Led controllers - Page 1
Forum section: electronics / beginners

author: dieselmudder
author_rank: Newbie
timestamp: October 26, 2017, 12:02:48 am
content: I'll get right to the point, I got one of those cheap, LED tent lanterns, each click of the switch cycles it through modes, bright, medium, dim, strobe, off. Can the circuit board be modified to have dim and off only, or what should I search for to find a circuit board with only on, and off.I will say, I'm not totally green to electronics. I can solder, use a voltmeter, and understand basic dc electrical. I'm just not well versed in electronic circuitry. I'm not asking to be spoon fed answers, I'd like to be pointed in the right direction though.Sent from my SM-J727V using Tapatalk

author: Mr.B
author_rank: Unknown
timestamp: October 26, 2017, 12:13:34 am
content: Take it apart.Post a photo of the circuit board.This will give us a much better idea of the possibilities.However, my guess is this...It all depends upon how determined you are.The modes you describe are very common in portable LED lighting.This suggests that a dedicated, mass manufactured chip/micro is responsible for controlling it.If the chip is a micro, the chances of reprogramming it are very slim.If you can remove the chip and substitute some other control electronics you may have a chance.As I said above - we need to see it to provide more informed suggestions.

author: dieselmudder
author_rank: Newbie
timestamp: October 26, 2017, 02:32:31 am
content: Thanks, I'll try an get a picture tomorrow evening.Sent from my SM-J727V using Tapatalk

author: forrestc
author_rank: Unknown
timestamp: October 26, 2017, 02:47:33 am
content: Many of these have a small capacitor in them which provides voltage so the controller can remember what state it was in last.... if you remove the capacitor, or add some resistance across it, often the 'memory' will go away, which means you get whatever the 'default' mode is, usually either on dim or on full....I've taken to just adding a resistor across this capacitor which reduces the amount of hold time, which still permits the multiple modes - it just resets to the 'default' mode really quickly so leaving it off for more than a couple of seconds will reset it back to the original state. No more turning on in some random state. On the other hand, I'm pretty aggressive about not buying a multimode flashlight in the first place....

author: dieselmudder
author_rank: Newbie
timestamp: October 26, 2017, 09:45:56 pm
content: I presume as stated earlier, this is a mass produced, low cost circuit board. And assume it can be gotten in various configurations. It always comes on in high mode, and have to click through low, and strobe to get to off.Sent from my SM-J727V using Tapatalk

author: dnwheeler
author_rank: Regular Contributor
timestamp: October 26, 2017, 09:52:40 pm
content: Big Clive has dissected a few of these on his YouTube channel (search for "bigclivedotcom lantern"). They use a small, special-purpose chip to switch modes (that's why so many LED lights, lanterns, flashlights, etc. all have the same modes). You should also be very careful about recharging these things. Some will put the full mains voltage on the USB port when charged from a wall outlet.

author: dieselmudder
author_rank: Newbie
timestamp: October 26, 2017, 11:06:14 pm
content: Quote from: dnwheeler on October 26, 2017, 09:52:40 pmThanks. This one uses AA batteries. I'll look up his channel. I browsed Mousers website, to try an find variations of this board. But I don't really know what keywords to look for.Sent from my SM-J727V using Tapatalk

author: james_s
author_rank: Super Contributor
timestamp: October 27, 2017, 08:49:38 pm
content: I've seen some that used a small 8 pin microcontroller, it would be easy enough to replace it with an AVR, PIC or whatever you're comfortable dealing with. I've never been able to figure out why they all seem to have a completely useless flashing mode that you have to cycle through, all I can think is maybe the Chinese took the term "flashlight" too literally. I never once have wanted my flashlight, work light or lantern to be flashing.

author: forrestc
author_rank: Unknown
timestamp: October 28, 2017, 01:27:45 am
content: Quote from: james_s on October 27, 2017, 08:49:38 pmFeature creep at it's finest.More features = more things to tout about how great it is. Unfortunately in this case (like so many others), no one bothered to ask if most customers wanted it.