Was wondering if any of you have used a step up transformer to regulate/stabilize voltage—-my problem is that on the upper helm my current fluctuates considerably so much so that a frig with low voltage protection keeps switching off. The fluctuation is less than one volt..nothing else seems to care but the frig does. The transformer would take input from 11-13 volts and output a steady 12 volts. Wonder if anyone has tried this. Thanks
Step up transformer
- Thread starter cbouch
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tiltrider1
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I thINK your real problem is undersized wire. Running a larger gauge wire would most likely solve your problem. Since the issue is only the flybridge I’m guessing you are suffering from voltage drop due to an overly long run of a too small gauge wire.
STB
Guru
Edit: TL;DR: You may want to see if you can adjust you refridge's low voltage setting and/or clean up wiring before adding a conditioner to the voltage and the conditioner you are thinking of is likely a device known as a "DC Boost converter", a "DC Step Up Converter", a "DC Boost Buck Converter" or an "Adjustable DC Converter". A transformer is for AC, not DC.
Transformers are usually for AC current. 12v on boats is usually DC current. I think the device you are thinking of is called a "DC Boost Converter", "DC Boost Buck Converter" or "DC Step Up Converter".
Transformers use electromagnetic coupling, i.e. induction, across two coils to adjust the voltage. Transformers scale one voltage to another voltage by a fixed ratio, i.e. the number of turns in one of the coil to the number of turns in the other coil. But, they do not stabilize it. If there is fluctuation at the input end of a transformer, there will be the same fluctuation, as a percentage, on the output side of a transformer. And, because transformers rely on flux, a property of AC current, they won't work for DC current. Commonly available units also tend to make big changes, e.g. 2:1 or 1:2, not 1:1.108.
A DC boost converter is a form of switching power supply that can both increase and stabilize a DC voltage. A DC buck converter lowers and stabilizes DC voltages. A "DC Boost Buck Converter" can take a range of DC inputs, a little above to a little below the desired voltage, and produce a reasonably steady DC output, e.g. 9-18vdc input is rendered to 12vdc +/1 0.1vdc output. Boost-Buck converters basically work by internally switching on-and-off really quickly to approximate an AC signal and the feeding that to an inductor that produces output at about the right output voltage, and then conditioning that output further, often times with capacitors to smooth out ripple.
I've used boost-buck converters to stabilize voltage for very sensitive DC devices -- but never on a boat. On boats I've used boost converters to run 24v devices from 12v boats, and buck converters to do the opposite.
In theory, one of these devices could be used to resolve the problem you've got. And, there are plenty for sale on Amazon and elsewhere, many fully waterproof. They tend to be somewhat inexpensive, even for reasonable wattages.
...Feel free to search amazon or elsewhere for a "12v dc boost converter" or "12v dc step up converter" or "adjustable DC step-up converter" of an appropriate wattage and input range.
But, I wouldn't jump to one as a solution. It might only be a band aid for a problem that could make itself worse in other ways. Or, even easier it' may be a fix for a non-problem: The refrige may just needs a setting change.
What is the cause of the voltage fluctuation? How much is the voltage fluctuation? And, what specifically is your goal with respect to how low you want to go?
If you are trying to squeeze out a little more runtime from the fridge as the voltage from the batteries slowly gets lower from use, it is probably unnecessary to use a converter. Most popular refrigerators allow you to change this voltage cut-off, either via soft-settings or by changing a physical setting on the converter. My refrigerator and freezer both use a controller that let's one change this setting changing the value of a cheap common resistor:
-- https://www.secop.com/fileadmin/use...c_unit_ac-dc_101n0510_08-2019_desi101g202.pdf
If you've got a lot of resistance going from your batteries up to your devices such that, even when your batteries are fully charged or your alternator or charger are putting out good voltage, it is low by the time it gets to the device, you probably want to clean up all of the connections in-between so that they aren't high resistance.
If the voltage suddenly drops when some device is active, you probably want to check to see if that device is working normally, if there is a connectivity problem, and/or if your batteries and supplies are operating normally.
I wouldn't use a boost-buck converter instead of adjusting a setting on the refrige.
And, I wouldn't use one instead of cleaning up a wiring problem.
But, I guess I might use one to fix a really sensitive device that wouldn't allow for calibration and was otherwise operating normally.
Transformers are usually for AC current. 12v on boats is usually DC current. I think the device you are thinking of is called a "DC Boost Converter", "DC Boost Buck Converter" or "DC Step Up Converter".
Transformers use electromagnetic coupling, i.e. induction, across two coils to adjust the voltage. Transformers scale one voltage to another voltage by a fixed ratio, i.e. the number of turns in one of the coil to the number of turns in the other coil. But, they do not stabilize it. If there is fluctuation at the input end of a transformer, there will be the same fluctuation, as a percentage, on the output side of a transformer. And, because transformers rely on flux, a property of AC current, they won't work for DC current. Commonly available units also tend to make big changes, e.g. 2:1 or 1:2, not 1:1.108.
