CountryByNet.com Forums :: Low voltage power for gate

Whoa, Joe... We need a little more detail. How much power do you need?

Gate uses how much current (how many amps) at 18 VAC?
Camera uses how much current at 13 VDC?
Intercom uses how much current at 16 VDC?

How many gate operations do you want to engineer for per day? How many of those are at night? Look up your insolation (not insulation). What is your latitude?

What about adding another larger solar panel? How many really really dark days do you want to "survive" worst case?

There are lots of avenues to be explored. Can you contact someone more knowledgeable than a telephone customer service operator at a mail order company to get some questions answered about your equipment?

Some of the options, just a few, something to entertain your brain while you are getting some of the needed info.

The camera and intercom are probably pretty low power users, especialy if not ON all the time just, on when activated by a visitor. Anyway a decent power supply to give you 13 VDC from the 18 VAC is pretty simple. If those two 13 VDC loads are as light as I think likely they will hardly interfere with the 18 VAC supply for the gate. I assume the gate would get its 18 VAC from a solar charged battery and inverter. The 13 VDC loads would probably be just perfectly happy to run off the 12.6 volt (nominal) voltage of the solar charged battery. With a good charge going the charge controller on the solar charged battery will let the DC rise to about 14.1 or 14 .2 (still not a likely source of problems for the 13 VDC equipment.)

If the loads are a tad heavier than I thought, use a slightly larger storage battery and solar panel.

I doubt you would actually NEED #6 wire. You can run a smaller wire and power a battery charger to maintain the battery to operate the gate. I doubt you would need anything so large as a 10 amp charger. I've seen several solar powered gates and the solar panel looked like it was under a 10 amp panel size, probably something like 5-7 amps. Remember that is 5-7 amps for about 6 hours a day (depending on your local insolation value.)

If you run a wire you can charge 24 hours a day at just 1 amp of DC charging current and get more charging done than the solar panel. Anyway, lets assume you want something like a 7-8 amp charger. That requires (given an efficient modern design) about 1 amp at 120 VAC. Do you really need #6 wire to get 1 amp?

Now factoring in the Egon/Nikola Tesla concepts... you can use a pair of transformers to reduce your wire size requirements. You insert a matched pair of transformers, each with a power capability safely greater than the 120 VAC power requirement at the gate. Sticking with our 1 amp example we need transformers to handle about 150 Watts or at least one at about 150, the lother could be 125.

At the electrical source you wire in one of the transformers as a "STEP UP" transformer. Take a look at the attached drawing. Lets let X = 4. The L O N G wire has 4 times the input voltage but only 1/4th the current. Remember, wire gauge is a current carrying requirement not a voltage requirement. So yo send 480 volts out to the gate. There the other half of the dynamic duo of transformers reduces the voltage by a factor of 4, back to 120 VAC to power the charger. Current in the long wire would be about 1/4 of an amp.

A cheaper way to do it would be to send up 240 VAC from your breaker box and use a battery charger made to operate on 240 (220?) VAC. At worst you would only need one transformer then for dropping the 240 to 120 to run a plain vanilla charger. With 240 VAC current and wire size requirements are cut in half which is still a savings in wire.

If you can get some decent idea of your power requirements, we can converge more closely to an appropriate disign.

Ahh, disclaimer disclaimer any engineering suggestions, drawings, or advice are strictly for entertainment and or educational purposes and are not intended to encumber anyone (especially me!) with liabilities related to any attempt to use any of this giberish.

Pat

"I'm not from your planet, monkey boy!"

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