Review: CoolIT Systems USB Beverage Chiller
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Reviewed by Ryan McLaughlin on 01/31/2006
Editors' rating: 0.0/10
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  • wildconcern

    It’s important to note that this device draws almost double the 0.5A spec on typical USB ports. Quite often this 0.5A is shared amongst several ports. So even if you’re lucky enough not to take your port down, you may eliminate the ability to add any other USB devices. Buyer beware is all I’m saying.

    The Travel Insider did a pretty extensive test of the power demand this unit requires. While they admit their test computer didn’t suffer any ill effects over 24 hours, there is a risk of overburdening the 5V supply. You can read about it here…

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  • RocketRobin__

    From the USB 2.0 specifications Over-current Protection:
    The host and all self powered hubs must impliment over-current protection for safety reasons, and the hub must have a way to detect the over-current condition and report it to the USB software. Should the aggregate current drawn by a downstream facing set of ports exceed a preset value, the over-current protection circuit removes or reduces power from all downstream facing ports. The over-current condition is reported to the Host Controller, as described in section 11.12.5. The preset value cannot exceed 5.0A and must be above the maximum allowable port current such that transient currents (e.g., during power up or dynamic attach or reconfiguration) do not trip the over-current protector. If an over-current condition occurs on any port, subsequent operation of the USB is not guaranteed, and once the condition is removed, it may be necessary to reinitialize the bus as would be done on power-up. The over-current limiting mechanism must be resettable without user mechanical intervention. Polymeric PTCs and solid-state switches are examples of methods, which can be used for over-current limiting.

    This device draws no where near USB 2.0 specified over-current limit of five amps. Even users of antiquated Macs, Xboxes and quality PCs that are fully USB 1.0 compatible will have no issues with this device.
    This USB beverage chiller was designed as an accessory for quality computing devices. It was NOT designed for use with computing devices that have a lesser value than the accessory.

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    • wildconcern

      The USB 2.0 spec states, “cannot exceed 5.0A” for “safety reasons”, meaning it could actually be less. The over-current refers to the “aggregate current”, not the per-port current. The CoolIt Chiller uses only one Type A port, defined as follows:

      USB 2.0 spec, 7.2.1 states, “A unit load is defined to be 100 mA. The number of unit loads a device can draw is an absolute maximum, not an average over time. A device may be either low-power at one unit load or high-power, consuming up to five unit loads.” Further, Type A contacts are typically 1.5A max, with the max wire size (20AWG) as 1-3A bundled (depends on jacket).

      That being said, given this is a high current device with no communication electronics… it is best to refer to the USB Battery Charging Spec, Rev 1.1

      “3.5 Charging Current Limits – In order for a Portable Device to force a Dedicated Charging Port into current limit mode, a Portable Device is allowed to attempt to draw a current that is greater than 1.5A, and which can be as high as 1.8A max.”

      That assumes it’s even a dedicated charging port to begin with. Granted, high enough for this device, but not exactly the 5A you suggest What does “quality computing device” mean anyway? USB power alone hardly defines overall quality.

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  • Sempron Gamer