potentiometer-switch for 24V electric motor

Can anyone help me, I'm an English musician with a 24V motor underneath my electric street-music sound system (recycled disabled persons vehicle).
Unfortunately the original electronic controll system has been removed so at the moment the only way for me to get the motor to work is when I connect it directly to the 24V power supply (2x12V Gell batteries) via the 70Amp fuse which was still connected. This unfortunately gives me such a sudden surge of power, (0-25 kmh in 1 second) that I'm afraid I could easily break the legs of anyone in the streets if I'm not carefull.
I have absolutely no Idea whatsoever about electronics, but I presume I need some kind of potentiometer right ?
Please tell me what I need and where I can get it, in order to protect the health of lots of innocent people in the pedestrian zones of Europe.
The simpler the solution the better !!!
many many thanks,
Mark Gillespie

Mark, the simplest solution is to get an electronic controller (second hand?), really. If a potentiometer would work satisfactorly, all electric wheelchairs would have them. There's way too much power involved to use ordinary potentiometers if you wish to control the voltage to the motor directly with one. Custom built potentiometers to handle the motor current might be rather expensive.
Also, it would be very wasteful of battery energy at low speeds.
Perhaps you could investigate along the lines of the step type controllers they use on electric trolling (boat) motors, they look simple enough but they would give you a set top speed range rather than a smooth acceleration.
Klaus

Hi Mark,

Klaus is right, these motors are controlled with pulse units.
They are called 'Pulse width modulation' units.
They usually will run forwards or backwards,
the control of the motor is very gentle and positive.

Such units are available ready made at quite reasonable prices.
24v is typical.

Regards, John

Pulse width modulation

Thanks for the advice, I will now go for a look in the www for suitable "pulse width modulation" units.