ChargerAndControl

This page gives implementation details of the (recommended) combination of the ChargerController and Circuit 5a, shown in ChargingCircuits.

1. IMPLEMENTATION

The proposed combination is very simple. Both circuits should share a common ground and the same (stabilised) 6V positive voltage supply. Then the Input line of the ChargerController has to be connected to the +3.57V max positive battery output terminal of Circuit 5a and the Trickle control line of Circuit 5a has to be connected to the Output terminal of the ChargerController.

2. PCB LAYOUT

This combined circuit can be mounted on a PCB as small as 45x25 mm (not shown). This is adequate to be installed into a (relatively large) 6V adapter or into a small enclosure somewhere across the cable from the adapter to the AgVr3 serial-cable battery charger plug.

It can be also be mounted on a bit larger (40x50 mm) mounting board but with a more flat profile, so as to fit into the standard AgVr3 cradle. A possible layout for this version is shown below. In order to bring the 6V and Gnd lines of the wall power adapter into the cradle you could hack the serial cable positive battery line so as to use the plug on the back of the serial connector. Another, more recommended possibility is to install a female plug in the cradle to connect the adapter directly to the circuit.

Note that the circuit (the LM317 in particular) does dissipate a significant amount of heat. So a number of (small) ventilation holes are needed; mainly on the dome-like part at the back of the cradle. Note also that the geometry of the cradle is quite irregular and a significant dose of ingenuity is needed to actually get the PCB, cables and connector adequately accommodated into the scarce space available.

                  FRONT VIEW                           BACK VIEW