Extra battery / 12v charging cable...meh...
I've got a box with a couple of good sized LiPo's in it, a 5v regulator, and 4 USB ports for charging...whatever...
But, I don't have a borescope
External Charger disassembly & detail
I have disassembled my FLIR E4 external charger to establish the quality of the design.
The rubber coated case is held together with a single screw under the ID label at the bottom of the charger. The base is a combination of metal and rubber. Construction is good and looks like it will last. The soldering is not the best I have seen and the excess flux has not been removed from the manually soldered micro USB connector. The unit is made in Malaysia.
I can advise that it is a standard 3 contact (NTC) Li-Ion charger design as will be seen below:
The main components contained within the charger are as follows (along with the common ID where known)
1. 1L4001 = Linear LTC4001 Battery management IC. 2A charger with Timer & NTC sense input.
2. MNAB ZC5 = T.I. LMC555 - Yes the venerable 555 (CMOS version).
3. UL46 = USBLC6-4 TVS diode array for USB2.
4. PZ = Not known but possibly BZB84-B33 Zener diodes
5. G3A = Diode
The data sheet for the charge manager (LTC4001) is attached. This details all that is needed to build your own charger, or to understand the FLIR design. The battery contains only an NTC thermistor of value 10K Ohms. No other 'management' is contained in the battery pack. It will have a protection circuit for the cell though.
The input connector for power is the same awful micro USB type as on the Ex, but at least it does not need to be unplugged often. A micro USB car charger may be used to produce a car charging pod for those on the move. The LTC4001 is tolerant of current limited power supplies.
For those wondering, the 555 timer just provides the low frequency drive to make the blue LEDs flash during charging.
Note the charging contacts. They look like they belong on a Canon Li-Ion battery charger. It may be possible to convert such a charger with relative ease but it may need its protection timer adjusted to take account of the Ex battery capacity.
The metal moulding in the bottom of the charger is a heat dissipator plate that is sinking heat from the LTC4001 via the PCB ground-plane. Not the most efficient design but it does not get very warm so appears adequate.
Lens materials and Close-up lenses
I recommend that a ZnSe Bi-convex lens is purchased for the purpose. These lenses are available cheaply from China and are made for the CO2 laser cutter market....
I purchased my lenses from here:
http://www.ebay.co.uk/itm/ZnSe-GaAs-Focal-Lens-for-10-6um-Co2-Laser-Engraver-Cutting-Machine-12-25mm-1-4-/321078811086?pt=LH_DefaultDomain_0&var=&hash=item4ac1c9d9ce
UPDATE: Georges80 has produced the STL files for 3D printing a lens holder to the E4.
My lens adapters are also ABS and there are two ways that the ZnSe lens may be held in place. Some users secure it with a thin bead on NON ACIDIC adhesive. Acid cure glues are a no-no with ZnSe ! Others have used a soldering iron to slightly melt the edges of the lens holder to create 'claws' like those used to retain gems in jewellery.
My lens adapters are also ABS and there are two ways that the ZnSe lens may be held in place. Some users secure it with a thin bead on NON ACIDIC adhesive. Acid cure glues are a no-no with ZnSe ! Others have used a soldering iron to slightly melt the edges of the lens holder to create 'claws' like those used to retain gems in jewellery.With the 3D printed lens holder designs you can find on this forum, there is no need to fix the lens.
The Chinese CO2 laser cutter lenses you can get from ebay just clip in nicely and firmly, so no risk of glue damage.
3d printers aren't "precision" instruments
So, you will get different results with different printers (and/or phase of the moon). Remember that the lens holder I designed was to specifically handle the lens I had on hand (via ebay) AND to be printed with the makerbot at work. I tweaked things to make it fit nicely - but no guarantee that all prints from my files will create a 'perfect' fit...
My main goal was a good friction fit in the E4 and to play it safe with the lens opening so that worse case a touch with a soldering iron would fix the lens in place. Since I printed with PLA it is easy to melt the plastic with a soldering iron that is only at 70 - 80C.
cheers,
george.
Close-up lens - Bi-Convex Vs Plano-Convex
@Sparky,
I am no expert in optics but can offer some comment....