A DC boost converter is a form of switching power supply that can both increase and stabilize a DC voltage. A DC buck converter lowers and stabilizes DC voltages. A "DC Boost Buck Converter" can take a range of DC inputs, a little above to a little below the desired voltage, and produce a reasonably steady DC output, e.g. 9-18vdc input is rendered to 12vdc +/1 0.1vdc output. Boost-Buck converters basically work by internally switching on-and-off really quickly to approximate an AC signal and the feeding that to an inductor that produces output at about the right output voltage, and then conditioning that output further, often times with capacitors to smooth out ripple.
I've used boost-buck converters to stabilize voltage for very sensitive DC devices -- but never on a boat. On boats I've used boost converters to run 24v devices from 12v boats, and buck converters to do the opposite.
In theory, one of these devices could be used to resolve the problem you've got. And, there are plenty for sale on Amazon and elsewhere, many fully waterproof. They tend to be somewhat inexpensive, even for reasonable wattages.
...Feel free to search amazon or elsewhere for a "12v dc boost converter" or "12v dc step up converter" or "adjustable DC step-up converter" of an appropriate wattage and input range.
But, I wouldn't jump to one as a solution. It might only be a band aid for a problem that could make itself worse in other ways. Or, even easier it' may be a fix for a non-problem: The refrige may just needs a setting change.
What is the cause of the voltage fluctuation? How much is the voltage fluctuation? And, what specifically is your goal with respect to how low you want to go?
If you are trying to squeeze out a little more runtime from the fridge as the voltage from the batteries slowly gets lower from use, it is probably unnecessary to use a converter. Most popular refrigerators allow you to change this voltage cut-off, either via soft-settings or by changing a physical setting on the converter. My refrigerator and freezer both use a controller that let's one change this setting changing the value of a cheap common resistor:
-- https://www.secop.com/fileadmin/use...c_unit_ac-dc_101n0510_08-2019_desi101g202.pdf
If you've got a lot of resistance going from your batteries up to your devices such that, even when your batteries are fully charged or your alternator or charger are putting out good voltage, it is low by the time it gets to the device, you probably want to clean up all of the connections in-between so that they aren't high resistance.
If the voltage suddenly drops when some device is active, you probably want to check to see if that device is working normally, if there is a connectivity problem, and/or if your batteries and supplies are operating normally.
I wouldn't use a boost-buck converter instead of adjusting a setting on the refrige.
And, I wouldn't use one instead of cleaning up a wiring problem.
But, I guess I might use one to fix a really sensitive device that wouldn't allow for calibration and was otherwise operating normally.
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Ok...you are 100% correct...I was referring to the devices you describe. The frig that I have seems to be very intolerant of what I would view as minor flucation..I think I will clean up the connections and see what happens..might also run a heavier wire..thanks very much..
STB
Guru
What make and model of fridge is it?
A regulated power supply will output stable voltage, but I’ve never needed one for a refrigerator. If you do decide to go that route after checking all the wire, be sure to oversized it. Depending on the compressor/controller is set up, starting current may be pretty high.
Actually it is a portable fridge/freezer made by VEVOR Model C15 Like many units like this it has a built in smarts that keeps you from killing your battery if running off a rv or vehicle. I have found this function to be very sensitive in that it goes into error mode very easily due to again minor fluctuation of voltage.
STB
Guru
You should be able to drop that protection all the way down to 9.6v. That's what's on their Web page and in the manuals for a bunch of other coolers thst seem.to use the same controller.
Check out the manual or one with a similar control panel. For whatever reason, I can't confidently find the right manual on the Web.
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that's a nice little portable fridge if it works well. i didn't know they were so inexpensive. stb has got you on the right track, i've seen adjustable low voltage cutout circuits on similar controllers.
STB
Guru
I've got a similar Alpicool unit from Amazon. Had it for years on my flybridge only under the cover cover the bimini top. Runs 24x7. It's been up there through everything, even nearby hurricanes. Love it.
crazy. i saw they have bigger ones with two compartments, each with it's own temperature control. also listed as frost free. i can see getting one for overflow fridge space on long trips.
i appreciate your input to the OP on this thread.
STB
Guru
crazy. i saw they have bigger ones with two compartments, each with it's own temperature control. also listed as frost free. i can see getting one for overflow fridge space on long trips.
i appreciate your input to the OP on this thread.
This is the one I have...3 years old now:
Alpicool*APLT60-LG*Dual*Temperature*Control*12*Volt*Refrigerator*Portable*Car*Fridge*Freezer*63*Quart（-4°F~68°F） for*Truck,RV,Boat,Camping*and*Travel https://a.co/d/bV8WNlc
I also have the cover. I'm on my 2nd one. They seem to be good for 18months in the sun -- about the same as my furniture covers. The zipper seems to keep the top locked down even in super high winds. I have the cooler tied down, but let the zipped cover keep the top closed in storms vs straps.
T60 Insulated Protective Cover Insulated Transit Bag for Alpicool T60, Bodega 64 Quart, VEVOR 63 Qt Dual Zone Car Fridge Freezer https://a.co/d/d5BBeKe
Only problem I had is that the LED faded in brightness, but they sent me a new one free -- even years out of warranty. I just messaged them pn Amazon and had it 2-3 days later.
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For 150.00 seems hard to beat. I used it with the provided 110 ac power supply for most of last summer... maintains ice cream beautifully...it’s intent though is for ice on the upper helm. I have enough ideas to resolve the problem and look forward to working on it in the spring..
