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Solar system design? Answered

I have a solar powered gate, using a liftmaster system. The main control box cannot have a power input above 12 dc at 30 watts. I need to be able to control the power input to about 25 watts. Due to the environment in which the system was installed, I had to use solar panels and batteries that have a higher output than 30 watts.
How can I do so? I tried to google adjustable amp regulators, and the answers are not clear. How can I find an adjustable amp regulator for my specific needs?



6 weeks ago

Seems a little confusing. Lets say you have an outlet in your house and the circuit breaker is 20 amps. If you plug in a clock that takes and amp there aren't limiters to cut it down to an amp. Covert amps to watts and the example becomes a 2400 watt circuit breaker and a 120 watt clock.
Generally, Your looking for a system with at LEAST 25 watts or MORE. Any startup of the liftmaster may actually pull a few more watts when it starts, so having a few more is a good thing, since the liftmaster doesn't pull more and kill a fuse or kill the system. People that do solar look to expand all the time, so they will get a bit more in watts for what they can afford to cover any additional watts that they didn't think of, like a corded drill, or a light.
If I understand this your hooking power to the liftmaster system. So hopefully the system has a regulated supply, which is going to take the solar supply and regulated the voltage and 'amperage' or watts it needs. If you need a 12 volt regulated supply, those are sold premade as 12 volts and whatever amps. If your question is go regulate amps for some reason by building it, your into designing a regulated power supply. Hopefully the above options answers your question. RJF


Answer 6 weeks ago

I didn't quite follow your answer. I was a bit more clear in another question I asked else where, so I will post it here.
My family's gate is controlled by a solar system designed by liftmaster, LA412. Due to the large number of trees we have, my dad did not use the solar panel that came with the system. It came with a 12 volt 10 watt solar panel. Instead, he used a 100 watt 12 volt solar panel, and he used a bigger and different solar use battery, outside of the liftmaster control box. The manual for the liftmaster controller said it can take up to 12 volts 30 watt max. So my dad cut into the 2 wires feeding the power side of the board ( i think ) , and then connected his power wires from his external battery (that is charged by the 100 watt solar panel ) to those 2 wires.
Now the led on the liftmaster control board for 'low battery' stays on, and he thinks the internal 12 volt 33 ah battery is not charging. He thinks he shouldn't need it, since the battery feeding the power side of the control board is full of power.
He has offered to pay me $50 if I can figure out how to limit the amps coming from his external battery ( Concorde 12V 108ah AGM Battery ) , so that it can be hooked up to the solar wires for the control board, as opposed to the battery wires for the control board.
I have been very interested in electronics since I was at least 5. I love taking electronics apart, and drawing pictures of the circuits. There is so much detail. But I can not figure out the best way to limit the amps to under 30 watts?.... I am not sure how watts translate to amps. And then there is the 'open circuit' and 'short circuit' ratings...... Is there such a thing as an amperage regulator, that will maintain the needed 12 volts, but limit the amps to under 30 watts? How would I find an amperage regulator?