DIY incubator... 120v AC to 12V DC transformer questions...

[CD CONSTRICTORS]

Got a nice little wine cooler on the cheap from CL... really nice unit with a glass front.

Anyways, here is my issue. There is already 120v AC coming in to supply a 10w switched bulb inside. Switch is on the front so I can just turn it on to take a peek inside whenI want. I left this wired up.

Problem is this.. I got a simple 120v AC to 12v DC transformer from radio shack to run my 120mm fan on a rheostat. Two black wires on the input- supposed to tie into black and white from 120v AC, but neither is labeled white or black on the transformer?? Does it matter? Cause it doesn't work, no matter which way I wire it. My fan works right off a 12v battery and also works off a cheap old wall plug transformer that is only a 5v transformer... rheostat wired up and all, it works.

Like I said this transformer has TWO BLACK wires on the input- neither labeled. Three wires on the output.... two yellow and one black. Two yellow together gives you 12.6v DC out. One yellow/one black tied together gives you 6.3v DC output. Well... I get nothing from either. Where does the fan negative wire attach to? The frame of the unit, or the white wire from the AC... which is what I read on the DIY thread here.

So, do I have it wired AFU, or is the transformer just bad? The minimum wage idiots at Radio Shack didn't even know what a rheostat was when I asked where they were....

[The Serpent Merchant]

Can you post a picture or link of the transformer?

[CD CONSTRICTORS]

Pics attached... Radio Shack Part number is 273-1352A. I am only anticipating possibly 2 and maybe 3 clutches this year, so this was a nice size for me starting out. I have another mini-fridge that's already gutted, but I like the glass front better. Any help would be appreciated. TIA.

Work in progress... just need to fix this transformer issue and install my Flexwatt.


Transformer

[The Serpent Merchant]

Polarity does matter, I couldn't find anything that identifies which of the black wires is the + and which was the - Just try both ways.

I think your problem is the fan ground. the fan ground should connect to the black wire on the output side, and both yellows should connect to the fans +

[jason79]

No it does not matter on the line side hook one black to the hot the other to neutral. On the load side cap the black and hook the 2 yellows to the fan for 12 volts you only use the black if you want 6 volts. If it spins the wrong way reverse them on the load side. You also need to have a gap between the fridge and the fan in order to get air flow.

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I think your transformer is putting out 12 v AC though not DC this might be your problem

[The Serpent Merchant]

No it does not matter on the line side hook one black to the hot the other to neutral. On the load side cap the black and hook the 2 yellows to the fan for 12 volts you only use the black if you want 6 volts. If it spins the wrong way reverse them on the load side. You also need to have a gap between the fridge and the fan in order to get air flow.

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I think your transformer is putting out 12 v AC though not DC this might be your problem

This is correct, I misread the box.

[CD CONSTRICTORS]

It completely overlooked the 12vAC. When I see 12v I was thinking 12v DC cause that was the fan I had just picked up....

I'll sort it out tomorrow. At least I know the problem now. Thanks for keeping me in check guys!!

It doesn't look like it, but the fan has 2 1/2" clearance from the top.... thats plenty of clearance to pull a little air and keep air circulating.

[jason79]

You may have issues with it working properly on the reostat also. Most of them are not rated for motors it might work but It may greatly reduce the life of the motor though.

[CD CONSTRICTORS]

No problems with these fans at all on a rheostat.... at least not the 4 fans in my computer. I've had 4 of these same fans running 24/7/365 for the most part of the last five years (less at most a month when I moved or went on an extended vacation).

I can run them from 900rpm up to 2700rpm, but mostly keep them around 2100rpm. Nice and quiet and they keep my water cooling nice and stable. Blue lights are the rheostats... two fans running on each. Two pushing into the radiator and two pulling from the radiator (shown in 2nd pic). Eventually I'm going to put one of these bay fan controllers in my incubator. They have two fan controllers and two temperature sensors. It would be handy to monitor temps in the top and bottom of the incubator and control the fan from one piece of equipment.