Amateur's Build your own charger

Amateur

10 mW
Joined
Aug 7, 2019
Messages
25
Hello and thank you for the wounder contributions to the Endless-Sphere! Wile I was thinking up ways to not buy a ridiculously overpriced legit charger
I came up with an Idea that may "shock" you!
Take a very cheap harbor-Freight variable speed control ment for a Universal motor run its output through a Bridge rectifier than through a large filter
Cap then to a JLD5740TV (google) then you have you're self a 170 volt (unloaded) and up to 30 amps or what ever your house was wired with for a standard 120 volt Outlet. Ps the dryer Outlet in my house is single phase 220 cut in half is 30 amp 120v line! My wife hates me......
 
Amateur said:
Hello and thank you for the wounder contributions to the Endless-Sphere! Wile I was thinking up ways to not buy a ridiculously overpriced legit charger
I came up with an Idea that may "shock" you!
Take a very cheap harbor-Freight variable speed control ment for a Universal motor run its output through a Bridge rectifier than through a large filter
Cap then to a 5740TV (google) then you have you're self a 170 volt (unloaded) and up to 30 amps or what ever your house was wired with for a standard 120 volt Outlet. Ps the dryer in most house is single phase 220 cut in half is 30 amp 120v line! My wife hates me......

you forget that its horrliby inefficent.
 
average cheap VFD efficiency is 85% to be on the generous side.
then a bridge recemfryer wich also cuts off another 20~25% in losses (at least!) so you end up with about 40% in wasted energy.

single step charger desinged for the load in question can get well beyond 90% efficiency as seen in the mean well HLG and ELG series.

so you are building a rube goldberg style space heater that happen to also charge a battery -poorly-.
 
Not trying to offend you or hurt your feelings.
The acronym VFD stands for Variable Frequency Drive. converting a 60 hertz sinusoid to a higher/lower frequency. But i am sure that you already knew that. The "router speed control" uses a TRIAC part number BTA-26 to manipulate the sinusoid. not increase or decrease its frequency. As for efficiency I'm not too sure but at 15 amps the heat sink I use has both the bridge rectifier and a TRIAC and gets to 100° F The full bridge diodes do have a loss FVD. and the TRIAC can only manipulate the sinusoidal. I am not to sure you have all the facts are straight in your last post. Again not trying to offend or anger anyone. Let me know if anyone can chime in and correct both of us
 
a VFD works by first -rectifying- the input and then converting it back into the AC you want.
yes,i know how it works,i had to learn this crap for my degree so i dont mind.

see here:

Fig2-Circuit-diagram-of-variable-frequency-drive.png


see the recifier in blue? yeah, that is your first 20+% losses there, the rest is heat losses in the IGBT section. especially a crappy one with cheap parts will not be efficient.

not sure where you need a triac in a VFD.
 
I'm not sure who's more confused you or me.
I to dabble in the world of power electronic design. switch mode topologies is my specialty.
Just wanted to offer a bit of cheap knowledge for anyone willing to build inexpensive extremely dangerous charger that works well.
 
pretty sure i understand the topology of a VFD,
considering you mentioned a universal motor i am pretty sure you are confusing a VFD with a basic triac dimmer circuit.
and someone that "dabbles" in the power electronic design (whatever that means) should know that a VFD does not have triacs but IGBT's.

while a triac circuit can do what you want to do it in this case it is seriously the wrong tool for the job. running a triac based DC voltage control is extremely cheap but also extremely dangerous as a simple flic of a knob can dump more then 150 or 300VDC (depending on continent) at full mains current directly into a battery designed for a fraction of that.

while -technically- your idea can work does not make it a good one. charging batteries with a uncontrolled power source like a triac is just dangerous and should not be recommended in any way.
 
You have made many assumptions. And that's OK we all do it. Also Google JLD5740TV. Once again you assume someone would plug battery pack directly into a wall... you assumed the term Universal motor is the type that some needs frequency control. You know the type of motor with electromagnets magnets and an Armature with a the type commonly found in household appliances.
Any way good luck in all future endeavors
 
Amateur said:
You have made many assumptions. And that's OK we all do it. Also Google JLD5740TV. Once again you assume someone would plug battery pack directly into a wall... you assumed the term Universal motor is the type that some needs frequency control. You know the type of motor with electromagnets magnets and an Armature with a the type commonly found in household appliances.
Any way good luck in all future endeavors
please enlighten me on what someone should do with that google number, because i can only find a expensive voltmeter. nothing that would give me a indication to charge a battery on the cheap with.
and no, i dont "assume" a universal motor needs variable frequency. you give the ideeea that you are using a triac to control voltage. something that is extremely dangergrous on a variable load like charging a battery.
so you have me at a loss on what you are on about because you dont make much sense without being a LOT more specific or just show the setup. i dont see how you can charge a battery with a uncontrolled triac based power source without burning your house down. the only way i can see how you do this with any safety is with a proper VFD, not crappy triac dimmer.
 
Request to mods, split from #120 of this great thread off into a new one?

Really not the same topic. . .
 
Sorry john61ct I will stop. I was just trying to show how I made my charger that's all
 
No please a detailed HowTo build thread with order links, spec sheets would be most welcome, and even if dangerous or impractical torn apart by Flippy or a whole crowd, would still be educational.

