While I love the simplicity of your approach, it seems to have a HUGE down-side of not using the batteries uniformly. The lowest battery is drained most, followed by the next highest, etc...
If you had relays that would reconfigure the batteries to swap the series connections to parallel connections - then you could at least use all the batteries. But then, you're adding a lot of expensive high power relays, and the risk of something getting crossed up...
Same is true of swapping the batteries - if you could easily rewire which battery was lowest in the chain on each trip, that would be nice. I just can't think of an easy way to do that without (again) a lot of relays (digital or mechanical).
John
From: "Bill and Ai Qiu hopen billhopen@yahoo.com [electricboats]" <electricboats@yahoogroups.com>
To: electricboats@yahoogroups.com
Sent: Friday, August 28, 2015 9:44 AM
Subject: Re: [Electric Boats] Re: Throttle lever potentiometer, any suggestions?
Hilsen fra USA Bendik,
I have dispensed entirely with "controllers", the most expensive and breakable weak link in the drive chain. (they blow up just when you need them the most, under extreme power shifting) I don't know what motor you have, but most permanent magnet DC motors can be reversed with a 3-position (Forward-off-Reverse) heavy duty reversing DPDT switch available for about $12-15 USD, on ebay. next, for speed control, make up a simple battery array, hooking your cells in series to be at maximum voltage to run your motor. (mine is a 36v motor that i run at up to 48v) I then run 4 leads from the ground terminal at 12v,24v,36v,48, steps. these leads terminate at 4 copper buttons on a piece of wood or plastic
By building a simple HD slide switch with a copper power bar pivoting between any of the 4 button terminals , I select the voltage I wish to run at. Its simple, safe and bullet proof. I find that very slow speeds are used very little, just for docking and manuvering, and I rarely use the highest power which is fighting to climb the hull speed limit wave......95% of my use is at the battery conserving speed, or the moderately efficient cruising speed. I always start low V slow, and "shift" up through voltage as my sailboat gains momentum, I have a very large 18" bronze prop with high surface area, that traction would lurch the boat and strain the motor brushes and possibly arc the reversing switch if I just threw it on at a stand still into 48v.
If I bought a HD controller, it would cost more than my motor, more than my 4 batteries, and it would be the first thing to malfunction. Perhaps if I could find a good used controller salvaged from a golf cart I would be tempted to run 48v full time through a Mofsat array. But I love the simplicity of this home-made variable voltage rig. The downside is efficiency loss at low voltage speeds and possible overheating in over volting speed. I am putting in a fan air cooler and have a thermo-sensor at the motor.
Skol
Bill Hopen - www.billhopen.com
Hopen Studio Inc - 227 Main St., Sutton WV 26601
304 -765-5611 billhopen@yahoo.com
Hopen Studio Inc - 227 Main St., Sutton WV 26601
304 -765-5611 billhopen@yahoo.com
From: "Bendik Vignes bendik.vignes@yahoo.com [electricboats]" <electricboats@yahoogroups.com>
To: electricboats@yahoogroups.com
Sent: Wednesday, August 19, 2015 7:33 AM
Subject: [Electric Boats] Re: Throttle lever potentiometer, any suggestions?
Thanks for your reply Dominic!
I am not very familiar with the physics of hall effect sensors, but they
produce a voltage signal, right? My siemens inverter is controlled with a
potentiometer, and I believe I can not use a hall effekt sensor..(?)
Regards Bendik
Den tirsdag 18. august 2015 skrev Dominic Amann dominic.amann@gmail.com
[electricboats] <electricboats@yahoogroups.com> følgende:
>
>
> My solution is a Hall effect sensor - a small rare-earth magnet mounted on
> the lever, and the sensor embedded in the bulkhead, so that the transit of
> the lever varies the hall-effect resistance. No rubbing parts = 0
> maintenance.
>
I am not very familiar with the physics of hall effect sensors, but they
produce a voltage signal, right? My siemens inverter is controlled with a
potentiometer, and I believe I can not use a hall effekt sensor..(?)
Regards Bendik
Den tirsdag 18. august 2015 skrev Dominic Amann dominic.amann@gmail.com
[electricboats] <electricboats@yahoogroups.com> følgende:
>
>
> My solution is a Hall effect sensor - a small rare-earth magnet mounted on
> the lever, and the sensor embedded in the bulkhead, so that the transit of
> the lever varies the hall-effect resistance. No rubbing parts = 0
> maintenance.
>
On Sunday, August 16, 2015 11:21 PM, Bendik Vignes <bendik.vignes@yahoo.com> wrote:
Hi! Has anyone a suggestion for an affordable solution for a thottle lever potentiometer? I am open to diy solutions as well... The motor inverter I will be using has speed controll with a potentiometer (0-5kohms I believe), and direction change is controlled by switching ground to forward or revers terminals on the inverter (sorry for the bad explanation). Preferably I would like throttle and direction change in one lever... Regards |
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Posted by: oak <oak_box@yahoo.com>
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