changing the polarity at the motor

[weirdeh]

Hey It has been awhile since I posted and i did search the forum first but just can not seem to find the answer.
I have a new need to have the 3 wheel reverse trike back up. (see photo) I just bought a new controller last year and really don't want to buy another one. need either a simple diagram to be able to use a couple or three relays or solenoid to change the polarity after the controller. top speed is only about 5 km/h . running 24volt power chair motor with built in reduction gears. can not remember what it draws for amps but I recall the motor was never fed more then 14 volts by the controller.

 

[weirdeh]

the motor is a Shihlin Electric and there is 4 wires coming out two are for the non working brake two of course are positive and Negative the other two are both white and I have no idea what they are for (not that I have looked either) anybody have one of these motors? I have tried for a couple of years to get an answer out of the people at SEEC but they don't answer english emails I guess.

 

[bobmcree]

Hey It has been awhile since I posted and i did search the forum first but just can not seem to find the answer.
I have a new need to have the 3 wheel reverse trike back up. (see photo) I just bought a new controller last year and really don't want to buy another one. need either a simple diagram to be able to use a couple or three relays or solenoid to change the polarity after the controller. top speed is only about 5 km/h . running 24volt power chair motor with built in reduction gears. can not remember what it draws for amps but I recall the motor was never fed more then 14 volts by the controller.

are you sure your motor will work properly in reverse? if it coasts forward without loading the bike it probably has a built in freewheel and cannot be reversed. assuming it can be and it is a brushed motor, you need a DPDT relay heavy enough to take the motor current. 40A automobile relays will not likely hold up but will work for awhile, but you could use 2 SPDT relays to make a DPDT. Most of these relays have only one 40A contact and the other is rated much lower. Connect the motor to the common terminals, then connect the battery to one pair of output terminals in one polarity and to the other set in the opposite polarity. this way the motor is connected to the battery in reverse directions depending on the position of the relay.

this diagram represents a dpdt relay with output b selected. connect battery - to out1a and out2b, then battery + to out2a and out1b then connect the motor to com1 and com2. connect the motor so it goes forward when the relay coil is not energized so that if it fails you can still go forward. two spdt relays with the 12v coils in series will run off 24v so that might work out well for you.

out1a----com1----> out1b
out2a----com2---> out2b

of course if it is a brushless motor this will not work. i doubt it is brushless with internal reduction.