Just saying, that topic deserves its own thread, please start one, they're free!
 
------links------

https://www.lightobject.com/Electronics/Digital-Panel-Meter/Volt-Meter/Programmable-4-Digit-Red-LED-ACDC-Volt-Meter-with-Dual-Control-Good-for-HHO-System

https://www.mouser.com/ProductDetail/Vishay-Semiconductors/GBPC3504-E4-51?qs=AvlKB63p5Skbseqoy9rxVg%3D%3D&gclid=EAIaIQobChMIqJfKppGk5AIVksVkCh1qMQsMEAQYASABEgLe8PD_BwE

https://www.ebay.com/itm/Mallory-1014336-00-Type-CG-4500uF-200V-screw-terminal-electrolytic-capacitor-/400748858773

https://www.amazon.com/Dorman-88069-Universal-Pin-Relay/dp/B00NF0ICSO

https://www.ebay.com/p/15-Amp-Pushbutton-Circuit-Breaker-Joemex-PE7415-15a/1165020604?iid=262373362224&chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=262373362224&targetid=503482145964&device=m&mktype=pla&googleloc=1022494&poi=&campaignid=1669934822&mkgroupid=65058350059&rlsatarget=pla-503482145964&abcId=1139296&merchantid=101689895&gclid=EAIaIQobChMIv_yBoJOk5AIVWB-tBh3MdASOEAQYAyABEgIwPfD_BwE

Have been using this charger for 4 years now almost daily no problems yet if any one would has questions let me know
 

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You can also use ebay/amazon cc/cv boost converters designed expressly for this purpose with trim pots instead of knobs so you don't accidentally send your battery to 6v/cell.
 
I am not sure of that without more information on your set up.... all I can say is that what I have used works for me....but I am sure it depends on the current voltage level that you are trying to achieve
 
so how do you control the CC/CV exactly and how do you prevent sending full recitifed mains into the battery if your regulation fails?
 
Amateur said:
The "router speed control" uses a TRIAC part number BTA-26 to manipulate the sinusoid. not increase or decrease its frequency.

Teardown of a router speed controller:

[youtube]n_uK2G4qFG4[/youtube]

Not all speed controllers are VFDs, although many of the good ol' alternatives are pretty horrible by comparison.
 
Flat tire the type of pot that I have utilized is lockable. And the only pot is for establishing base/max current the 5740TV takes care of the rest. This is not cc/cv this is a cv charger I set the charge currant the 5740TV takes the pack off line when the cells all reach 3.5 volts my last pack had 30 A123 20AH Cells 105 volts the new pack has 37 38120 That is 129 volts. All cells are bottom balance. No BMS to speak of....
 

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no CC, so you made a power supply, not a charger.

still wondering what happens if the regulation fails.
 
flippy. The base current is set buy the pot only the side of the case and that is independent of voltage to a point. But i am sure you know all about this as this is Elementary level power control. Let me ask you what happens when any powersupply fails. S#÷t goes awry as I am sure you are aware. I have no Vendetta against you. Yet it seems you have one against to me. My only goal here on this forum is to Enlighten people. Of the fact that there is a easier, cheaper way to charge a battery packs above 100v @ 10-30 amps and at roughly $200 price point that can't be beat. Trust me I've looked..... the only problem with my charger design is that it's not isolated. I am fully aware of that and the fact and i know that it can be quite fatal if mistreated. If you want to attempt to keep slandering my ideas ,by all means. maybe in your spare time if you could spare $200 as a bench test to find the faults in my design please enlighten me I'm looking forward to the results..... good luck
 
this has nothing to do with vendettas. i dont care about petty squabbles, i am just to the point and my questions are directed to the device and its design, not you personally.
its nice you want to share your experiences by being as cheap as possible and that is welcomed, what should not be welcomed is a instruction to build a device that can kill other forum members or can easely cause a battery to recieve up to 350VDC recitfied mains into a battery and not even mention it unless asked and even downplay the issues with this design.

the fact this supply is not isolated means that you get full uncontrolled mains on the output when either the bridge or triac fails.
isolated switching supplies usually fail safe, so the ouput generally simply dies when a massive failliure happens in a power component.

your way of controlling voltage and current is "unique" shall we say and considering the price point is still debatable since a single falliure of the supply can instantly destroy your expensive battery and probably your house as well.
that you did not burn your house down (yet) is not emperical evidence that your setup is safe.

personally i dont like saving a few bucks on a component that is capable of destroying your expensive battery (and your house). spending a bit more so you can realiably and safely take care of your investment is a more reasonable position.

200 bucks is fine, but its not the same then what a normal charger can deliver in features like proper CC/CV control so this project should be earmarked properly as being unsafe and with a risk of killing your battery (and house) if a component fails open.

i build plenty of power supplied for various projects and even a couple lab supplies but building a setup like this makes no sense to me unless one would be stuck in the desert and need to power something.
right now i outsource power supplies and just buy genuine mean well and be certain they will live longer then whatever they are mounted in. prehaps more expensive but in the long run its probably a lot cheaper as i know that my charger wont put mains directly on my battery tabs and just blow a (hrc) fuse or in the worst case a pop a diode or mosfet instead of blowing up my workshop.
 
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