I have tested a DETA LED lighting electronic transformer. This is the one that bunnings sell. What is labelled as a constant voltage transformer is NOT a constant voltage transformer. In fact its no better than the Halogen lighting transformer voltage output. Comparing this to the Phillips ET-S 15W shows that the phillips version is a constant voltage and spot on.
The Phillips works with any number of LED MR16 lights up to the maximum wattage and holds its output voltage very well. The DETA version appears to be false advertising
Welcome to the Bunnings Workshop community @ThePredator. It's great to have you join us and many thanks for your feedback.
I will pass this information the information provided on to our Merchandise team to look into further. We appreciate you bringing this to our attention.
We would be more than happy to return the item with a refund or exchange. Please let me know if you needed any help facilitating this.
Many thanks once again.
I've checked this a bit more and I think the higher than expected AC voltage may be due to the switching frequency of the electronic transformer. I'm in the process of selling and moving and all my bench test equipment is packed away so I'm only using a cheap Klein and Jaycar pair of multimeters to progress most of my rewiring. The main factor in all this is what's in the LED lamp being used. I assume for the price I paid for it, that it would be a bridge rectifier followed by a smoothing capacitor and if the DC peak voltage at this point is too high, the capacitor and other components in the lamp will fail in a shorter time frame. There are other factors but this was one of my main concerns,
@ThePredator I assume this is the unit you are complaining about.
The output of the Deta transformer is chopped DC and will produce erronous readings on most digital multimeters.
These units are built to a price and I would expect the Phillips ET-S 15W to be much better engineered in comparison (and a little more expensive).
Not sure about MR16 LED bulbs, but I strongly suspect they have no smoothing capacitor, just an internal bridge rectifier to ensure compatibility between electronic transformers that produce quasi DC, and legacy iron transformers with 12v AC output.
My personal opinion is that the Deta transformer will probably be OK but if budget will allow, use the Phillips ET-S 15W instead.