"Tricking" a 0-5 V hall effect throttle?
Hi,
I've got a Kelly KDS48100 and I need to limit the current to protect my motor. Allegedly it is programmable but I've had no luck programming it. It'll say "sure, current limited to x%" but then not limit current at all. Kelly's help support is abysmal.
Is there a way to "trick" the controller into thinking that I am only going to 25% throttle when I am going to full throttle? It would be a piece of cake if I had a 0-5k Ohm throttle. I have no clue how the Hall Effect works. I tried putting a potentiometer in series with it (0-5k or 0-100k) and got weird results. Either no difference or at some point the controller would take off while i had zero throttle.
Anyone overcome this particular hurdle before?
You need to reduce, or divide, the VOLTAGE output of your throttle, without damaging it. Placing a low voltage zener diode in parallel with its 0 to 5 volt output MIGHT work, but if no provision for current limiting is provided, either the zener diode or the throttle may have their current ratings exceeded at full throttle. A better solution would be to install a voltage divider, perhaps using 2 resistors, such as two 1/4 watt @ 1,000 ohms, across the 0-5 volt output, and connect the controller to the midpoint of the resistors. This will now give 0-2.5 volts maximum, and changing the ratio of these resistors will cangce the voltage division ratio. If the total resistance is kept at 2,000 ohms, the resistor current will be limited to 2.5 milliamperes maximum, at full throttle. An added advantage of this voltage divider over the zener diode, is the fact that the operating range/physical funcionality of the throttle control remains the same, so you still turn it just as far, to reach the new, lower top speed as previously required to go faster.-Bob
Hi Bob,
I think that is exactly what I need, a way to limit the output to the control, but still give me sensitivity of full throttle.
Only thing is, I have no idea how to wire a voltage divider. Is it easy? Is it split, one side goes resistor then to ground, the other side is a resistor to the throttle?
thanks,
Todd
Do you know of the color code on your Hall effect?
On the XM-3000 there is a switch on it to limit speed but on the XM-3100 they got rid of the switch.
I forgot how to insert quotes so I used quotation marks.
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< "I've got a Kelly KDS48100 and I need to limit the current to protect my motor. Allegedly it is programmable but I've had no luck programming it. It'll say "sure, current limited to x%" but then not limit current at all. Kelly's help support is abysmal.
Is there a way to "trick" the controller into thinking that I am only going to 25% throttle when I am going to full throttle? It would be a piece of cake if I had a 0-5k Ohm throttle. I have no clue how the Hall Effect works." >
This is a homebuilt project, here is all the info I have on the throttle:
http://www.newkellycontroller.com/product_info.php?cPath=36&products_id=488
Ok, sorta new questions. Volts are volts right? My controller says it wants 0-5V. I measure it using the hall effect throttle and it appears to be so. But if I put a 0-5k ohm pot in the loop instead of the throttle, I can control volts in the 0 to 5 range, but I get no output from the controller? What gives.
I'm at the end of my rope. I think this was a $139 lesson: never use some mystical magic "hall effect" that you don't understand, and never buy a Kelly controller, their customer support is crap and their "programmable" controllers don't respond to programming.
Give me a telephone call, or send me YOUR number, I will try to talk you through this!---Bob Curry, 301-439-3873 (Maryland, USA)
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you could wire a 3.3v zener diode in parrallel with the throttle,
that should hold the max throttle output down to 3.3v.
what throttle setting this corresponds to will depend on what the lower and upper limit settings are in the controller.
Matt