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Car battery, or any kind of battery... just needs to be a battery, for somewhere without outlets of any kind.
Posted : 04/05/2022 2:13 pm
I would not replace the MODX AC Adaptor (PA-150B AC adaptor) with any sort of power source, rather get a UPS and then plug the Adaptor itself in it. That would work.
Make sure you match the voltage, the minimum power, and get a decent battery capacity UPS.
Back in my home country, when power outage was frequent, we used UPS for backup power for PCs (Tower Desktops) to provide backup power before the Electricity is back. Talking about ~100$ UPS that would last between 15-30 mins max.
For longer runtime, you need to invest much more.
Unfortunately, I forgot how to calculate power consumption and runtime of batteries 🙂
Best thing to do is to show your MODX/Adaptor specs to an electrician/electrical equipment store and ask them for a UPS to run your hardware for, X hours, for example.
I am sure long runtime UPS do exist these days (for camping for example), even for homes (essential equipment. lights, etc.), but I am not sure what is their price point or how long they last on a single charge.
Example UPS:
Hope it helps to narrow your research.
UPDATE:
Found this that might be helpful (those without the solar panels are in the 200$ price range). For power consumption, I would compare the MODX (16 W) to a laptop/small TV...
Posted : 04/05/2022 2:44 pm
MODX is 12V and a car battery is 12V (nominal). The right connector with the right polarity should work and maybe put a 1.5A fuse in series. This is unregulated.
Regulated: Perhaps safer would entail less DIY and use a power inverter with alligator clips. There's more loss this way (inefficiencies due to power supply stages) - but the power would be regulated two ways. Both at the AC level and also by using your standard MODX power supply. This would entail using the car battery you listed and adding an inverter.
Unregulated: You could take 8 AA batteries and put them in series and see how long that lasts (30min-1hr I'm guessing). Again needing the proper connector with the right polarity.
I wouldn't really suggest going in unregulated, though.
Posted : 04/05/2022 2:50 pm
Topic starter
This is a spitballing. As a project for daughter at school, in a tech class. They have to rig something from home to run on battery.
Have found 12v DC speakers. And a matching convertor for them to be run off a car battery. So the project part for her will be building whatever is needed to get the MODX to run off the same (or another kind of) battery.
Jason, your idea of simply doing it with AA's is amazing. D's work, too? for a longer demo?
What about remote control car batteries? They any use or too high spec? (the inner child is always looking for an excuse to buy a couple more toys)
Posted : 05/05/2022 4:04 am
Topic starter
[quotePost id=116526]I would not replace the MODX AC Adaptor (PA-150B AC adaptor) with any sort of power source, rather get a UPS and then plug the Adaptor itself in it. That would work.
Make sure you match the voltage, the minimum power, and get a decent battery capacity UPS.
Back in my home country, when power outage was frequent, we used UPS for backup power for PCs (Tower Desktops) to provide backup power before the Electricity is back. Talking about ~100$ UPS that would last between 15-30 mins max.
For longer runtime, you need to invest much more.
Unfortunately, I forgot how to calculate power consumption and runtime of batteries 🙂
Best thing to do is to show your MODX/Adaptor specs to an electrician/electrical equipment store and ask them for a UPS to run your hardware for, X hours, for example.
I am sure long runtime UPS do exist these days (for camping for example), even for homes (essential equipment. lights, etc.), but I am not sure what is their price point or how long they last on a single charge.
Example UPS:
Hope it helps to narrow your research.
UPDATE:
Found this that might be helpful (those without the solar panels are in the 200$ price range). For power consumption, I would compare the MODX (16 W) to a laptop/small TV...
[/quotePost]
absolute gold for chilling beers in the bush, very cool!
THANK YOU!!!
Posted : 05/05/2022 4:05 am
Topic starter
[quotePost id=116531]
Anyway to run a MODX off a battery?
As others have suggested it ALL depends on what your real needs are:
1. how much power do you need? Keyboard only using headphones? Keyboard AND powered speakers?
2. how long do you need that power?
3. how much do you plan to spend?
A portable generator is a great all-around power solution for a camping/remote environment. Since it doesn't rely on batteries it can provide a LOT more power than any UPS can. And it can have regulated output, you can refuel it and no batteries that need recharged.
You can get one that puts out 240 if you need that and it can power lights and other things as well as plugging your keyboard into it.
