I currently have 5 x 20W halogen bulbs attached to two AC 12V rails, and an AC transformer (105VA).
I'd like to replace existing five bulbs with five LEDs, e.g. these: 7.5W (update: 12V AC) (Equivalent halogen 43W).
My initial understanding (also supported by this question) was that the required power for such setup would be 7.5W * 5 = 37.5W, and therefore the existing transformer would work fine. However, the seller's website has this manual which basically states that in my calculations I need to use equivalent halogen power (i.e. 43W) rather than 7.5W. That would mean that the existing transformer wouldn't be sufficient.
I struggle to understand why equivalent halogen power should be used here instead of simply the bulb's power. Can anyone advise on this please?