Power Supply Selection Guidelines

Keep the following requirements in mind when selecting your power supply.

Power source, input voltage and Frequency (AC/DC)
Number of DC devices to be powered
Voltage requirements of DC devices
Wattage/Amperage of each DC device required
Maximum/Peak draw of each DC device
Physical space available and mounting requirements
Check for applicable safety approvals for the location and application

The conversion of Volts to Watts is governed by the equation Watts = Amps x Volts.
Note: there are 1000 milliamps (mA) in 1 amp.

While most power supplies allow operation at 100% of rated capacity, it is recommended that an extra 30% be factored in. This allows the power supply to run cooler, more efficient and extends the life.

For example:

Device #1 requires 24 Vdc and draws 1 Amp [24Vdc X 1A = 24 Watts]
Device #2 requires 24 Vdc and draws 500mA [24Vdc x (500/1000)A = 12 Watts]
Total wattage required is (24 + 12 watts) x 1.3 = 46.8 Watts
Round up to the nearest 10 watts would be 50 watts.

Therefore, you would select a power supply rated at 50 watts and outputs 24 volts DC.