I often wondered what the purpose of PDAs were until I was recently bequeathed one. After several weeks of having it, I am unable to understand how I lived without it.
With a card, I can hold most of my frequently used music. I can write notes, and documents. All without having to find a pen and paper. Also, and more importantly, I will have these notes accessible later, and won't be searching for them.
I have found a number of freeware EE applications on the web. This makes my life definitely easier. When I have a moment between things, and out on the road, the games I have entered make the time pass quicker. In fact, I am even writing a novel on it during these moments, and before I go to bed.
In short, the PDA is an interactive piece of paper that is always with you. I don't think that these will go the way of the dodo. In fact, my only regret that my model is not also a cell phone. My next cellphone will definitely include a PDA.
Actually, my post covered that. As I stated, one or more LEDs in a socket. Depends on how many lightbulbs are in a room. Many light fixtures are for two or three light bulbs, and many rooms have more than one light fixture.
The resistor is the simplest manner of current limiting an LED. However, one may create a simple constant current source with a couple BJTs, or DC/DC synchronous buck converter for the cadilac solution. None of this justifies a $79 price tag, and all are available to the electronics hobbiest.
I most definitely know what you are talking about. I have spend a significant amount of time in the bush, and off grid. I have used kerosene lamps (Aladin), white gas lanterns, battery operated lamps, propane lamps, and natural gas lamps.
Of the total, I find that the kerosene lamps put out the most pleasant colour spectrum. I have several LED flashlights. They are perfect for an application such as this. You want light that is bright, and will allow the battery to last. However, they have a definite blue colour, and are painful to the eyes, much more so than a regular flashlight. In a flashlight, this is not necessarily a problem (few things look natural under a flashlight anyhow). However, in the home, it would not be the most beneficial. For the best spectrum inside the house, I would suggest the salt crystal lamps with a regular lightbulb inside. They are extremely restful on the eyes, and when the lightbulb heats the salt crystal, it produces negative hydrogen ions, which are beneficial to the air inside your home, and you as they destroy free radicals.
There are new varieties of white LEDs that do not have the blue tinge. However, no-one is using them for much of anything yet. I was talking with a friend about this, and came to the idea of simply cracking a lighbulb around the base, taking out the filament, and soldering one or more of these new white LEDs (with current limiting resistor). Then the glass could be reaffixed to the base. This is a cheap and effective solution that would require much less than $70.
Slashdot Mirror
I often wondered what the purpose of PDAs were until I was recently bequeathed one. After several weeks of having it, I am unable to understand how I lived without it.
With a card, I can hold most of my frequently used music. I can write notes, and documents. All without having to find a pen and paper. Also, and more importantly, I will have these notes accessible later, and won't be searching for them.
I have found a number of freeware EE applications on the web. This makes my life definitely easier. When I have a moment between things, and out on the road, the games I have entered make the time pass quicker. In fact, I am even writing a novel on it during these moments, and before I go to bed.
In short, the PDA is an interactive piece of paper that is always with you. I don't think that these will go the way of the dodo. In fact, my only regret that my model is not also a cell phone. My next cellphone will definitely include a PDA.
Actually, my post covered that. As I stated, one or more LEDs in a socket. Depends on how many lightbulbs are in a room. Many light fixtures are for two or three light bulbs, and many rooms have more than one light fixture.
The resistor is the simplest manner of current limiting an LED. However, one may create a simple constant current source with a couple BJTs, or DC/DC synchronous buck converter for the cadilac solution. None of this justifies a $79 price tag, and all are available to the electronics hobbiest.
I most definitely know what you are talking about. I have spend a significant amount of time in the bush, and off grid. I have used kerosene lamps (Aladin), white gas lanterns, battery operated lamps, propane lamps, and natural gas lamps.
Of the total, I find that the kerosene lamps put out the most pleasant colour spectrum. I have several LED flashlights. They are perfect for an application such as this. You want light that is bright, and will allow the battery to last. However, they have a definite blue colour, and are painful to the eyes, much more so than a regular flashlight. In a flashlight, this is not necessarily a problem (few things look natural under a flashlight anyhow). However, in the home, it would not be the most beneficial. For the best spectrum inside the house, I would suggest the salt crystal lamps with a regular lightbulb inside. They are extremely restful on the eyes, and when the lightbulb heats the salt crystal, it produces negative hydrogen ions, which are beneficial to the air inside your home, and you as they destroy free radicals.
There are new varieties of white LEDs that do not have the blue tinge. However, no-one is using them for much of anything yet. I was talking with a friend about this, and came to the idea of simply cracking a lighbulb around the base, taking out the filament, and soldering one or more of these new white LEDs (with current limiting resistor). Then the glass could be reaffixed to the base. This is a cheap and effective solution that would require much less than $70.