Well the title is misleading just a bit. The BD04 does have a reverse polarity protection circuit. However, it’s in the tail cap! errrrr…
I put a lot of work into this build. Payed attention to detail. I added four 7135 chips to the driver. I put in an xpl hi but I didn’t have a 16mm Noctigon so I swapped and reflowed the xpl to the 16mm and moved the nichia 219 over to the 20mm. I lapped the pill and emitter. I thermal greased the mcpcb and pill threads. I lubed every o-ring and all threads. I took apart the tail cap and added a 1mm rubber shim to the button to make it nice and tight. I took apart and put back the thing five times before I found the perfect shim thickness. I put a dialectic compound on all the contacts, and there are a lot of them because of the design with the tail cap charging.
Today I had it all together. Tested the beam and it looked great. I thought, “hey! Let’s check how many amps the driver is pulling!” I popped in an 18650 and grabbed my DMM. As soon as I touched the leads to the battery tube, i knew it was toast! Yep! I put the battery in the wrong way and POP goes the driver. But wait isn’t the bd04 supposed to have rpp? This is how I learned that the reverse polarity protection must be in the tail cap.
I know! Thanks for the sympathy. I will have to do some research to find out what parts blow when this is done. I’m thinking it is the mcu. I could change that out but there might be a special firmware that alows for the battery charging while the light is on. There’s not a lot of info on this light so this may be difficult.
Bummer. It happens though. Yesterday I connected 2S 18650 to a BLF A6 driver and it fried in about 1 second. I was supposed to put them in PARALLEL…. That driver was not functioning properly anyway so no big deal.
That’s the thing about these “neat ideas” in a light that are proprietary… you can’t just swap stuff out at will. I was just this morning looking at the BD02 with the charge port snapping onto the side e-switch clicky. I’d love to be able to make changes, but could I? I, like you, just don’t know.
I was thinking of getting it for my neighbor who just retired from 35 yrs as a cop. Be easy for him to snap the charge ring onto the switch and keep it topped up, much like the Stinger’s he’s so used to, but as I understand it the UI kinda sucks and it’s underpowered. No perfect Leatherman. sigh.
I hear what your saying. When the wife moves the silverware from the first drawer to the second because it’s closer to the dishwasher it means for the rest of my life I’ll be opening two drawers to get a spoon. But atleast it’s easier unload the disheasher.
Don’t get me wrong, I realy liked this light. I think the design is useful and advanced. I was able to mod it up to three amps, which for a zoomie, isn’t bad. I like that it has a charger without a charging port. The charging clip feels a little cheep, but it works well.
I just wish they would have thought to put the reverse protection in the head instead of the tail!
Do you think it would work if I transfered an attiny from a qlite? Idk if the firmware is sensitive to the charging circuit. Maybe I’ll just try it Do you know if there are any other components that may have been zapped other than the mcu?
I have seen Nanjg drivers (and other drivers that copied the Nanjg layout) that popped the protection diode like a fuse when given reverse polarity. Nothing else was damaged, a new diode fixed it.
Maybe it's just me, and everyone else knows the BD04 driver forwards and backwards from memory, but it might help to show some pictures of this thing. There may well be a protection diode on the driver.
yes I have diode test. ive never used it before-not sure what to make of the numbers? :–5 I can give it a test in an hour or so. Ill check with my meter and also jump over it as well.
thanks for helping!
One way measures .198 the other reads no connection. So I guess it’s toast. Do you know which diode I will need? Back when I put in an order to digikey for the stuff to flash my own drivers, I took the advice of someone on here to add a bunch of driver parts to the order. I skimmed through a bunch of threads and wrote down the values of common components and added them to my order. So, I think I will have the part, but I don’t remember which part it is. I’ve got three or four diodes to choose from. I’ll have to dig them out after lunch.
Verify it's bad first. Connect a temporary test LED, apply power, jumper the diode pins with tweezers. If it works when jumpered but stops when you let go, replace the diode and you're done. If it doesn't work either way it's the MCU.
Oh, by the way, have you checked that the LED still works?
Man, I do not have good luck with exotic drivers!
The led is still working so that’s not it. I reconnected the circuit to test as suggested. Jumping over the diode was unsuccessful. There is a .15 voltage drop across the diode and there is 3.9v supplied to VCC which makes me think the diode is still good.
One funny thing about the circuit is that I cannot find the negative path to the grounding ring. the negative battery terminal, which in this driver is the spring, is not connected to the grounding ring of the driver. It test as a connection of 2M ohm resistance. So I cannot see how the circuit is grounded. The only path that tests as continuous from the spring is the pad to R2. From R2 connects to R1and pin 7 then R1 connects to VCC. This is why there is voltage to VCC, its the only path to battery neg. But everything but r2 is ungrounded. I don’t get how this is working. Did I damage a grounding trace from spring to outer grounding ring? IDK? I’m sure I’m missing something obvious.
You can't measure continuity through a diode like from B+ straight to pin 8, even if the diode's not damaged. Same thing for measuring from pin 8 to ground - the only path to ground there is through the two resistors. Pin 7 to ground only has to go through one resistor (4.7K).
The difference is that the ground from the 4.7k is not continuous with ground to pin4/grounding ring/7135gnd.
The 4.7k has a path to batt neg, but nothing else on the board shares that connection. So the path from the bat neg to the main ground of the circuit is not there. Does that make sense?
Is that part of the charging circuit BS? Can you bypass all of that just to see if you can make the driver work?
Put B+ straight to the pad the LED+ wire solders to. Connect B- to the ground ring around the outside. See if light comes out. Add the other parts back to the circuit later.
I have been connecting straight to the driver, but I have not tried moving the neg lead from the spring to the grounding ring. If I do that r2 will no longer be grounded, but I can try it. I guess then I could try it with bat neg connected to both the grounding ring and the spring and see what happens… Poof! Pop! Sizzle Sizzle!
You have a normal driver there (101-AK), with other crap added to enable the charging circuit. You've already done step 1, make light come out of the LED. Next step is make the driver make light come out of the LED. Add the other parts back one at a time, changing the test setup as needed (I can't tell you anything about what goes where when it comes to the charging circuit parts), until it stops working.
Do you know if there are any other components that may have been zapped other than the mcu?
