Speed up gate opener suggestions

Hi Rick,

actuator to

Interesting thought. As you imply, it doesn't matter if it takes 2 minutes to close it, providing it opens quickly. Great thought.

Reply to
Jenny3kids
Loading thread data ...

Hi Gunner,

Love your tag lines.

...but wouldn't a bank be in 12v parallel? What would they use 36v for in an RV? I've never owned or even been in one so really don't know.

Reply to
Jenny3kids

I don't doubt that I'm wrong, but I don't understand WHY I'm wrong. Can you explain the error in my logic so that an electrically challenged individual can understand?

Reply to
Dave Lyon

Actually, I'm wrong, too. The diode array works only with an AC charging source, supplying the "parallel" branches through capacitor coupling. It won't work with DC.

The reason you cannot use just "a second set of wires" without some active switching (like relays) is that the second set of wires provides a permanent short-circuit across the high-voltage series connections.

LLoyd

Reply to
Lloyd E. Sponenburgh

to

Gravity can be your friend..maybe some tapered collars on the hinges (similar to self closing doors). It would raise the gates up a little in the closed position though.

Then there's that momentum thing once they get goin'...

Reply to
Rick

Hi Rick,

Thanks but we get winds gusting to 50mph about 1/3rd of the year. Gravity would come off second best to that. Nope, the close and open need serious grunt. Next really windy day I will take a spring scale down and see if I can measure the closing force needed. Might scare me. Sometimes it is all I can do to close it and that's 13' from the hinge. The closer is going to be 3' on a 13' gate. I am guessing around 400lbs at the closer mount point.

Reply to
Jenny3kids

You can do it with one spst switch and a few diodes.

Reply to
clare at snyder.on.ca

You need the diodes to direct the current where you want it. Relays would do it, but would need to be switched into the circuit when you wanted to switch from the parallel charging circuit to the series motor circuit.

The diodes would automatically prevent the DC from going the wrong way.

I have used diodes to charge batteries in a trailer off of the tail light circuit. If the diode wasn't there, the trailer battery would light the tail lights.

Ron Thompson On the Beautiful Florida Space Coast, right beside the Kennedy Space Center, USA

formatting link
My hobby pages are here:
formatting link
Visit the castinghobby FAQ:
formatting link
The member map is here:
formatting link

Reply to
Ron Thompson

I don't think you are wrong. Diodes block DC in one direction and let it pass in the other.

You would need one diode between each battery in the series circuit that would handle the motor current, and six diodes that could be smaller between the charger and the individual batteries.

Ron Thompson On the Beautiful Florida Space Coast, right beside the Kennedy Space Center, USA

formatting link
My hobby pages are here:
formatting link
Visit the castinghobby FAQ:
formatting link
The member map is here:
formatting link

Reply to
Ron Thompson

That's the logic. But if you work out the array, you'll find that the necessary diodes for the "parallel" arrangement provide false paths across the series array. Three caps and an AC charging supply solve that. But that's not what Jenny has as a source -- she'd have to build an inverter to get the AC.

LLoyd

Reply to
Lloyd E. Sponenburgh

Hi Ron,

I was wondering about that yesterday when I did a schematic. I was unsure if you can use a diode on the negative leg of the solar panel though. Care to post a schematic of the suggestion? I may be able to use the solar panel I have now if that will work.

Reply to
Jenny3kids

Er, Clare,

Wouldn't that mean that I would have to switch in/out the charging circuit twice daily?? I might as well open the bloody gate.

Are you an academic and/or teacher? Hate to say it but all your suggestions on this topic so far have all lacked real world practicality.

Reply to
Jenny3kids

Certainly not an accademic, (although I have been a technical teacher) but I built an electric car using this very setup. The batteries charged in parallel (as a 24 volt pack) and ran in either parallel or series (24 or 48) depending on how fast I wanted to go. A single relay controlled the series parallel switching, with 2 diodes. For your application, the remote control would operate a DPST relay which would switch the batteries to series and turn on the motor. When the gate opened to the limit switch, the leads to the motor would be reversed, so the next time the remote was triggered, the gate would close. Any time the motor was not running, the relay would be de-energized, and the batteries would be back in parallel for charging. Perhaps not the simplest setup - but definitely doable, and a low-buck solution. Using diodes only will not work. Using relays only is complex and trouble prone.

And what is impractical about a 36 volt system that uses a 36 volt charging array to charge a 36 volt battery pack? It's done ALL THE TIME in industrial applications. (Which was, I believe, my last recommendation)

Reply to
clare at snyder.on.ca

OK, maybe I am wrong. Here is a hastily scrawled schematic:

or

formatting link
Sorry, I couldn't remember the correct orientation of the diode symbol, so I used arrows to indicate current path. Wouldn't this work? I don't see the false paths you spoke of.

Ron Thompson On the Beautiful Florida Space Coast, right beside the Kennedy Space Center, USA

formatting link
My hobby pages are here:
formatting link
Visit the castinghobby FAQ:
formatting link
The member map is here:
formatting link

Reply to
Ron Thompson

Number your diodes according to height in your drawing, starting with D1 at the bottom.

The solar panel sees a short path thru D2, D3, D4 and thru D5,D6,D7.

Reply to
Don Foreman

DOH! I feel like Homer Simpson! Thanks for pointing this obvious flaw to me.

How about a small relay to fix this that would energize with the switch to open the gate? The relay would be normally open at diodes 3 and 6 and normally closed at all others. Of course then diodes 3 and 6 would not be needed. All other diodes would separate the batteries for charging.

Ron Thompson On the Beautiful Florida Space Coast, right beside the Kennedy Space Center, USA

formatting link
My hobby pages are here:
formatting link
Visit the castinghobby FAQ:
formatting link
The member map is here:
formatting link

Reply to
Ron Thompson

That could work. You could put NC contacts in place of D4 and D7, NO contacts as you describe, keep D2, D5 and D8 as is and omit D1. Maybe that's what you meant. A DPDT relay would suffice.

Essentially you'd be switching the negative terminals of the top two batteries from one configuration to the other, while D2, D5 and D8 serve to allow charge current to flow to each battery but prevent current flowing from + of one battery to + of another. In this situation, the lowest battery will get most of the charge current until it's voltage is about the same as the next lowest, and so on. Eventually they would all be equalized at the same state of charge and voltage.

Reply to
Don Foreman

It's too hard to figure who said what with the "quote" bars BUT the battery symbol is wrong. The long line is the +. ...lew...

Reply to
Lew Hartswick

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.