Can a Ultra PoE switch power devices with only a 12V or 24V input?
Feb 20, 2022
A Ultra PoE switch is designed to deliver power over Ethernet (PoE) according to established standards, typically at 48V DC or higher, depending on the PoE type (e.g., PoE, PoE+, PoE++). Whether a Ultra PoE switch can power devices that operate on 12V or 24V directly depends on the device's internal power handling capabilities or the presence of a suitable PoE splitter. Here’s a detailed explanation:
1. Standard PoE Power Delivery
Typical Output Voltage: A standard PoE or Ultra PoE switch provides power at 48V DC or higher, with PoE++ delivering even up to 54V DC. This voltage is standardized to ensure compatibility with a wide range of network devices like IP cameras, VoIP phones, and wireless access points.
Direct Device Compatibility: Most network devices designed for PoE have internal circuitry that steps down the incoming 48V DC to the required operating voltage, typically 5V, 12V, or 24V, without any external adapter. However, devices that are not PoE-capable and specifically operate on 12V or 24V will need additional support to use PoE power.
2. Using PoE Splitters for Lower Voltage Devices
PoE Splitters: To power a 12V or 24V device with a PoE switch, a PoE splitter can be used. The splitter takes the 48V DC PoE input from the switch and converts it to the specific voltage required by the device, such as 12V or 24V.
Function: The splitter separates power and data, delivering the correct voltage and providing an Ethernet data connection to the non-PoE device.
Installation: The splitter is connected between the PoE switch and the device, with the Ethernet cable from the switch supplying both power and data to the splitter. The splitter then outputs a lower voltage (12V or 24V) to the device.
3. Internal Voltage Conversion in Devices
Built-in Voltage Conversion: Some high-end devices, particularly those used in industrial or outdoor settings, come equipped with built-in voltage converters that can accept 48V DC input and internally step it down to 12V or 24V. These devices can be directly powered by a PoE switch without additional equipment.
Device Requirements: It’s important to check the specifications of the device to confirm if it has a built-in voltage regulator. If the device requires only 12V or 24V and lacks this feature, a splitter or a dedicated power adapter is necessary.
4. Ultra PoE Switch Capabilities
Enhanced Power Output: The term “Ultra” in a Ultra PoE switch typically refers to the enhanced power output capabilities per port (e.g., supporting higher wattages for PoE++ or proprietary higher output). This feature does not imply that the switch can directly output voltages like 12V or 24V; it means the switch can provide more power to devices that need it at the standard PoE voltage.
Applications in Powering Devices: While a Ultra PoE switch can power high-demand devices like PTZ cameras or large displays at 48V DC and above, devices specifically requiring 12V or 24V will need a voltage converter or splitter unless they have built-in conversion capabilities.
5. Voltage and Power Ratings
Wattage Considerations: The total wattage output from a Ultra PoE switch must be considered when powering high-consumption devices via splitters. For example, if a device needs 24V at 1A (24W), the PoE switch must supply enough wattage at 48V to match this demand after conversion. Typically, a PoE++ port delivering 60W or 100W will suffice for most medium- to high-power devices after voltage conversion.
Conversion Efficiency: Voltage conversion involves some energy loss, so the actual power drawn from the PoE switch may be higher than the device’s nominal power requirement. For instance, a 90% efficient splitter means that a 24W device will draw approximately 26.6W from the switch.
6. Practical Example
Use Case: Consider a scenario where a transportation system requires powering surveillance cameras or other monitoring devices that operate at 24V but do not have built-in PoE support.
Solution: A PoE splitter would be connected to the Ethernet cable from the Ultra PoE switch. The splitter converts the 48V DC from the switch to 24V and delivers it to the device while maintaining data communication through the Ethernet line.
Summary of Ultra PoE Switch and 12V/24V Device Compatibility
Aspect
Ultra PoE Switch
Standard Voltage Output
Typically 48V DC or higher
Direct Compatibility
Not directly compatible with 12V or 24V devices
Using PoE Splitters
Required for converting 48V to 12V/24V for devices
Built-in Device Conversion
Some devices can internally convert 48V to 12V/24V
Application
Ideal for powering high-wattage devices; splitters extend compatibility
Conclusion
A Ultra PoE switch can effectively power 12V or 24V devices when used with a PoE splitter or if the device itself has an internal voltage converter. The switch’s primary role is to provide a higher power output at the standard PoE voltage, which is especially beneficial in applications requiring long-distance or high-power connectivity. The addition of splitters or converters allows non-PoE devices to be seamlessly integrated into a PoE-based network.
LEER MÁS