How to Choose the Right High Wattage Power Supply

Jameco Electronics Power Buyer's Guide

There are three basic units in electricity: voltage measured in volts, current measured in amps and resistance measured in ohms. Power is measured in watts, which express the rate of energy conversion with respect to time. Basically, voltage (volts) multiplied by current (amps) equals watts.

The main duty of a power supply is to provide power to the connected load (devices). The more robust the application, the more power required and the higher the wattage you'll need from the power supply.

The first rule of thumb is that it's better to have more power than not enough. Without enough power, your devices would not be able to turn on at all. It is also not recommended to have the power supply run at 100% of its capacity. Although a 25 watt power supply can power devices requiring 25 watts, there is a chance it will shut down completely if random spikes in the load occur. This can cause components to overheat and break.

Basic terms of how to choose the right power supply.

High Wattage Power Supply
Mean Well High Wattage Power Supply

Running for sustained periods at full capacity also creates stress to the electronic components, increasing the potential for failure. Therefore, it is better to run a higher wattage unit at half capacity than a lower wattage unit at full capacity. We recommend leaving at least 10% to 20% headroom between what you need and the power supply's maximum rating.

There is no truth to the myth that a large wattage power supply will force too much power into your devices causing overheating and burnout. The power supply will only provide the needed wattage. For example, a device that needs 50 watts will only get 50 watts from a 250 watt supply, not the entire 250 watts.

The chart below describes the Mean Well high wattage power supplies that Jameco has available. Each family contains multiple power supplies with different wattages. The lowest and highest wattages per family are listed.

Mean Well Family Wattage Mean Well Family Wattage
RSP-500 297W-504W RSP-1000 720W-1008W
HEP-600 480W-604W SE-1000 750W-1000W
HRP-600 369W-648W RSP-1500 1200W-1536W
HRPG-600 396W-648W PSP-1500 1087W-1368W
PSP-600 400W-600W SE-1500 1500W-1502W
SE-600 597W-600W SPV-1500 1500W-1536W
RSP-750 500W-753W RPS-2000 1200W-1920W
SP-750 600W-750W RSP-3000 2400W-3000W

Beyond the total wattage, you'll have to select the right voltage as well. Too much or too little voltage can damage the device. Some devices may try to overcompensate for the lack of voltage by increasing current, but this can cause damage or in the case of powering a motor, it might simply overheat without providing the necessary torque.

It is typical for a high wattage power supply to require the use of a DIN connector. A DIN connector surrounds several types of cables that plug into an interface and connect devices. It is composed of multiple pins that are within a protective circular sheath.

Continuous power and peak power are a few additional factors to consider for a high wattage supply, though they can apply to any power supply. They are sometimes confused as being one in the same, but they actually represent different concepts.

DIN Connector
DIN Connector

Continuous power is the amount the power supply can deliver consistently to the load this is also known as maximum power. As an example, the continuous power of a 500 watt power supply is 500 watts. The peak power refers to the maximum power it can sustain for a short time, sometimes called peak surge power. Peak power always produces a higher value than continuous power, but it only refers to a very limited amount of time. It acts as a protection for the load spikes. The same 500 watt supply can have peak power of 1,500 watts for 5 seconds. This varies with each power supply but the information is usually found in the power supply's data sheet.

We hope we've been able to answer your questions regarding selecting a power supply with high wattage. For more information head to the Jameco Power Resource Center.