rhd
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This builds on some of the discussions from driver threads re: combining LM317 ICs to achieve higher currents.
Didn't have much luck with the LM317s on two li-ion cells, powering a 445. But I've found that combining THREE of the lower drop-out LM1117s, along with the balancing resistor design anselm found, worked quite well!
Here's the circuit I settled on:
The 2 Ohm resistors would suggest a total output of ~1800 mA. Ultimately the design resulted in a consistent 1650 mA. I'm chalking the shortfall up to the balancing resistors.
At ~600mA per Lm1117, we're running them under their suggested current limit. They don't seem to get particularly hot.
Here's a shot of the guts all stuffed in the guidesman host. I used a stiff piece of copper, wound in a single circle around the inside of the host (soldered to the walls) to retrieve the (-) from the case.
And here it is next to Pocket Mini Chrome, my "Guerrilla Blue" build (1,000mA), and my "Indie Bullet" which although 1,600mA at the time of writing that thread, has now been rewired with the same 1,000 mA driver as my Guerrilla Blue.
You can tell in the photo, but it's even more obvious in real life that this build is noticeably higher powered than the other three.
Hope someone enjoys this thread
Didn't have much luck with the LM317s on two li-ion cells, powering a 445. But I've found that combining THREE of the lower drop-out LM1117s, along with the balancing resistor design anselm found, worked quite well!
Here's the circuit I settled on:
The 2 Ohm resistors would suggest a total output of ~1800 mA. Ultimately the design resulted in a consistent 1650 mA. I'm chalking the shortfall up to the balancing resistors.
At ~600mA per Lm1117, we're running them under their suggested current limit. They don't seem to get particularly hot.
Here's a shot of the guts all stuffed in the guidesman host. I used a stiff piece of copper, wound in a single circle around the inside of the host (soldered to the walls) to retrieve the (-) from the case.
And here it is next to Pocket Mini Chrome, my "Guerrilla Blue" build (1,000mA), and my "Indie Bullet" which although 1,600mA at the time of writing that thread, has now been rewired with the same 1,000 mA driver as my Guerrilla Blue.
You can tell in the photo, but it's even more obvious in real life that this build is noticeably higher powered than the other three.
Hope someone enjoys this thread