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Gonna change the oil
"Bill McKee" wrote in message .net... "Eisboch" wrote in message ... wrote in message ups.com... First version, otherwise why use 6 resistors instead of one single lower ohmage one of higher power. I was trying to roughly calculate the power requirements. You said 600 ohm resistors, correct? The voltage drop on the LED will be minimal when forward biased or "on", so each branch must be about .02 amps, times six equals .12 amps, so the power must be about 12v times .12 or about 1.4 watts. Probably a bit more when you factor in the LED drop, whatever it is. Significantly less than a regular light bulb! Eisboch Most LED's are in the 400mw range. Does that include the new, high powered ones? The are being used on trucks for brake lights, turn signals and other places to replace bulbs. They are incredibly bright. Maybe the brightness is due to optics being used, like a Fresnel lens or something. Eisboch |
Gonna change the oil
"Bill McKee" wrote in message .net... "Eisboch" wrote in message ... wrote in message ups.com... First version, otherwise why use 6 resistors instead of one single lower ohmage one of higher power. I was trying to roughly calculate the power requirements. You said 600 ohm resistors, correct? The voltage drop on the LED will be minimal when forward biased or "on", so each branch must be about .02 amps, times six equals .12 amps, so the power must be about 12v times .12 or about 1.4 watts. Probably a bit more when you factor in the LED drop, whatever it is. Significantly less than a regular light bulb! Eisboch Most LED's are in the 400mw range. How about the standard 12v bulb used for anchor lights? |
Gonna change the oil
OK, my recollection from a web site about LED use said to figure a
voltage drop of 3.4 volts for the white ultrabrights leaving about a 9 volt drop for the resistor. At 600 ohms, this gives about .015 amp through each resistor and LED. Yes, the correct resistor wattage is less than 1/4 watt but I hate blowing resistorswhen odd things happen and space saving is not a consideration here. Radio Shack had nothing even as alrge as 1/4 watt less than 1000 ohms. |
Gonna change the oil
" JimH" wrote in message ... "Bill McKee" wrote in message .net... "Eisboch" wrote in message ... wrote in message ups.com... First version, otherwise why use 6 resistors instead of one single lower ohmage one of higher power. I was trying to roughly calculate the power requirements. You said 600 ohm resistors, correct? The voltage drop on the LED will be minimal when forward biased or "on", so each branch must be about .02 amps, times six equals .12 amps, so the power must be about 12v times .12 or about 1.4 watts. Probably a bit more when you factor in the LED drop, whatever it is. Significantly less than a regular light bulb! Eisboch Most LED's are in the 400mw range. How about the standard 12v bulb used for anchor lights? I don't know what their wattage rating typically is. My guess would be somewhere between 10 - 20 watts, given that they are required to be seen, what, 2 miles away at night? Eisboch |
Gonna change the oil
For the sake of comparison, a normal anchor light is 12 watts. These
LEDs are seriously bright, ordered em from Digi-Key. |
Gonna change the oil
wrote in message oups.com... OK, my recollection from a web site about LED use said to figure a voltage drop of 3.4 volts for the white ultrabrights leaving about a 9 volt drop for the resistor. At 600 ohms, this gives about .015 amp through each resistor and LED. Yes, the correct resistor wattage is less than 1/4 watt but I hate blowing resistorswhen odd things happen and space saving is not a consideration here. Radio Shack had nothing even as alrge as 1/4 watt less than 1000 ohms. That's what I really dislike about the "new" Radio Shack. I suspect once their inventory of discrete components are gone, you won't be able to buy *any* resistors, capacitors or anything there. Eisboch |
Gonna change the oil
I'll admit, half the stuff I try doesnt work but i suspect this will.
Anothetr thing I am trying is to wire my solar panel as a way to turn off the anchor light at night. I got the idea from a web site I saw so I lay no claim to it. They connect a NC relay across the solar panel. When it generates power, it powers the relay (30 mWatt) which turns off the anchor light. Of course I'll incorporate a switch to turn off the entire thing, relay incluided. Radio Shack did have the relay. |
Gonna change the oil
wrote in message oups.com... I'll admit, half the stuff I try doesnt work but i suspect this will. Anothetr thing I am trying is to wire my solar panel as a way to turn off the anchor light at night. I got the idea from a web site I saw so I lay no claim to it. They connect a NC relay across the solar panel. When it generates power, it powers the relay (30 mWatt) which turns off the anchor light. Of course I'll incorporate a switch to turn off the entire thing, relay incluided. Radio Shack did have the relay. You have a great attitude. People get smart not by always knowing what works, but rather what doesn't. You never know until you try. Eisboch |
Gonna change the oil
"Eisboch" wrote in message ... " JimH" wrote in message ... "Bill McKee" wrote in message .net... "Eisboch" wrote in message ... wrote in message ups.com... First version, otherwise why use 6 resistors instead of one single lower ohmage one of higher power. I was trying to roughly calculate the power requirements. You said 600 ohm resistors, correct? The voltage drop on the LED will be minimal when forward biased or "on", so each branch must be about .02 amps, times six equals .12 amps, so the power must be about 12v times .12 or about 1.4 watts. Probably a bit more when you factor in the LED drop, whatever it is. Significantly less than a regular light bulb! Eisboch Most LED's are in the 400mw range. How about the standard 12v bulb used for anchor lights? I don't know what their wattage rating typically is. My guess would be somewhere between 10 - 20 watts, given that they are required to be seen, what, 2 miles away at night? Eisboch What is the benefit for a boater on the hook overnight besides having a brighter anchor light? Is there a significant less draw on the house battery over a 10 hour period? |
Gonna change the oil
Less than half the draw on the house battery.
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