Print PDF
Favorite
Email
Step 5Conclusion
The previous information was in error due to a crappy multimeter.
After consultation with an engineer friend. I found out that the initial resistor " R1 " value is at 180 Ohms and that the remaining eight resistors "R2 thru R9" each have a value at 460 Ohms.
He also advised to measure voltage across each LED and voltage across all the LEDs in each branch circuit. With that information, the total resistance for each branch circuit was calculated. For simplicity, each branch will be called, Branch 1, Branch2, etc.
Branch 1 had a total resistance of 960 Ohms. Branches 2 thru 9 each had a total resistance of 860 Ohms. The total resistance for Branches 2 thru 9 is 860/8 = 107.5 Ohms. The total resistance for the entire board is
(107.5 x 960) / (107.5 + 960) = 96.67 Ohms.
The total Voltage for the board is 20.7 Volts. To obtain the total power usage I use this formula.
Power = Voltage Squared / Total equivalent Resistance
Therefore
20.7 x 20.7 / 96.67 =
428.49 / 96.67=
4.4 Watts per strip
Each fixture has four strips @ 4.4 Watts each. This equals 17.6 Watts per fixture. This is just less than the original fluorescent ones that these replaced.
However, the LED fixtures have some key advantages. First, they require no real parts that need to be replaced periodically, i.e. tubes, ballast, etc. Second, they do not make noise, the fluorescent ones hummed a bit. Third, these can be dimmed, sort of. Dimming is accomplished in a stepped mode by switching off each strip individually to obtain a required light level (this is a feature to be added in the future).
After consultation with an engineer friend. I found out that the initial resistor " R1 " value is at 180 Ohms and that the remaining eight resistors "R2 thru R9" each have a value at 460 Ohms.
He also advised to measure voltage across each LED and voltage across all the LEDs in each branch circuit. With that information, the total resistance for each branch circuit was calculated. For simplicity, each branch will be called, Branch 1, Branch2, etc.
Branch 1 had a total resistance of 960 Ohms. Branches 2 thru 9 each had a total resistance of 860 Ohms. The total resistance for Branches 2 thru 9 is 860/8 = 107.5 Ohms. The total resistance for the entire board is
(107.5 x 960) / (107.5 + 960) = 96.67 Ohms.
The total Voltage for the board is 20.7 Volts. To obtain the total power usage I use this formula.
Power = Voltage Squared / Total equivalent Resistance
Therefore
20.7 x 20.7 / 96.67 =
428.49 / 96.67=
4.4 Watts per strip
Each fixture has four strips @ 4.4 Watts each. This equals 17.6 Watts per fixture. This is just less than the original fluorescent ones that these replaced.
However, the LED fixtures have some key advantages. First, they require no real parts that need to be replaced periodically, i.e. tubes, ballast, etc. Second, they do not make noise, the fluorescent ones hummed a bit. Third, these can be dimmed, sort of. Dimming is accomplished in a stepped mode by switching off each strip individually to obtain a required light level (this is a feature to be added in the future).
| « Previous Step | Download PDFView All Steps | Next Step » |
 |
Add Comment
|
