Joule Thief

[Pirate88179]

Tyson:

Thank you very much.  I keep finding new uses for these flash circuits, ha ha.  This one really zapped me so I know it is a good one.

Bill

[NickZ]

  Pirate Bill
  It is amazing what those little transformers and cap combinations can output from a 1 volt battery. I was also surprised when I got zapped by one of those. Hopefully will not happen again. 
  Each one of the D cells has almost 10 times more storage capacity than a normal rechargeable AA or AAA. So, your joule thief lamp conversion should run a good long while.
  The best way to do it is to make the circuit able to be recharged, by just plugging in a wall adapter, and charging the batteries. Or from a small solar panel, or a from a couple of garden light type solar cells. Those alkaline D cells can be recharged real well, especially at low input amps so they do not blow up or leak.  The garden light solar cells output 4v, and about 30 mA.
Now some of those lanterns are being sold that have a small solar panel on the top.

  Anyways, nice job Bill.  Thanks for sharing

[Pirate88179]

Nick:

Thanks.  Yes, these little circuits have bit me probably about 20 times or so now.  You would think I would learn right?  I don't really use rechargeable bats not because I don't like them, mainly because I get so many free "dead" batteries from friends that I have enough to run all of my lights for over a year.  But yes, on that lantern mod, that would be a nice feature....so would the solar cell.  So many of those cheap garden lights are around now that getting a few cells from those would be free and do the job nicely i would think.  This was just a quick project I did for my friend who is in the Navy and gave me the lantern on Friday.  I delivered it to him tonight so, not a bad turnaround for something I have not done before.

I have a little Harbor Freight lantern ($5) I got a few years ago that has that nice conical reflector and 27 leds.  It has a hand crank generator on it.  I have always wanted to add solar and a supercap to that and now, I am thinkiing, if I can light that 2500 lumen LED module I ordered, that would be perfect for that reflector.  So many projects, so little time and money, ha ha.

Keep up the work that you are doing.

Bill

[MileHigh]

Bill:

With the cost of solar panels much cheaper now, let me muse about a project for fun.  I don't know if it is affordable because I don't know how much supercaps cost.

You put some solar panels outside or on your roof and they charge a big supercap bank.  You could easily program an Arduino as a controller.  The setup would be something like solar panels connected to a "Bedini" pulse charger that charges a supercap bank.  The Arduino switches the pulse charger on and off and would measure the cap bank voltage to keep it "topped off."

Assume the big supercap bank is in a weatherproof box or in a garage.  Then you wire DC power into a few rooms.  You use fast-blow fuses at the cap bank source and in the rooms, etc.  There is a real danger for fire without the fuses.  Wires could easily get white hot then molten without fuses.

So, you have some JT lamps for the living room and the bedroom.  I bet you could find an LED TV that's a decent size that runs off a 12-volt input.  So that's no problem, you could also have a powerful enough DC to DC converter that outputs 12 volts to power your TV while it sucks energy from the supercap bank, which might be at a much lower voltage.

Finally, if your supercap bank starts to run low during the evening the Arduino could let out a little warning beep to let you know about the impending shutdown.

I just realized that you could probably get a 12-volt big-screen TV at an RV center.

Anyway, you might not be able to run a big-screen TV.  An evening where you read and listen to the radio might be doable though.  Having "sockets" to power all of your JT lamps then makes them truly homey.  You never have to change the batteries, etc.

To do it, it's just a number crunching exercise.  How much energy do you need during the evening?  Based on that how big a supercap bank, how many panels, etc.

It's kind of a nice idea though.  Your evening at home is powered by a bank of supercaps, and they automatically charge the next morning so by the end of the day the supercaps are topped off and ready for the evening.

MileHigh

[MileHigh]

There is a little trick that you could do for the Arduino so that it could run for a few years off of a few alkaline D-cells.  The monitoring process for the supercap bank voltage would only have to be done say once every five seconds.  You could program the Arduino where it runs off a slow clock, and only "wakes up" to check the battery voltage every five seconds.  Otherwise it is effectively in suspended animation waiting for the programmable timer inside the chip to tell it to wake up.

So the Arduino power to control the setup is minuscule, so tiny that you can connect it to some ordinary batteries and only have to check it once a year.