Problem with Power Supply and Ammeter/Voltmeter display Advice

Thread Starter

HHOtesla

Joined Feb 9, 2019
5
Hey there!

I´ve been working on my bench HHO generator for a year now and ran into all kinds of set backs, the latest being my 12V 60A power supply blowing up (my mistake) and not being able to get proper/accurate readings from many of my Voltmeter/Ammeters LED displays with external shunts.
After blowing my first PSU, I ordered another one, virtualy the same one, and as soon as I plug in the AC my house lights went out. It obviously came untested and defective.
I open it up and couldn´t find a fuse, anything burned or a phisical short. What could I do about it?

Here is the link: https://www.ebay.com/itm/110V-220V-to-DC5V-12V-24V-48V-Switch-Power-Supply-Driver-Adapter-LED-Strip-Light/142462540092?ssPageName=STRK:MEBIDX:IT&var=441462113857&_trksid=p2060353.m2749.l2649

I should mention that I´m using a 100A capable PWM, even though I will only be pushing 50A through the 21 plate Cell (12V), wich was starting to push the PSU to it´s max. So I ordered the meter with a 100A Shunt so it would have some margin.

Regarding the ammeter/voltmeter display, I bought many of these cheap LED displays with external shunt off ebay (100A shunt):

https://www.ebay.com/itm/DC-100V-50...8a083b7eb:m:mHY20U0Ke_v6ujQYuW3PEOg:rk:1:pf:0

I wired the led meter as it shows in the pretty diagram. This way it powers it self from the same source and should give me both V and A reading but that´s not the case. It shows V alright but stops at 2A
(In my drawing, forget the "yellow and blue", that´s from a different meter, I wired it has it shows in the diagram.)

*The only time I got a good reading was when I used a smaller 50A shunt and a diferent meter with only A reading. It would read all the way to 60A despite heating up quite a bit. Using that same meter but with the 100A shunt, It only climbed to 20A! I think part of the problem is the shunt I´m using idk.

I tried moving the shunt between the PSU and PWM, instead of between PWM and Cell (It´s how it is now), with the same result.
If you spot any error on the diagrams, please let me know!
If my meter is somehow broken, I was considering buying this one from Ali:

https://www.aliexpress.com/item/ATO...&terminal_id=0f866152f0af467ba52d4c68b8f7b64a

Any thoughts on this one? Could it handle the 50A? Or are there better ones considering my set up?
 

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Thread Starter

HHOtesla

Joined Feb 9, 2019
5
It is much more intelligent to buy a car battery and charger.
Not on this set up Colin.

Since my PSU is dead, today I tried using a car battery (it has large capacity) and I couldn´t get full gas production. By it self the battery didn´t have enough juice. I had to start the car to get input from the alternator.

Even if it could provide enough juice, led-acid bateries are still expensive, heavy beasts, and are not designed for continuous high current draws like 50A. Not practical at all as a bench power source.
 

spinnaker

Joined Oct 29, 2009
7,830
Hey there!

I´ve been working on my bench HHO generator for a year now and ran into all kinds of set backs, the latest being my 12V 60A power supply blowing up (my mistake) and not being able to get proper/accurate readings from many of my Voltmeter/Ammeters LED displays with external shunts.
After blowing my first PSU, I ordered another one, virtualy the same one, and as soon as I plug in the AC my house lights went out. It obviously came untested and defective.
I open it up and couldn´t find a fuse, anything burned or a phisical short. What could I do about it?

Here is the link: https://www.ebay.com/itm/110V-220V-to-DC5V-12V-24V-48V-Switch-Power-Supply-Driver-Adapter-LED-Strip-Light/142462540092?ssPageName=STRK:MEBIDX:IT&var=441462113857&_trksid=p2060353.m2749.l2649

I should mention that I´m using a 100A capable PWM, even though I will only be pushing 50A through the 21 plate Cell (12V), wich was starting to push the PSU to it´s max. So I ordered the meter with a 100A Shunt so it would have some margin.

