Need help with wiring

[2cranky]

I want to wire up a couple of pc fans and led light strip inside my keezer. I've got a flooded font and the lid on the keezer is glass. So I thought it would be a good idea to wire the leds to the pump switch this way I'll be less likely to leave the pump on.
So I mounted the pc fans and the led strip. This was left over from another project so I had to solder new wires on it. After that I've tested both with a car battery and all good.
Next step I wanted to put the transformers in an old T box with my STC that controls the freezer.
I've wired a 240v feed through two switches where they power the 240v pump and the 12v leds through a transformer on one and the pc fans through another transformer on the other switch.
I used the little electronic transformers that you use for 12v downlights.

Once I'm done I turn it on and it doesn't work. I tested the transformers with a downlight and they seem to be okay.
On closer inspection the leds are on but only a couple close to the input wires and these are only dull and flickering a bit.


So what gives? This really has me stumped.

Cheers.

 

[n87]

trusty multimeter.
Probe the output of the transformers, make sure they are putting out 12v.
check that you have wired them round the right way

I suspect that there isnt enough load for the transformer to bother turning on (some dont get up for anything less than x ohm).
Test with a standard 12v PSU wall wort

 

[captain crumpet]

If it's one of those cheap electronic trannies for downlights id suspect that. I dont know much about leds but i do know they are sensitive to voltage and current.

 

[2cranky]

I've only got an old multi meter that might not be too accurate but tests ok on the battery. Ok on the 240v. But only milli volts on the transformers out. But like I said lights up the 35w globe ok.
So do I need to get a different type of transformer. I didn't realise these switch on and off for load.

 

[2cranky]

12v PSU wall wort

Sorry I don't know what this is?

 

[n87]

Sorry I don't know what this is?

https://www.google.com.au/search?q=...PHUAhWKnZQKHQOsDVkQ_AUICigB&biw=2261&bih=1105

those power supplies that look like a wort on your wall

I've only got an old multi meter that might not be too accurate but tests ok on the battery. Ok on the 240v. But only milli volts on the transformers out. But like I said lights up the 35w globe ok.
So do I need to get a different type of transformer. I didn't realise these switch on and off for load.

Yup, you either need a dummy load, or a better suited PSU.
you are better off getting a PSU better suited to the loads (mA) instead of the 2+Amps of the down light.

 

[2cranky]

https://www.google.com.au/search?q=...PHUAhWKnZQKHQOsDVkQ_AUICigB&biw=2261&bih=1105

those power supplies that look like a wort on your wall




Yup, you either need a dummy load, or a better suited PSU.
you are better off getting a PSU better suited to the loads (mA) instead of the 2+Amps of the down light.

Ok I get it now.
Trick will be to get one that can fit inside the T box.

 

[2cranky]

Would a couple of these work?
https://www.jaycar.com.au/12-6v-ct-150ma-1-9va-centre-tapped-transformer-type-2851/p/MM2006

 

[Maheel]

you could try wiring in the 12v globe as well as the LED strip to see if that will then "turn on" the transformer.

just for shits and giggles to see if it will work....