How do I connect multiple drivers or controllers to a single power supply?


If you can provide the required power (see appropriate datasheets) to multiple drivers or controllers, the wiring is the only issue. There are two methods of connection: daisy chain and star connection.

While wiring the devices in series or in a chain (often referred to as daisy chain – see Figure 1) may be simple and use the shortest length of wire, it can cause many problems to the system. The first problem is low current and voltage. The amount of current and voltage input to the first device will be much larger than the amount in the last device at the end of the daisy chain. This may cause the driver or controller to not function properly or at all. Another issue is the added ground loops due to multiple paths to ground. There can be troubleshooting complications with daisy chained devices. If there is a problem at the beginning of the chain (bad wires or connections) the rest of the chain will be without power.

Figure 1: Daisy Chain

Wavelength recommends using star connections (see Figure 2). This ensures each device will have the same voltage and current inputs. Troubleshooting is made more simple with direct wiring from the device to the power supply. Ground loops will be minimized with the star connection. Wavelength also recommends using the same length wires (for each device), twisted wires, and the shortest wires possible for the lowest noise setup.

Figure 2: Star Connection