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Subaru
1-3-2-4
Premium
join:2001-05-31
Greenwich, CT
kudos:1

DC power adapter

What makes these things one day just not work anymore? I'm talking about not being plugged up for like 2-3 years

I have one from a waterfall pump that's 12V 400mA

it's just annoying because this is like the 3rd one that's gone out like this.



shdesigns
Powered By Infinite Improbabilty Drive
Premium
join:2000-12-01
Stone Mountain, GA

The primary windings are real thin. They can corrode off.

They are most all over rated for their use. They overheat and the windings short out then open. Get a higher current one and it will probably last longer.



Subaru
1-3-2-4
Premium
join:2001-05-31
Greenwich, CT
kudos:1

I was thinking about getting one that lets you switch voltages and has a max output rating of 1.5A



tschmidt
Premium,MVM
join:2000-11-12
Milford, NH
kudos:9

1 edit

Within reason larger is better. Larger rated unit wastes more power so you don't want to get carried away.

Try getting a switching power supply rather then transformer, as there are more efficient.

/tom



leibold
Premium,MVM
join:2002-07-09
Sunnyvale, CA
kudos:10
Reviews:
·SONIC.NET
reply to Subaru

Some electrolytic capacitors don't store well and actually last much longer when they are used instead of being powered off for extended periods of time.
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aurgathor

join:2002-12-01
Lynnwood, WA
kudos:1
Reviews:
·Frontier Communi..

1 recommendation

reply to Subaru

said by Subaru:

What makes these things one day just not work anymore?

One sure way to find out is to take it apart, and do a post-mortem.
--
Wacky Races 2012!


cowboyro
Premium
join:2000-10-11
Shelton, CT
reply to Subaru

One bad adapter.. ok, it happens.
Second adapter going bad... hmmmm...
When the device goes through the third power adapter I'd start looking into the device... why is it frying the adapters?



Subaru
1-3-2-4
Premium
join:2001-05-31
Greenwich, CT
kudos:1
reply to leibold

said by leibold:

Some electrolytic capacitors don't store well and actually last much longer when they are used instead of being powered off for extended periods of time.

This one is a transformer so maybe the wire broke or whatever, but I'm sure my others that used caps that could be the case.


Subaru
1-3-2-4
Premium
join:2001-05-31
Greenwich, CT
kudos:1
reply to aurgathor

said by aurgathor:

said by Subaru:

What makes these things one day just not work anymore?

One sure way to find out is to take it apart, and do a post-mortem.

lol I cracked the case open and once I saw the transformer it can't be worth it to mess with it, besides the cable was too short.


aurgathor

join:2002-12-01
Lynnwood, WA
kudos:1
Reviews:
·Frontier Communi..

1 recommendation

If you already opened it up, it shouldn't be much extra work to measure the windings, and if they are good, measure the other parts (rectifiers and probably one or two caps).
--
Wacky Races 2012!



Subaru
1-3-2-4
Premium
join:2001-05-31
Greenwich, CT
kudos:1

Click for full size
Click for full size
A little look inside


tschmidt
Premium,MVM
join:2000-11-12
Milford, NH
kudos:9

Buzz out the winding to see which one is open, primary or secondary,

You said this was a DC wall wart - where is the bridge rectifier and filter cap?

/tom



Subaru
1-3-2-4
Premium
join:2001-05-31
Greenwich, CT
kudos:1

said by tschmidt:

Buzz out the winding to see which one is open, primary or secondary,

You said this was a DC wall wart - where is the bridge rectifier and filter cap?

/tom

buzzz lol good catch I must of looked at it a little too fast it's 12VAC 400mA don't own many of those!


cowboyro
Premium
join:2000-10-11
Shelton, CT
reply to Subaru

Could it be a DC motor that you're feeding with a "broken" AC source?



