I’m curious about that driver. It’s being sold as a 10W 12V driver but it looks like the 4115 is rated at up to 30Vin (and those rectifier diodes are rated at 40V and 1A) so is this really a 30W (30V @ 1A) driver in disguise?
The ones I bought from Lightake had a 35V electrolytic cap, but they stopped selling them. The latest ones seem to have a 25V cap.
That small ceramic cap (rated voltage is unknown) is connected from the +Vin pin to the mosfet switch output. It is not shown in any of the PT4115E documentation and is not used on any of the smaller form factor M16 drivers… it can probably be removed.
Theoretically it is a 30+ watt driver, but in the real world is limited to 20-25W. They come with the current sense resistors set to 750 mA (not 1 amp). I modded one for the rated 1.2A output and it quickly went into thermal shutdown. If you parallel the sense resistors with a 1 ohm resistor, you get around 950 mA out, and it seems to work fine.
You need to check the voltage rating of the electrolytic cap on the board. I have seen boards with 35V and 25V caps. Some of the boards have a small ceramic cap of unknown voltage rating that is connected between the +Vin and SW pin (mostfet switch output) of the chip… it can probably be removed.
If you are driving the board with DC power in (and are careful not to reverse the power supply polarity) you can bypass those 4 diodes in the input bridge rectifier circuit and get better efficiency out of the board (those diodes eat around 1W at 1 amp). It also gives you around 1V more headroom on the input voltage requirement.
I used the reservation service to order three of them. I’m probably going to use two on AC power, and one for toying around with battery powered. 12V DC drivers for these 3x3 1W LED modules are easy to find for a few dollars. I’ve seen the enclosure before, there’s a fair amount of room in the back compartment, however, I’m not sure there’s enough for 3x18650 cells. If they do not fit, I’ll probably go with some kind of Li-Poly pack, once I have exact dimensions.
i’ve been thinking again about modding one for battery use.
it’s my father’s birthday tomorrow so he will get one of these that i have changed to swedish cord. i will ask him if he would like to have it modded for portable use.
My thoughts goes like this:
change led and install driver somewhere.
I would use 2x14500 batteries in separate battery holders.
the driver is for single batteries, and I would use 2 switches; one for on/off(charging) and one for selecting battery A or battery B.
When switched off you could connect the charger to usb, and charge either battery A or B, depending on the battery switch.
i’m a bit worried that there might be some parasitic drain if i combine off state with charging state. Does anyone know anything about that?
it’s very late here, so maybe i don’t make much sense. but do you think this would be a good mod for this light?
i guess i thought it would be safer treating them as separate cells, and also you know when you’ve used half of the available power.
if i bought protected trustfire flames 14500, would it be as safe to just use them in parallel instead of the switch-based setup? both while running the light, and when charging the batteries