What if you want to use a replacement LED lamp in your existing fluorescent fixture, but you’re concerned about the limited lifetime of the ballast? After all, few fluorescent ballasts can match the lifetime of an LED lamp. If that’s the case, consider the Intellitube lamp from Energy Focus, which can work with either a T8 ballast, or in a direct-wired, no-ballast fixture; after the ballast dies, have the old ballast pulled out and the fixture re-wired to a retrofit.
The Intellitube lamp is available in a 13W, 15W, and 18W versions at 3500K, 4000K, and 5000K — I tried the 13W, 3500K version.
Ballasted and unballasted from the same lamp
In my ballasted T8 fixture, the two Intellitubes drew 33W or 16.5W, coming on instantly with no flicker. Next, I tried the same lamps in a re-wired fixture with the ballast removed and the ac power connected to one end of the lamp. The lamps came on after a little over a second delay, with no flickering. (I don’t like any perceivable delay in turn-on, but I know it’s not a problem for many people.They consumed 25.6W, or 12.8W each, at a power factor of .95.
The light quality is fine, with a CRI of 83 and R9=12; R12=70:
Taken with the the MK350 spectrometer using MoreSpectra software
Inside the Intellitube
What’s inside? The Intellitube has a very sturdy enclosure:
The slot in the middle of the white plastic diffuser is where the LED pc board slides in, with the power electronics board below it. The bottom part — the aluminum heat sink — is quite large. (And hollow — the dark looks solid, but is just a shadow.)
The lamp has separate pc boards for the power electronics and the LEDs:
The red arrow points to a small finned heat sink that is glued over an IC. When the heat sink is removed, it reveals an SOP-8 package that seems to read BP2328A, which may be an LED driver IC from Regency Semiconductors. This IC has an internal 600V power MOSFET.
The spec sheet for the IC mentions its use in T8 LED lamps, but makes no mention of any designs for handling both ballasted and non-ballasted lamps. This is the first dual-use LED tube lamp I’ve tried, and it performs very nicely. As I say, I prefer no turn-on delay, but it’s not a deal-breaker for many people.
The single-sided LED board has 120 LEDs, each measuring 3.42mm x 2.84mm. I don’t know the make — any ideas? UPDATE: The LED looks like this HonliTronic SMD LED 2835.
EnergyFocus has an interesting version of the lamp called the “Intellitube – Buy American II” which was developed for their Navy contracts. This is the same as the standard Intellitube, but assembled completely in the US at the company’s Cleveland facility. It costs $26 (compared to the $23 price of the Intellitube) with the additional $3 because of the higher manufacturing costs in the US. The company says it has sold over 365,000 tube lamps to the Navy to date.
The Intellitube lamps (both regular and “Buy American”) are currently available for purchase, but you’ll need to contact Energy Focus directly. Starting in early Q4 you’ll be able to buy it on Amazon.