finished the head, well almost, still need to glue a thermal switch, waiting for a thermal epoxy to come in, but there is something strange going on, i wanted to see how bright it is from 1 18650 in dd, so i hooked up protected panasonic, to 6x xpg3 wired in parallel, (btw since i had to order new triples that had a thicker star, i had to completely redesign the head, i eliminated the need for outside glass\window .
so after hooking up 1 cell. the leds blinked and went out, it happened every time i connected the cell, so at first i thought the leds are sorted, prbly pinched a wire or something, so i checked continuity, there is none, so leds aren’t shorted,. so i hooked my dmm, and realized the pcb brakes the circuit on overcurrent. so i wanted to measure how much current 6 xpg3 pull, my dmm went OL, so it was over 10A. so then i figured i’ll wire a driver now, so i wired several different liner drivers, and in all cases results were the same, OL, which can not really be true, no way a 4amc driver can pull over 10A from a cell, i did check several times if i did not wire them DD by mistake, i know it is physically impossible, so i think my dmm is lying. or it’s battery is low, and it gives faulty reading, will try a different one tonight, and will to replace battery first.
that aluminum tape covers a hole where thermal switch will go,
will sure do if i do not figure what is wrong tonight, i kinda can believe, that 6 xpg3 can pull enough current to trip a 18650 pcb, but 10+ amps draw with several different drivers is definitely not right.
that is what i thought at first, but no, continuity test showed no short. i hope it is my dmm that is the issue, will test tonight, i already borrowed another dmm, and have spare batteries.
leds do work, i run them off an unprotected cell and they light up and stay lit. protected cell however trips the pcb. but that i can believe, 6 leds, that are less than 3v, powered directly by a healthy cell that is at about 4v can pull over 6A which is what pcb in the cell is approx. rated at. but 10A with several different drivers, and cells, idk, some cells i tried cannot physically put out 10a.
the problem was my DMM’s battery, i replaced it and no more OL. on a half drained cell, or more, i had 4,5, at 3.7v under load, it took about 30-40min to get to 3v. since a poster before mentioned about temp, i ran leds to see how hot it’ll get, well it did not, it was pretty warm but not too hot. granted the cell was not fully charged, but i have no doubts even with fresh cell, 10-15W will not heat up the heatsink to a dangerous numbers. 9A however will, and pretty fast. so with no 9A driver no need for thermal switch,
originally i was gonna install 2 drivers, 4,5 and 9A. when the heatsink would get too hot a thermal switch would shut off either both drivers, or just 9A driver. even if both drivers would be off, i would still have white light in rgbw group, but only about 3W. or if i only wire 9A driver to the thermal switch, i’d have 4,5A. but now i’m thinking to abandon that plan, and instead use a driver that maxes out at 3.5A. i have drivers made by Quadrupel. they are D10 drivers, fet+1 iirc, with anduril UI. the driver fits under a 16mm switch boot just right, only few mm thick, has many different modes. has built in switch, all i need to do, is design and print a housing for the switch boot and a driver, and install it where i originally wanted to install a DT switch, so i will have 1 DT switch, and 1 pushbutton. which also has leds to light up the boot.
here is a pic i took while testing, caught a moment when current and voltage matched, lol