Low voltage heater
Posted: Sun Jun 02, 2013 10:25 pm
Hello,
I have a little project to build, but have virtually no knowledge of electronics, although I can handle a soldering iron, and many years ago, managed to follow instructions and successfully build a working transistor radio from a circuit diagram and individual components. I decided to join this forum in the hope that someone can help me with advice and a suitable circuit diagram I can work to.
Since my childhood over 40 years ago, I have been a keen amateur astronomer. I have recently discovered the convenience of using a green laser pointer attached and aligned with my telescope to help find objects easily in the night sky. I am aware of the effects on aircraft and possible eye damage, but mitigate these by only using the beam for several seconds at a time, which is all it takes to find an object, after which it remains off.
The laser works great in warm weather, since the operating temperature is specified to be above +10 degrees centigrade. The bulk of my astronomical observing is done in the colder months when night time temperatures are usually well below 10C and often below zero. At these temperatures the laser will work fine for several minutes whilst dimming until invisible. Using Lithium batteries (2 x AAA) seems to slightly prolong the life of the beam but not by much. Once the beam has failed, I can reactivate it by removing it and warming it in my hands for a few minutes, but almost as soon as I have fitted it back into its bracket and accurately aligned it again with the screws, the beam has dimmed and is virtually useless.
My laser pen is approximately 150mm long by 14mm diameter, more than half the length holds the 2 AAA batteries. I propose to carefully wrap a coil of Nichrome wire around the business end of the laser pen, on top of a thin layer of electrical insulation and then to insulate the outside of the coil. I need a simple controllable circuit to run off a small battery pack, possibly two or four AA batteries or whatever is recommended so I can vary the power in case of overheating, but keep the laser warm enough to function as and when required for a few hours. So I really need to be able to raise and maintain its temperature by up to a maximum of say 20 degrees C.
For your information, the Nichrome wire I propose to purchase from Mindsets Online is a 10 meter coil costing only a couple of pounds, and specified as 0.1mm thick, with a resistance of 1 ohm per centimetre.
Is this a viable idea or are there better ways to do this?
Any help, comments and advice on this would be very welcome, since I really don't have a clue what I am doing.
Cheers,
Pete.
I have a little project to build, but have virtually no knowledge of electronics, although I can handle a soldering iron, and many years ago, managed to follow instructions and successfully build a working transistor radio from a circuit diagram and individual components. I decided to join this forum in the hope that someone can help me with advice and a suitable circuit diagram I can work to.
Since my childhood over 40 years ago, I have been a keen amateur astronomer. I have recently discovered the convenience of using a green laser pointer attached and aligned with my telescope to help find objects easily in the night sky. I am aware of the effects on aircraft and possible eye damage, but mitigate these by only using the beam for several seconds at a time, which is all it takes to find an object, after which it remains off.
The laser works great in warm weather, since the operating temperature is specified to be above +10 degrees centigrade. The bulk of my astronomical observing is done in the colder months when night time temperatures are usually well below 10C and often below zero. At these temperatures the laser will work fine for several minutes whilst dimming until invisible. Using Lithium batteries (2 x AAA) seems to slightly prolong the life of the beam but not by much. Once the beam has failed, I can reactivate it by removing it and warming it in my hands for a few minutes, but almost as soon as I have fitted it back into its bracket and accurately aligned it again with the screws, the beam has dimmed and is virtually useless.
My laser pen is approximately 150mm long by 14mm diameter, more than half the length holds the 2 AAA batteries. I propose to carefully wrap a coil of Nichrome wire around the business end of the laser pen, on top of a thin layer of electrical insulation and then to insulate the outside of the coil. I need a simple controllable circuit to run off a small battery pack, possibly two or four AA batteries or whatever is recommended so I can vary the power in case of overheating, but keep the laser warm enough to function as and when required for a few hours. So I really need to be able to raise and maintain its temperature by up to a maximum of say 20 degrees C.
For your information, the Nichrome wire I propose to purchase from Mindsets Online is a 10 meter coil costing only a couple of pounds, and specified as 0.1mm thick, with a resistance of 1 ohm per centimetre.
Is this a viable idea or are there better ways to do this?
Any help, comments and advice on this would be very welcome, since I really don't have a clue what I am doing.
Cheers,
Pete.
