematic
