LED Power? What transformer should i use?

[AdamLucko]

Ok. The pictures should tell it all but here we go!
I was at a pub the other day and I noticed that beside the can was a box, so i veered in and noticed that there were 2 beer towers that were slightly used. I smiled When I got back to my seat I asked the waitress if i could talk to the manager or owner. I assured her she did nothing wrong and it was about a purchase. She then showed me to the bar where the owner was sitting. I asked him if I could purchase the 2 sets of taps from him for 100$ each. He looked at me and said "buddy! I appreciate your business here, so just take em and enjoy" I then took them and put them in the back of my jeep. Went back in and create a hefty bill well worth the money I was going to spend.

Now My problem is. It came with no power cord to plug it in. All the wiring is sound but for the life of me I cannot find what power source to use. When I went to the golf course they had a very similar tower. and I asked if I could take a picture of the transformer? So here are the pics of everything. I need to know where I can find the right power source for these cool taps! Brand is Celli, Tower is Zenith, The lights were an add on also from Celli.

Where can I buy the specific power source

 

[day_trippr]

It looks like a 110VAC to 12VDC "wall wart" power supply rated for 2A will do the job (the model pictured is actually rated for 1.67A so you'd have a little extra headroom - not a bad thing).

For instance, something like this with a little modification (basically, cutting off the plug and connecting the wire to your tower wiring) should work...

Cheers!

 

[pointcity-homebrew]

The pictured transformer is a 120VAC to 12VAC, see link below. Wonder if there is an AC-DC converter in the unit?



http://leeselectronic.com/en/product/10641.html

 

[AdamLucko]

I just attached them to a 12V battery (from a drill) and they work great, however, would this mean I need a converter of some sorts? ALso thanks for the quick info guys! your awesome!

 

[pointcity-homebrew]

I just attached them to a 12V battery (from a drill) and they work great, however, would this mean I need a converter of some sorts? ALso thanks for the quick info guys! your awesome!

No, in which case you can use the transformer mentioned by day tripper.

 

[AdamLucko]

I just a tag on it that says 12V 50HZ, is this typical? I am in Toronto, Ontario Canada, do we not use 60HZ here? Would this matter?

 

[AdamLucko]

https://www.amazon.ca/gp/product/B019Q3U72M/?tag=skimlinks_replacement-20

Would this work?

 

[pointcity-homebrew]

I just a tag on it that says 12V 50HZ, is this typical? I am in Toronto, Ontario Canada, do we not use 60HZ here? Would this matter?

That rating would be pertaining to AC voltage. As far I know you guys are 60Hz just as we are.

That transformer should work.

 

[day_trippr]

Sure, that'd work fine.

I figured the lighting was LEDs but apparently it's incandescent, so you could use a 12VAC wall wart - essentially an unrectified transformer all by its lonesome - but I suspect the price differential would be negligible...

Cheers!

 

[AdamLucko]

Thank-you! You both made my day! Now off to buy this on amazon!

 

[pointcity-homebrew]

Sure, that'd work fine.

I figured the lighting was LEDs but apparently it's incandescent, so you could use a 12VAC wall wart - essentially an unrectified transformer all by its lonesome - but I suspect the price differential would be negligible...

Cheers!

This is what I was thinking when I saw the AC rating.
However, if you look at the pic you can see the led and resistors. Wonder is someone did a mod on it and added the led strips?

 

[passedpawn]

The pictured transformer is a 120VAC to 12VAC, see link below. Wonder if there is an AC-DC converter in the unit?



http://leeselectronic.com/en/product/10641.html

LEDs should work just fine on an AC supply. They'll half-wave rectify the AC.

 

[pointcity-homebrew]

LEDs are not good rectifiers, just as rectifiers aren't good LEDs. Just the higher forward voltage drop, ~1.5-3V compared to .7V, makes them insufficient, at least in theory.

I had a group of senior design students that were having an issue with their LED strip blinking and dimming. Come to find out they grabbed a AC transformer off the shelf vs DC.

 

[passedpawn]

LEDs are not good rectifiers, just as rectifiers aren't good LEDs. Just the higher forward voltage drop, ~1.5-3V compared to .07V, makes them insufficient, at least in theory.

I had a group of senior design students that were having an issue with their LED strip blinking and dimming. Come to find out they grabbed a AC transformer off the shelf vs DC.

Er yea, I wouldn't use an LED in a switching pwr supply design. But driving them with AC would work, but they're would be some slightly perceptible blinking that would eventually drive everyone crazy I'm sure. They'd only be on for half the cycle, and then they'd be driven by that half cycle of a sinusoidal. Now, if those LEDS were arranged in a bridge pattern, no blinking, but white LEDs are expensive and it'd be cheaper still to rectify to DC first and use half the LEDs.

BTW, maybe a typo on your part, but standard all-silicon diodes are 0.7V, and Schottky are 0.25V. The white LEDs (blue with yellow phosphors) are about 3V.

 

[pointcity-homebrew]

Yep, I added the zero by mistake.

It appears that the unit in question works with a 12Vdc supply.