constant current

We've been running three of the below Philips GU5.3 5W 76954500 spotlights in our ceiling for the past 5 years: https://www.amazon.co.uk/gp/product/B00KTUZCB8/ They replaced 50W 12V halogen spotlights, each with their own transformer. We kept the existing 20+ year old toroidal transformers in...