Greetings saber people! I am new here and am currently working on sabers for myself and my daugthers. One of the sabers will just be a plain LED string blade with a switch and a 18650 LiIon battery. To charge the battery without removing it from the saber I came up with this:
I have made a tiny USB charger board based on the LTC4054 chip with programmable charge current up to 800mA.
The board is 6x7mm and can be soldered on the back end of a micro USB connector with solder pads or with wires from a USB connection. The whole thing will then be about 15mm long including the connector and the board with components are smaller that the USB connector so it fits through the connector mounting hole. It can be mounted on the end of the saber through a 2.5x7mm slice. The board connects to the battery and a charge indicator LED.
I will be using a flat chrome 12mm panel toggle switch with LED ligth mathcing the saber that will be used as charge indicator. This makes the build wery simple with 4 components: Battery, LED blade, USB connector with charger and switch with indicator light.
Picures, links and schematics will follow. I have ordered a lot of the tiny PCB's that I can share with you for self cost. I can also solder up some boards if anyone are interested.
USB Connector:
10pcs/lot Micro USB 5pin Female Socket Connector Welding Type for Tail ChargingChange IC:
http://cds.linear.com/docs/en/datasheet/405442xf.pdfSwitch w/LED light:
12V 12mm LED Power Push Button Switch Momentary Latching Waterproof Metal | eBayUSB Charger Schematics:
http://i.imgur.com/Qtapv8u.jpgCharge current can be changed with the value of R1. LED current is changed with R2. 220ohm will give app. 10mA.
Prototype soldered directly to USB connector:
http://i.imgur.com/zaoji5l.jpgThe board will look like this, with names for the connections on the back side:
http://i.imgur.com/937dC3S.jpgUnpainted saber with holes for mounting switch and USB connector:
http://i.imgur.com/rgVFg7M.jpgThe connector is not fully inserted, it will be flush with the rear end. This saber is made as a toy for my 8 year old daughter and is scaled down to 75% of the size.