If you are camping out in your car you can get converters as low as $30 - https://www.amazon.com/dp/B07Z4FCJJG/ref=redir_mobile_desktop?_encoding=UTF8&aaxitk=50540cdaa6d9769cdfac4e989d05f7a9&hsa_cr_id=9898598060901&pd_rd_plhdr=t&pd_rd_r=d05d4f97-7e12-4879-a27e-61552a925ee8&pd_rd_w=rtX3a&pd_rd_wg=1uDCP&ref_=sbx_be_s_sparkle_mcd_asin_1_img
Or search for 'battery 12v to 120v power supply regulated' and find other solutions.
But I agree with Bassam not to use a non-Yamaha approved adapter unless you want to assume the risk if things go horribly wrong.
[/quotePost]
budget is "whatever looks modest for a school project"
Posted : 05/05/2022 4:09 am
A "D" battery would, on paper, last about 4x longer. It's not difficult to wire up but I wouldn't advise connecting directly without regulation. I say this because as the battery depletes I'm not sure what the voltage/time curve will look like with MODX drawing power. I'm not sure how long the battery will be able to provide a "brownout" voltage that's under spec for operation but higher than 0V high enough to be in "no man's land". Sticking a switching, LDO, or buck/boost regulator between (12V in, 12V out) will reduce the runtime due to the efficiency hit - but the regulator I would advise would monitor "power good" at a the lowest acceptable voltage and cut off the power if the output voltage dropped below this level even when the regulator is enabled. This would cover the case where the batteries cannot source the required current and start bringing down the input voltage.
I think the "easiest" thing (see below some elaboration on what goes into "easy" ) to do is to take a car or "motorcycle" 12V battery and hook up an inverter. Even if you had to buy the battery - the supplies would be around $50 for the inverter+battery.
Home Depot sells (online, not in store) 12V batteries and one at $26 shows it will run the MODX if it was pulling maximum power for 5 hours. Factoring in inefficiencies maybe I'd derate this to 3.5 hours (still assuming the full 1.5A draw from MODX continuous - which is an aggressive value - assuming about 73% derating here). This assumes using the inverter.
Certainly buying a UPS would be easier since it self-contains everything together. However, I'm factoring in the price as part of the "easy" equation. So yes, a little more modular and more sub-components - but pricing is balanced here.
You can pick your own balance of pros/cons here however - as there isn't necessarily a best answer.
Note: AA batteries assumes the MODX is sipping power. I don't have the typical power measurements to know if 250mA (of 1.5A max) is reasonable. If drawing 1A+ then the voltage is likely going to droop too much off of AA. A "D" battery would have to assume MODX sips a little more (around 600mA - still much less than the max of 1.5A).
A larger battery (than 8xD in series) would better ensure you don't short-change the current capacity. And adding the inverter would kill ~30% of the runtime - but also provide piece-of-mind with regulation and using the official power supply giving you a safety buffer.
Posted : 05/05/2022 7:33 am
Topic starter
[quotePost id=116569]
budget is "whatever looks modest for a school project"
Excellent! Now we have a target price to shoot for.
How cheap are potatoes where you live?
https://stemgeneration.org/potato-power/
Gather these supplies:
3 Fresh clean potatoes – acidic electrolyte
3 Galvanized nails (or screws) – they have a zinc coating and will be used as your zinc electrodes
3 US Pennies (or copper wire with exposed copper end) – Pennies newer than 1982 are thinly copper-plated, while older ones have more copper. The pennies will be used as your copper electrodes
5 Dual alligator clip connectors (10 actual clips total) – you can find these at most hardware or electronic stores
1 LED clock that has a battery compartment
This solution has some advantages over those other ones offered:
1. you can eat two of the potatoes after this project is done
2. you can plant 'eyes' from the 3rd potato to grow the ones needed for the next project
3. you can use various varieties of potatoes from different countries
4. it is educational - perfect for that school assignment
5. no 'ground loop' or similar problems since you can use a separate 'potato' source for the instrument and speakers.
You WILL need to compute the number of potatoes needed. That calculation can be complicated because the output will depend on the individual characteristics of each potato that you use.
Tell your daughter good luck with her project!
[/quotePost]
This would all be incredibly motivating if I could just get salt and vinegar chips out of this process.
Posted : 06/05/2022 4:09 am
