Getting 36v from a 12v battery

Hi people,
The plot thickens on the gate opener. I have tracked down a manual for
the satellite actuator and it is 36v. So now we are talking opening
speed.
Problem is how do I get 36vdc at around 4A out of a 12v battery? I
have to solar charge the battery.
One thought is to use 3 smaller 12v batteries in series each with
their own dashboard-style solar charger. Those dashboard chargers are
rated at 5W and they have a non-discharge diode which would prevent
back flow into the panel. Would that work????
Any thoughts on this or other alternatives? A dc-dc converter would be
costly for 36v @ 4A continuous I am guessing.
I did a surplus search and found one 12v-36v converter for $125, way
outta my league for this project. Admittedly it was rated at about 30A
or more.
Reply to
Jenny3kids
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Should work, getting kinda spendy for a workaround. I'd test it with 3 batteries in series to see if it does what you want it to before I went to the trouble of setting up the charging circuits.
As far as that is concerned, we used to run outboards with electric start and no charger for months. Just have to recharge occasionally.
snipped-for-privacy@msn.net wrote:
Reply to
RoyJ
One idea that might use only a handful of relays to do what you want.
How about if you switch the batteries into parallel for charging, and kick them over to series when the actuator is running?
'Bout the only caution I can forsee is make SURE you have "break-before-make" relays! (most are)
LLoyd
Reply to
Lloyd E. Sponenburgh
"Lloyd E. Sponenburgh" wrote: (clip) How about if you switch the batteries into parallel for charging, and kick them over to series when the actuator is running? (clip) ^^^^^^^^^^^^^^^^^^^ That would work, but you would be dividing the charging capacity of your charger among the three batteries. Isn't it simpler just to do it the way you first described--use one charger for each battery? Chances are it would be just as cheap, because I expect that one big charger would cost about the same as three smaller ones.
Reply to
Leo Lichtman
Yup. 3 garden tractor batteries and 3 solar chargers. But are you sure the satelite actuator has enough power to open the gate? 36 volts X 4 amps = 144 watts. That's only about 0.2 Hp at 100% efficiency and you'll be lucky to get 80% of that to the load, I'd guess.
Pete Stanaitis ---------------------------
snipped-for-privacy@msn.net wrote:
Reply to
spaco
Better than my idea, which was to charge the batteries one at a time, switching to the next battery in the bank each time the gate is operated. But that requires a stepping relay or the like, instead of a couple cheap cube relays.
Ned Simmons
Reply to
Ned Simmons
The C-band dish actuators (or jacks) that I've seen generally have load ranges of up to 400 or 600 pounds, with working strokes up to about 18" IIRC.
The permanent magnet motors are typically about the same physical size as an automotive windshield wiper motor, that uses gear reduction (parallel, not worm) to attain higher output torque. The output shaft of the motor gearbox is coupled to a ballscrew to attain high linear thrust.
The actuator section is fairly heavy duty, although the gearbox reduction gears are generally plastic/synthetic.
WB metalworking projects
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Reply to
Wild Bill
You might want to locate a 24V motor/gearbox, which I think are fairly common. The 24V motor will run a little faster at 12V, than the 36V motor will. If the motor were 12V, it would probably simplify the application.
Another option might be to gut/modify the existing motor case, and use the existing armature shaft as a driven arbor, driven by a belt and a 12V motor. The existing motor's shaft will likely have gear teeth machined into the end, so it would need to be utilized as an input shaft for the other drive motor.
WB metalworking projects
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Reply to
Wild Bill
snipped-for-privacy@msn.net wrote in news:rl6l035d899l94q9idvl8gcsaq7oii834v@ 4ax.com:
3 deep cycle batteries and the charger(s). If the gate is used often, I would go with 3 chargers, if not, one and switching to charge all 3 batteries in parallel as Lloyd suggested.
Reply to
Anthony
How about just buying a 12 volt actuator? They are readily available. If you want to speed up the gate just install a simple fulcrum lever in the system OR shorten the current lever. No real sense in going overboard. Heck if you want a lot of fun rig it up with a couple air rams and a small compressor charging a tank. Crank the PSI up and you could snap the gates shut like a trap.
Reply to
Steve W.
Hi Bill,
This has a stroke of 15" and a caution in the manual of "force up to 1000lbs." Now THAT's a gate opener. LOL
Reply to
Jenny3kids
As Bill explained the mechanism Spaco. I am sure there is more than enough grunt available. Thanks for the comment though.
Reply to
Jenny3kids
Hi Roy,
I have tested it today with a variable PS and works fine. Now all I need is the 36v side sorted out. Given that this version will not have the inverter running all the time, I might just try the charge the 3 batteries once a month idea.
Reply to
Jenny3kids
Hi Steve,
Ahhh, missing the point here Steve. It's about using what you got. This has become a challenge. As Don said about his boat lift in the other thread.
Reply to
Jenny3kids
You may be correct, but I will make that my fall back if I have to. I have found some surplus 24V converters for around 20-bucks. Still hopeful for a 36v. May use the 24v and see how it works. It will be twice as fast as it was.
Reply to
Jenny3kids
Good thought Lloyd, I will give it some more thought. Sounds the best idea so far if I can't find any reasonably priced converters.
Reply to
Jenny3kids

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