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Re: Speed Controller Design
OK,
Time for a little better definition here. The Jaguar and the Victor differ a little in the method of motor control but not much. The H bridge is basically the same for both, four sets of FETs. To drive in one direction a FET must be connected to the high side and another to the low side. In your drawing above, the diagonally connected FETs are turned on for this mode. Q1 and Q4 for one direction and Q2 and Q3 for the other direction. (Observe current flow through the motor when visualizing these modes.)
Where the Jaguar and Victor differ is that in the Victor, both FETs in the pair are controlled by PWM signals while in the Jaguar, only the high side FET is PWM while the low side FET is ON for direction.
The Brake Mode jumper operates in a similar manner for both types. The Brake Mode will turn on both low side FET pairs in a zero throttle condition while the Coast mode will turn off all FETs. Note that during Brake Mode, current supplied by the motor is shunted through one pair, the common power supply lead and then through the other pair. During Coast, no current flows.
The locked anti-phase that Eric refers to is a condition where the controller is supplying a 50% duty cycle of forward and reverse commands essentially locking the motor shaft in position under power. Please note that this could be a relatively large current demand as current is flowing in the motor all the time. Gary, correct me if I am wrong, but I was under the impression that both the Tan and Black Jaguars could only provide lock mode (analog control mode) under CAN control with encoder input provided at the controller or through the buss. The difference between the two is essentially the RS232 input and the change in the FETs to provide 24 volt input on the Black.
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Good Luck All. Learn something new, everyday!
Al
WB9UVJ
www.wildstang.org
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Storming the Tower since 1996.
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