All PSU Base modules can be powered from a d.c. power supply, batteries or a USB mains plug (the type used for mobile phone charging).
All modules use 4mm connection leads which are available separately, if required. Four units will fit into a shallow Gratnells tray.
A mounted battery holder, for use as a power supply, which has 4 x 1.5V C size cell holders mounted on a plastic base, with 4mm sockets to allow tapped outputs at 1.5V, 3V, 4.5V or 6V. The base has been formed to raise the sockets clear of the work surface below, allowing 4mm plug leads to be fully inserted. Batteries not included.