Regarding the ammeter/voltmeter display, I bought many of these cheap LED displays with external shunt off ebay (100A shunt):

https://www.ebay.com/itm/DC-100V-50...8a083b7eb:m:mHY20U0Ke_v6ujQYuW3PEOg:rk:1:pf:0

I wired the led meter as it shows in the pretty diagram. This way it powers it self from the same source and should give me both V and A reading but that´s not the case. It shows V alright but stops at 2A
(In my drawing, forget the "yellow and blue", that´s from a different meter, I wired it has it shows in the diagram.)

*The only time I got a good reading was when I used a smaller 50A shunt and a diferent meter with only A reading. It would read all the way to 60A despite heating up quite a bit. Using that same meter but with the 100A shunt, It only climbed to 20A! I think part of the problem is the shunt I´m using idk.

I tried moving the shunt between the PSU and PWM, instead of between PWM and Cell (It´s how it is now), with the same result.
If you spot any error on the diagrams, please let me know!
If my meter is somehow broken, I was considering buying this one from Ali:

https://www.aliexpress.com/item/ATO...&terminal_id=0f866152f0af467ba52d4c68b8f7b64a

Any thoughts on this one? Could it handle the 50A? Or are there better ones considering my set up?

Why not just send it back, instead of messing with the supply?

You really need to organize your thoughts. A lot easier to deal with one problem at a time.
 

Thread Starter

HHOtesla

Joined Feb 9, 2019
5
Why not just send it back, instead of messing with the supply?

You really need to organize your thoughts. A lot easier to deal with one problem at a time.
Sending it back to China is out of question due to costs.
I was hopping it could be salvaged somehow.

Well sorry if it's a bit confusing. Im quite frustrated with this simple wiring and wanted to explain it with detail.

Can you tell me why isn't the meter working based on my drawing? (The meter as a red and yellow wires that connect to + Load)
 

Thread Starter

HHOtesla

Joined Feb 9, 2019
5
I don't want to use too much of my electronics understanding to answer this problem, but:
Use 2 batteries in series.
Why are you trying to give advice when you seem to have no understanding in the first place....

2 car batteries in Parallel would be more "inteligent", but in case you didn´t notice, they wouldn´t fit inside that PC shell.
 

spinnaker

Joined Oct 29, 2009
7,830
Why are you trying to give advice when you seem to have no understanding in the first place....

2 car batteries in Parallel would be more "inteligent", but in case you didn´t notice, they wouldn´t fit inside that PC shell.

And would not last very long at that current, without recharging that is. ;)

Are you going to return it? I think that is your only hope. That is the problem with the cheap Chinese stuff on eBay. You never know what you are going to get. Not to mention the safety issues. So if you get this straightened out, I would not use it unattended if I were you. and be very careful with touching the supply. Make sure another part of you is not touching ground when you touch the case. Those cheap supplies on notorious for having poor or in some cases, no grounding.
 

Thread Starter

HHOtesla

Joined Feb 9, 2019
5
And would not last very long at that current, without recharging that is. ;)

Are you going to return it? I think that is your only hope. That is the problem with the cheap Chinese stuff on eBay. You never know what you are going to get. Not to mention the safety issues. So if you get this straightened out, I would not use it unattended if I were you. and be very careful with touching the supply. Make sure another part of you is not touching ground when you touch the case. Those cheap supplies on notorious for having poor or in some cases, no grounding.
That would be a good way of melting the poles and boiling the acid out of the battery :p

I sent them a video "proving" it doesn't work. They said a replacement is coming! I learned that if you are gentle and polite with Chinese sellers they usually help you out. Also, saying you want to buy more quantity works at your favor! Ahahah

Funny you mention that because I got shocked alot with my old one. Better insulate it next time....
Thanks for the heads up :)
 

spinnaker

Joined Oct 29, 2009
7,830
You might want to look at being sure the case is properly grounded on the next one. I would ask for advice here on the proper way to do that. But I still would not let it run unattended. ;)

I have had good luck on getting returns and like you, they did not want the old one back.
 
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