The design itself is quite straight forward with simple transistor driven relays to provide the isolated outputs.
The design was first tested on stripboard.
Construction on standard 0.1" stripboard was complicated by footprint of the selected 12V relay, this meant that an additional 1mm hold needed to be drilled in the prototype board. The hole was required in order to accommodate the central pole of the relays contacts.
The prototype appeared as below and functioned well during soak tests.
The design was then transferred onto PCB for manufacture.
The new board arrived and was populated for testing.
Tests concluded successfully on the new PCB.
Intended modifications for #2
1- Modify Transistor placement footprint in order to facilitate assembly.