Subaru
1-3-2-4
Premium
join:2001-05-31
Greenwich, CT
kudos:1

I doubt it since the pump has the 60hz marking on it.. just thinking about it I do have another ac adaptor I just have to check the rating on it


TheMG
Premium
join:2007-09-04
Canada
kudos:3
Reviews:
·NorthWest Tel
reply to Subaru

Most of these wall wart transformers have a thermal fuse buried deep within the primary winding.

Even a overloading the transformer will lead to the thermal fuse blowing. Sometimes they occasionally blow without being overloaded since these transformers can run hot, or are overrated.



Subaru
1-3-2-4
Premium
join:2001-05-31
Greenwich, CT
kudos:1
reply to Subaru

OK the ac adapter I have is 12VAC 1.2A

But just seeing I set my meter to AC I see 17V on it, so it's something with the pump, it's one of those stupid wheel switches on the cord, so given that the light is blown on it I can probe that area to see when the pump should be on, I don't know if I can open the pump, maybe it got stuck with stuff? I don't think a 4W pump would make any type of locked rotor sound?
--
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Subaru
1-3-2-4
Premium
join:2001-05-31
Greenwich, CT
kudos:1
reply to Subaru

Click for full size
Click for full size
Click for full size
So this is the pump


SparkChaser
Premium
join:2000-06-06
Downingtown, PA
kudos:3

well, it sure says AC. Which limits your possible problems.



Subaru
1-3-2-4
Premium
join:2001-05-31
Greenwich, CT
kudos:1

True well I got the pump kinda open, to the point where the front and back cover is off but the part where the impeller sits on the motor hub that seems to be the cause of it not wanting to turn, and turning it by hand with it on is some major resistance.

Geeez I was just expecting to replace the bulb with an LED...



Subaru
1-3-2-4
Premium
join:2001-05-31
Greenwich, CT
kudos:1
reply to Subaru

Oh well unable to save the pump (I already cut into it) somehow the inside is really locked up, maybe it ran low? It's been so long I can't remember..

I was thinking about maybe getting a stronger pump? I have another here but the cable is a lot thicker and this one is 120V if I'm correct.. I'm curious to see what happens with a stronger pump with a small fountain.



leibold
Premium,MVM
join:2002-07-09
Sunnyvale, CA
kudos:10
Reviews:
·SONIC.NET

said by Subaru:

I'm curious to see what happens with a stronger pump with a small fountain.

Just a guess:

small fountain => big fountain



Wear your raincoat when you try it out
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aurgathor

join:2002-12-01
Lynnwood, WA
kudos:1
Reviews:
·Frontier Communi..
reply to Subaru

said by Subaru:

True well I got the pump kinda open, to the point where the front and back cover is off but the part where the impeller sits on the motor hub that seems to be the cause of it not wanting to turn, and turning it by hand with it on is some major resistance.

Geeez I was just expecting to replace the bulb with an LED...

Looks to me you didn't much (if any) initial trouble shooting before blaming it on a (probably not) faulty AC/DC power supply....

Most of the time, you should start with checking the power (AC and/or DC voltage), and go from there.
--
Wacky Races 2012!


Subaru
1-3-2-4
Premium
join:2001-05-31
Greenwich, CT
kudos:1

I did but I used the wrong setting on the meter, one thing I don't like about this pump here is it has no on/off switch however it's a bit more robust.. the bearing had to be taken out but it's listed as a Techna + Technolab 115v AC 60Hz 6W 0.1A

Max Lift 2'
GPH 0-90



Subaru
1-3-2-4
Premium
join:2001-05-31
Greenwich, CT
kudos:1
reply to Subaru

Click for full size
Click for full size
Click for full size
Well for the time being I just put an LED strip above the fountain, now comes the fun part of trying to fit everything in a tiny bowl...


Subaru
1-3-2-4
Premium
join:2001-05-31
Greenwich, CT
kudos:1
reply to Subaru

Click for full size
It's not crazy with the power but it's just right, it is a tight fit however... I would switch bowls but that plastic holder is what holds the rocks and the top rock is what's the output for the water.