This is an idea that I started in the suggestions subforum, but I've managed to get it working to the point that the idea might be useful to somebody else. Basically, this is the opposite of Tinear's BOB. Instead of an addon that boosts 3.7V up to 5V, this regulates 7.4V down to 5V. It is a very simple device that anybody with basic soldering skills could make.
All I did was take a AP1084 regulator (the TO252 package fits perfectly) and wire it up inside a gutted 901 atty tube. The wiring diagram is shown in the attached image.
The only tricky bit was finding the right material to attach the regulator to the inside of the tube. All linear regulators work by converting any "extra" voltage to heat, and that heat must be rejected somehow or the device will overheat. If the regulator was just left as-is, it would overheat and shut down in about 10 sec. This is made more difficult in this case because the heat transfer pad on the back of the regulator is also the voltage output, so it must be electrically insulated from the tube itself. Almost by accident I found this stuff. It's meant for fixing pipes and other metal parts, but the fact that it contains metal particles means it conducts heat fairly well, yet it is somehow electrically non-conductive. However it works, it does work. I got a stick at my local Home Depot for less than $5.
The only problem with my prototype is that I stupidly used 22ga solid core wire, which doesn't flex very well. The result is that I can't press the atty connector all the way into the tube. There's enough room, but the wires just won't bend enough to allow it. I'm going to hunt for some more flexible wire tomorrow and take some pictures as I build another one.
So what is this useful for? Well, it will turn almost any mod into a 5V mod with the right batteries. Nearly all 18650 mods will fit two 18350s, or two 16340s, or at the very least, two 15270s - all of which are available in 3.7V versions. Even a small 14500 mod can take two 3.7V 14250s. This can turn any of those into 5V mods. I've been testing the RIT on my indulgence with two 18350s in the extended tube, and it works great. Under a 3ohm load, the regulator runs at a steady 4.87V, which ain't bad. The heat and vapor production compared to one 3.7V 18350 or 18650 battery like night and day. The carto I'm using starts hissing the instant you hit the button, and it delivers a huge cloud of hot, flavorful vapor.
True, LR attys produce somewhat comparable results, but they'r expensive and don't last very long. Plus, if you use cartos, there isn't really an LR option. This will give you 5V on any atty or carto with a mod you already have. For about $9 worth of parts (plus a blown atty and some batteries), this is a pretty cool addon that is not too tough to make.
All I did was take a AP1084 regulator (the TO252 package fits perfectly) and wire it up inside a gutted 901 atty tube. The wiring diagram is shown in the attached image.
The only tricky bit was finding the right material to attach the regulator to the inside of the tube. All linear regulators work by converting any "extra" voltage to heat, and that heat must be rejected somehow or the device will overheat. If the regulator was just left as-is, it would overheat and shut down in about 10 sec. This is made more difficult in this case because the heat transfer pad on the back of the regulator is also the voltage output, so it must be electrically insulated from the tube itself. Almost by accident I found this stuff. It's meant for fixing pipes and other metal parts, but the fact that it contains metal particles means it conducts heat fairly well, yet it is somehow electrically non-conductive. However it works, it does work. I got a stick at my local Home Depot for less than $5.
The only problem with my prototype is that I stupidly used 22ga solid core wire, which doesn't flex very well. The result is that I can't press the atty connector all the way into the tube. There's enough room, but the wires just won't bend enough to allow it. I'm going to hunt for some more flexible wire tomorrow and take some pictures as I build another one.
So what is this useful for? Well, it will turn almost any mod into a 5V mod with the right batteries. Nearly all 18650 mods will fit two 18350s, or two 16340s, or at the very least, two 15270s - all of which are available in 3.7V versions. Even a small 14500 mod can take two 3.7V 14250s. This can turn any of those into 5V mods. I've been testing the RIT on my indulgence with two 18350s in the extended tube, and it works great. Under a 3ohm load, the regulator runs at a steady 4.87V, which ain't bad. The heat and vapor production compared to one 3.7V 18350 or 18650 battery like night and day. The carto I'm using starts hissing the instant you hit the button, and it delivers a huge cloud of hot, flavorful vapor.
True, LR attys produce somewhat comparable results, but they'r expensive and don't last very long. Plus, if you use cartos, there isn't really an LR option. This will give you 5V on any atty or carto with a mod you already have. For about $9 worth of parts (plus a blown atty and some batteries), this is a pretty cool addon that is not too tough to make.
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If you are using the tube as a ground & both connectors are press fitted into the tube, why solder a ground wire to either of them? If I'm reading this right, the bottom connector is the Vin, the top connector is Vout, & ground is the tube which the regulator(ground), & both connectors are pressing against?
