Assembling the Handy Board, Part 6

For this assembly sequence, collect the following parts:

• BAT1 (9.6 volt AA nicad battery pack)
• ENCL1 (LMB model 402 plastic enclosure)
• F1 (RUE250 PolySwitch© resettable fuse)
• four self-tapping screws
  

Fuse Installation

Assembly

Testing and Debugging

Battery Installation

CAUTION: BATTERY PACKS ARE OFTEN DELIVERED FULLY OR PARTIALLY CHARGED, AND EXTREME CARE MUST BE TAKEN NOT TO SHORT THE TWO BATTERY TERMINALS TOGETHER.

In practice, this means that you must not let the two exposed wire ends inadvertently come into contact with each other, nor should you cut through pre-attached wires in the same snip.

The reason for this is that Nickel Cadmium batteries are capable of driving huge amounts of current through a short circuit, far more than common household Alkaline batteries. Shorting out Nicad batteries, even for a brief interval, CAN POSE A SERIOUS EXPLOSION AND FIRE HAZARD.

Assembly

If the pack comes with pre-soldered wires, individually clip the wires to approximately three to four inches in length. Do not yet strip off the insulation at the ends away from the battery.

Position the battery pack in the lower half of the LMB enclosure (the half with the taps for screws). Route the wires around the screw posts as indicated in the diagram.

Make sure the Handy Board's main power switch is turned off.

Strip about 1/4 inch of the insulation off of the red (positive terminal) wire. Twist the wire strands together, and insert into the round battery hole (marked with a + on the component side). Insert the wire from the bottom of the Handy Board and solder from the top.

Now do the black negative terminal wire in the same fashion, soldering it into the square hole (marked with a - on the component side). Be careful not to let the exposed black wire touch any point of the Handy Board other than the hole in which it is mounted. This could apply the 9.6v battery voltage to components that are only rated for 5v, causing those components to be destroyed.

If you have a hot glue gun, add a dab of hot glue to the battery wires on the underside of the board.

Testing

Now plug the adapter into the Interface/Charger Board, and connect to the Handy Board with the telephone cable. Put the Charge Rate switch on the I/C Board into the NORMAL position. The yellow CHARGE LED on the Interface/Charger Board should now light. Flip the Charge Rate switch to ZAP!!, and the CHARGE LED will turn off.

Battery charging tips:

• In Normal charge mode, the Handy Board will fully charge its battery in 10 to 15 hours (assuming its power is turned off).
• In Zap charge mode, the battery will charge in about three hours, after which it will become warm and should be placed in Normal charge. Do not leave the Handy Board on Zap charge indefinitely---it will cause the battery to fail prematurely.
• The charge jack on the Handy Board itself is equivalent to the Normal charge mode.

Debugging

Final Assembly

Note that only half of the plastic enclosure is used in the final mounting (holding the battery pack underneath the Handy Board).

If the Handy Board is to be used with LEGO parts, glue four flat LEGO pieces to the underside of the case. Make sure to first mount the LEGO pieces on a baseplate so they are installed at valid LEGO spacings! Cyanoacrylate glues (e.g., Crazy Glue©) are recommended for affixing LEGO pieces to the Handy Board case.