SteveH, batteries connected in SERIES add the voltage of each battery to the load, but the current capability remains the same. Three C-cells in series will deliver 4.5 volts, but can still only deliver about 100 milliamperes.
You could connect a power supply that can deliver 1,000 amps, but the coin sorter will only draw what it needs to run. So if the 700 milliamp unit didn’t work, try one a lot bigger. You have to get the voltage right, but the amp capability of the power supply is not critical, as long as it is big enough.
