Not-so-minimalist Pit-Box (Mark 2)

Here is the Pit-Box with completed electrics. Some additional tubing will be added for the specific tools and parts I'll be using to pit. The case is a cheap blow-moulded tool box available for $10 or so from a hardware shop. This tool-box has the advantage that the lip of the cavity is curled inwards - this helps prevent contents from spilling out when the box is shaken or even tipped over.

The front panel shows the banana sockets for the glow leads. These connectors are sufficiently rated for typical glowplug current without degrading. I use two different types of glowplug connector and leads (socket type for conventional plugs and clip type for Nelson plugs in F2D, so being able to remove/change them is helpful. The bottom socket is a conventional plug-pack socket for charging.

Here's the conventional ampmeter for indicating a good glowplug connection and being able to detect a flooded engine (cold plug filament causes amps to go higher). This has been bolted to the "flanges" on the tool-box. These flanges have been flattened out by heating under hot water and allowing it to cool in its new shape.

The internal wiring is for both the connection of the battery leads through the ammeter to the banana sockets, as well as the charging wiring from the connector to the battery. See below for more info on the charging circuit. The battery cell is a Hawker Cyclon 2V 2.5Ah unit, which works out to a perfect 1.5V at the plug using a 2 metre heavy gauge plug-clip lead (HiFi speaker wire).

The charger is a cheap 3V 1.5Amp regulated plug-pack originally designed for a Nintendo Game-boy and currently available for around $5 at Dick Smith or Tandy Electronics. The usual plug on the plug-pack's lead is replaced by one which matches the new socket on the pit-box (again from Dick Smith). Internally, the pit-box is wired up with the charging connector being connected to the battery. However, there are two 1 amp IN4001 (1 amp) rectifiers wired in parallel (to carry ~2 amps) connected between the positive terminal of the charge socket and the battery. The rectifiers reduce the regulated 3V (actually more like 3.3V) down to about 2.5V for the battery (the recommended constant voltage for charging).