According to this, which appears to be the same unit.........
http://www.ebay.com.au/itm/10W-30W-50W-100W-LED-SMD-Chip-Bulb-Bead-LED-Driver-Transformer-High-Power-Supply-/162045933474?var=&hash=item25bab0b7a2:m:mrAkcjQIpzv6_W3UHOODO7A
Quote ...." Changes in constant output current depend on...