| Author |
Message |
Shawn Hollingworth
Unregistered guest
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| Posted on Saturday, July 15, 2006 - 10:31 am: |
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Hi, is there any way I can run the 4qd vtx 12v 75a speed controller off a 7.2v battery? thanks shawn. |
Admin (Admin)
Board Administrator
Username: Admin
Post Number: 239
Registered: 10-2004
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| Posted on Saturday, July 15, 2006 - 6:29 pm: |
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Shawn,
No there isn't as this voltage is too low to energise the on-board reversing relays (which need some 9.5V minimum) or to power on the on-board 9.1V constant supply (which needs over 10V). |
james (Jaybee)
Member
Username: Jaybee
Post Number: 6
Registered: 3-2009
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| Posted on Tuesday, March 31, 2009 - 10:00 pm: |
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HI i though i would post this time in the correct section.
I am using two MY1018E motors (24v 300w) can you recommend the correct tacho feedback motor to use with this please.
The controller will be the VTX75.
Thanks. |
Admin (Admin)
Board Administrator
Username: Admin
Post Number: 1024
Registered: 10-2004
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| Posted on Wednesday, April 1, 2009 - 7:21 pm: |
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James,
If you do a search on Quadra 'Names of Authors' you will find a number of posts about feedback on the VTX75. The problem was that 4QD would not supply us as a dealer one off VTX controllers with the tacho feedback board fitted. The customer did manage to persuade 4QD to do it for him though. Check out those posts and any further questions let us know. |
james (Jaybee)
Member
Username: Jaybee
Post Number: 7
Registered: 3-2009
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| Posted on Wednesday, April 1, 2009 - 9:25 pm: |
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Thanks admin,
I have today talked to quadra as he is a member on the forum for the cars we are building, he reports that its working very very well and his top speed was almost 10mph,! he has also resticted the throttle pot so top speed is now around 4mph.
Thanks |
Quadra (Quadra)
Member
Username: Quadra
Post Number: 7
Registered: 1-2008
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| Posted on Wednesday, April 15, 2009 - 3:39 pm: |
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Hi Paul
I am in need of help again. So my model landrover is all running well, but in my quest to improve it, I need a bit of electrical knowledge. The throttle pot I use is a 5k one (part number 2000-300). I have mechanically restricted the movement so that it only gives 3.6k at restricted throttle pedal deflection, this limits the top speed of the car to about 4 mph. The only issue is that there is very little travel on the pedal, which got me thinking. Is it possible to make the throttle pot only give 3.6k or there abouts, rather than 5k at full travel. Could I build a little circuit which would do this, or use some resistors to give less ohmage at full deflection. Ideally, I would like to be able to flick a switch which would either limit the top speed to 4mph (3.6k ohms)for when my boys drive it, or not restrict it at all giving full power(5k ohms)for when I drive it. Basically I want to know if it possible to limit the top speed electronically via the throttle pot but still retain full pedal travel of the the throttle pedal, rather than doing it mechanically.
Thanks in advance Mike |
Admin (Admin)
Board Administrator
Username: Admin
Post Number: 1038
Registered: 10-2004
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| Posted on Monday, April 20, 2009 - 10:08 pm: |
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Mike,
The 4QD controllers actually look for a voltage input (voltage follower), the potentiometer is really acting as a potential divider circuit. The controllers have a gain input which can be used to limit the controller output to the motors and still provide full input pot range.
The speed controller outputs 9.1V for the input potentiometer. By using a series resistor to the top of the potentiometer (which you could short out with a switch when you need max speed), you can limit speed without limiting travel. That should work although I have not tried it. Start with say a 2k7 resistor and see how it goes.
Regards
Paul |
james (Jaybee)
Member
Username: Jaybee
Post Number: 10
Registered: 3-2009
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| Posted on Thursday, July 30, 2009 - 8:30 pm: |
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Hi can you tell me if the VTX-40 24V will be big enough to power 2 24v 300w 16A motors.
Thanks |
Admin (Admin)
Board Administrator
Username: Admin
Post Number: 1096
Registered: 10-2004
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| Posted on Saturday, August 1, 2009 - 1:51 pm: |
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James, depends on your application. The current figure of 32A is nominal at the motors peak efficiency. The motors may wish to draw more current when starting / accelerating which may be outside of the intended operating conditions of the controller. |
Ben Abraham (Ben)
Member
Username: Ben
Post Number: 1
Registered: 4-2010
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| Posted on Wednesday, April 21, 2010 - 8:32 pm: |
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Hello i need some help with VTX-40 24V, it came as open box and i want to where i could get some wiring accersories for this and how to wire it the motor and battery. Please help me...
thanks |
Admin (Admin)
Board Administrator
Username: Admin
Post Number: 1241
Registered: 10-2004
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| Posted on Friday, April 23, 2010 - 5:34 pm: |
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Ben,
Did you purchase the VTX from us? If so it would have been supplied with an instruction booklet which can also be downloaded from our website. The booklet describes in detail how to wire the supply and motor. We also stock various accessories that are suitable for 4QD controllers, what do you need in particular? |
