I use a D4 for work. And regularly use it at “medium/high” levels, where the temp control keeps regulating. And when I’m done working I like being able to touch my light, not burn my fingers
Yes i did lose the insulating washers, the washers insulate the top layer of mcpcb from the head of the screws, but, the threads of the screws can still connect the top and bottom layers of the mcpcb??
Maukka…
In another thread I mentioned how the driver seems to be acting as a current limiting device. Though in theory a FET driver shouldn’t behave like that. Kiriba-ru questioned that.
Sounds like your screws may have eroded and worn through the top layer of the MPCB causing a short. Some options:
Option 1: Try rotating the MPCB 90 degrees. The screws would then go in the holes previously used by the optic. Those screw holes are presumably not eroded so hopefully you should not get a short.
Option 2: Omit the screws. The first run Emisar D4 actually did not have any screws holding the MPCB on. All you had was pressure from the optic and bezel holding the star down. The main purpose of the screws is so that when you tighten the bezel the star doesn’t rotate and possible break the solder on the driver wires. That said, many triples, quads, and single emitter lights work just fine without any screws at all, and the D4 is one of them. Since the screw are causing your light to malfunction, I suggest omitting them.
Option 3: get a replacement star. Any 24mm standard quad star will fit. You can buy one from Moutain Electronics and reflow the emitters onto it.
Thanks for your answer. But I don’t understand what do you mean by “eroded”, because the screws holes are all metal so the screws can connect the top and bottom layers of mcpcb easily and no need anything to be eroded?
The copper substrate of the MCPCB is electrically separate from the PCB traces that power the led. When the screw wears through the red layer it may connect the traces to the body causing a short
I got a PM telling me that a resistor is a standard way of slowing down a FET. Quick search:
Yeah, it is. So it seems that a FET used this way is actually a high-ripple regulator.
But…I tried to use your scope results to actually measure the ripple. Now that I think about it, not knowing your sensor’s response curve it was a broken idea. But I got something I don’t understand - and I’d like to.
I see that at fairly low duty the peaks reach about 1.5V. But then they get lower and Turbo voltage is below 0.5V. So…I would interpret it as D4 being much brighter in peaks than with a FET wide open. I don’t believe that’s the case.
Any explanation?
When properly assembled, the screws do not cause a short.
However, in your case, you are getting a short. One possibility is that by screwing and unscrewing your screws the bottom of the screw heads ground through the layer of paint on the top of the MPCB under the screw heads. If that grinding went through into a trace then there could be a short. I do not know offhand if the MPCB used in the D4 has traces near the holes, but if it does, that could explain why you are getting a short.
So ive been scouring this thread debating on the typical emitter choice and for a while I had planned on a 3k SST20 because I want this specifically for late night walks and candle mode (once I flash Anduril) but the green levels at low current are making me rethink my choices.
I dont really want to spring for the XPL-HI 5D if I dont need to, but green tints are a hard stop.
I kinda feel like an ass, but I just ordered a D4 with Anduril flashed and 3k/4k tint mixing. I have the capability of flashing an ATTinyXX, but I really dont want to mess with beating the driver out.
Hank will do the D4 or D1 with Anduril flashed ? If so, I’m probably going to get another D4 or a D1. I flashed my D4S to Anduril, but haven’t got the skills to do the solder work on my D4.
I finally relented and bought an Emisar D4. got the XPL 5K. Question, if I were to ask nicely, you think Hank would flash Anduril before shipping? Or I’ll just have to figure it out myself on my own?
Anybody in the San Francisco bay area know how?
I like the idea of a stepped option rather than just ramping.
Probably depends on how long ago you ordered it. Send an email, today, so he'll likely read it when he wakes up. He's been very responsive with me but we started the conversation before I ordered.