Six floodlights were bought in Leroy Merlin: Wolta 50 W, 30 W, 20 W, 10 W, Volpe 50 W 3000K, Volpe 10 W 3000K. In addition, I bought Osram 30W 3000K floodlight in Metro.
I will not go into detail about the design features of the projectors and will go straight to the results of my measurements.
All tested floodlights have a very high level of light ripple (ripple rate 91-100%). This pulsation is clearly visible and can lead to eye fatigue, headaches and aggravation of nervous diseases. Moreover, such light is just very visually unpleasant and annoying.
All Wolta and VOLPE floodlights are built on linear drivers. Because of this, the brightness of their light changes from the slightest changes in the voltage in the network and drops dramatically with reduced voltage. I measured the luminous flux at a stabilized voltage of 230 V, and when on a 220 V network, the brightness of Volpe floodlights drops by 5%. The Wolta's brightness drops by 5% when the voltage drops from 230 to 202-212 V. The OSRAM projector uses an unusual driver. It behaves like a pulse, but it stabilizes the voltage in a very small range - already at 199V the brightness drops by 5%. Wolta floodlights have an operating voltage range of 180-240V. In fact, at 180V, the brightness of the 10W Wolta WFL-10W / 06W model drops by almost half (45%).
The Volpe and Wolta 10, 20 and 30 W packages have a color rendering index of "> 80". The measured color rendering index of these spotlights was 71-74. Only OSRAM has a measured color rendering index of more than 80.
The declared power of OSRAM and Wolta floodlights is close to the measured one, and the luminous flux is even higher than the declared one by 8-19%. At VOLPE, the measured power turned out to be 22-25% lower than the declared one, the luminous flux of the ten-watt model is 13% lower than the declared one, and in the 50-watt model it is lower than the declared one by as much as 33%. The efficiency of OSRAM and VOLPE is low - 77-78 lm / W, while the Wolta is much higher - 92-95 lm / W.
Only two floodlights (OSRAM and VOLPE 10 W) work correctly with switches that have an indicator (do not light up or flash when such a switch is off). All other spotlights glow dimly when such a switch is turned off.
Luminous flux, color temperature and color rendering index were measured using a two-meter integrating sphere and an Instrument Systems CAS 140 CT spectrometer, power consumption and power factor (Power Factor) with a Robiton PM2 instrument, ripple coefficient with an Uprtek MK350D instrument. The minimum voltage level at which the luminous flux decreased by no more than 5% of the nominal was measured using a Lamptest-1 device and a Suntek TDGC2-0.5 LATR instrument.
Unfortunately, all of the tested floodlights have very high light ripple, so I cannot recommend any of them for purchase.
PS Test results of all spotlights on Lamptest .
© 2020, Alexey Nadezhin