In this topic I’ll rely on the tools to change / reassess the wires and gauges used to feed the system. The current status of the connections is a total mess. The reason is to be found in the stratification of the updates. Each time I was adding something, I basically brought a wire from the power supply to the component, most of the times with a margin in length. Gauge wise the situation is also suboptimal; different gauges, shields are used. This setup leads to un-even tensions between the components, which therefore may suffer to operate nominally. I figured it out by measuring the tension at the LDG, which was barely 4V. Even if it is all but exciting, I therefore chose to rewire the power supply to each and every component. Possibly, in the future, I’ll carry out a similar task for the LEDs lines.
The plan
The main idea is to create a main branch, based on a thicker wire, AWG18 to feed a bus just behind the monitor, hence relatively close to many of the subsystems to provide the most coherent tension levels possible to all the systems.
From the bus, to each component the same wire type is used, same gauge and same shield.
The benefit of this approach is that a more efficient cable. management is provided, moreover tensions offset between components is less likely.
The picture below show the schematic of the connections. As Mainboard and ICP are very close, they only are fed by one cable, similarly the LDG, Speedbrake and TWA are on a satellite, hence are fed by a common wire.
The power needs of the boards are limited at most by the use of LEDs, no other considerable load is connected directly to the devices. Nevertheless, a rather big wire, AWG18 was used for the principal bus carrier, while the subs are powered by a more conventional AWG24.
The loads are connected to the ATX (PIN 4 and 5), therefore the nominal 5V is guaranteed. A different set up could rely on different 5V sources to spread the current more evenly throughout the ATX connector, yet again, considering the modest power needs, the cleaner, single site configuration, was used.
The component which is numbered 1 · 8 and 1 · 4, are multiplier connections, which are really handy ways to provide a multiplexer. They come in different sizes and for different gauges (mostly for bigger gauges), an example is shown in the figure below.
When smaller gauges are needed 30 to 26, I simply created a trivial PCB, you can find it in the repository, which allow short cutting 9 + 9 signals. One may solder the wires directly, although I find more convenient adding 2.54 mm (0.1 in) pins and rely on Duponts connections.
Final remarks
As always it is important to ensure that all the boards share a common GND, so don’t forget about this important remark.
giovannimedici 