I own both the Energizer Aluminum Pen LED Flashlight (PLED23AE) and the Dorcy 41-1218 2AAA 5MM LED Pen Light. The following is my side-by-side comparison.
In terms of mechanical construction, the Energizer and Dorcy pen lights are very similar. They are both approximately 5.5" long by 0.5" diameter. Their tail caps and on/off switches both have the same flimsy feeling (I have no problems with either version). But they are very different when it comes to LED brightness.
When powered by two fresh alkaline AAA cells (2x 1.6V), the Energizer pen light generates a wide, powerful beam. The Dorcy pen light is not as bright, but at least it is still useable for indoor illumination. However, the biggest difference is when powered by two rechargeable NiMH cells (2x 1.25V). The light output of Energizer drops to about 50%, while the Dorcy becomes so dim that it is basically useless. (See my Customer Images for brightness comparisons).
The reason becomes clear when I disassembled both pen lights. The Energizer contains a power module to boost lower battery voltage to drive its LED. That's why it can continue to shine even when the combined battery voltage falls to 1V. The Dorcy, on the other hand, has no power regulator at all. Its LED is driven directly by the two AAA cells, and so the current is very sensitive to battery voltage. At 3.1-3.2V (two fresh alkaline cells), the LED current is around 30mA, so its light is acceptable. When the battery voltage decreases to 2.6V, the LED current drops to only 2mA, and its light is barely visible.
This is not to say that the Energizer pen light is perfect. One problem is that its power consumption is not well regulated. At 3V battery voltage, its input power is about 360mW. But at 2.5V its power drops to just 180mW. That explains why when using NiMH cells, the light is only half as bright as when using fresh alkaline cells. In contrast, the Rayovac BRSLEDPEN-B LED Pen Light is able to maintain the same brightness between alkaline and NiMH cells.
On the package of the Energizer pen light it claims "Super bright LED" and "Over 100-hour run time". This is very misleading, because it is physically impossible to power a "Super bright" LED for 100 hours using just 2 AAA cells. The LED may burn brightly in the beginning when the batteries are fresh. But as the battery voltage drops lower, the power consumption (and hence brightness) drops quickly. So only the first 10-20 hour may be marginally called 'Super Bright'. Nevertheless, this is still much better than the traditional incandescent pen light (which can hardly sustain 2 hours of useable light), so I should not complain too much.
(8 customers reviews)
Customers Rating=4.0 / 5.0
More Detail For Energizer Aluminum Pen LED Flashlight Two AAA Batteries PLED23AE
- Bright lifetime Nichia LED light.
- Durable aluminum body stands up to falls and rough handling.
- Fits in your pocket.
- Push-button switch for one-handed operation.
- Clips to pocket, tool bag or briefcase.
ไม่มีความคิดเห็น:
แสดงความคิดเห็น