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How does the speed controller potentiometer control the forwards and backwards motion as well as the speed? Where can I find circuit diagrams for controllers? Most info on the web shows a wiring diagram to connect the motor / controller / battery - none on the theory behind the controller.
my scooter is ew38 ewheels it went into the swimming pool batteries are good will not roll seems like motor locked up has power when you turn switch on but nothing works? I AM IN CALIFORINA .
Peter Skilton just for starters I’d recommend you read through this Development of a Control System for a Power Wheelchair Trainer. It has a lot of really good information (including the motor controller).
Firstly the movement of the pot is monitored in most controllers by a embedded processor such as a PIC 16 right upto the latest embedded ic’s , they can also be found in Car E.C.U. Once the processor is satisfied that Brake, Motor etc are connected and given the right resistance, It will activate a relay and a mosfet power-driver known as a HIP4082 etc,. I suggest you lookup the PIC chips and look at application notes regarding driving a electric motor , the theory will be explained in detail.. Most controllers can be repaired cheaply.. Regards Rob GewizRepairs.co.uk
my handicap scooter got wet controller went out had it in the shop but could not fix it and they put another controller in but still dose not work?
Hi Jack. Your scooter drive system has multiple parts. The first thing to consider is - is the machine completely dead? If so, suspect the batteries or cabling - check with a multi-meter. If they check out OK, then it is the controller or the plugs associated with it. The motor - the strongest item in the system is unlikely to be affected by rain water except for the clutch which has a micro switch on it. If that has burnt out then the controller should send a signal to a light on the handlebar cluster that flashes a number of times. You need to count the number of flashes and Google the scooter maker and ask him for a fault chart. If the machine is not completely dead then the control head at the handle bars has a variable resistor (normally 5K) and some fixed resistors and diodes. Check with a multi-meter. You say that the shop has replaced the control box - actually they are very water tight and if it is only rain water, unlikely to be faulty - if your scooter actually went under water in a flood then it is probably a ‘write off’. So …. if its dead - check power source system (i.e. battery circuits), if not dead - suspect circuit in wiring cluster at the handle bars. If you give us more information on what happened maybe we can be more specific. What country are you in? What make is the scooter? Peter Skilton.
