Tech 21 · Utility

Midi Mouse

9V · ≥100 mA supply · maker

Tech 21 Midi Mouse power requirements

9V DC · centre negative · needs a supply of at least 100mA
also runs on a 9V battery · from the maker
“Utilizes standard 9V alkaline battery (not included). … Power consumption of LED display: approx. 15mA. •USE DC VOLTAGE POWER SUPPLY ONLY! … 9V DC regulated or unregulated, 100mA minimum; 2.1mm female plug, center negative (-).” source
Checked 2026-10-14

120.65 × 95.25 × 50.8 mm (4.75 × 3.75 × 2.00 in)

Width × depth × height, from the manufacturer.

Each has an output that can power it, checked against its published figure. Plan the whole board to see what runs everything.