I’m a big fan of gadgets so when I saw that Vat19 had a USB device which would act as both a cup warmer and cooler I just had to try it!
Vat19 claims the device “Keep a beverage piping hot or cool as ice.” A bold claim for something which powers itself on the small amount of juice the USB bus can put out, but out of the box the device seemed well constructed, so I was optimistic.
First thoughts:
Unfortunately I noticed the first two flaws with the desktop appliance before I even plugged it in. First, there was no on/off switch anywhere on the unit which, while not tragic, would become a problem if your only free USB port is on the back of your system. Second, the switch to change from warming to cooling is on the back near where the cord exits. While neither of these flaws are tragic, both proved irritating.
In action:
I plugged the USB Beverage Warmer & Cooler into my free USB on my laptop and heard the fan on the unit spin up. Surprisingly the small fan made quite a bit of noise, considerably more than my Dell laptop, even more than most modern desktops.
Ignoring the noise I set the unit to warming mode and put my coffee on the unit. Now another problem… The heating/cooling element was too small for a normal sized coffee mug. A half hour later, with my mug straddling the heating element my coffee had cooled to its typical tepid.
For my next cup of the day I switched to a smaller mug which would fit on the heating plate and got somewhat better results. My coffee stayed warmer than usual, but still not warm enough to justify another device and the loss of desk space.
(Please ignore the small army of drinking birds in the background of the picture above. They are of no concern to you.)
Hoping for better results on the cooling side I unplugged the unit and let it cool to room temperature. After lunch I flipped the switch to cool and plugged it in. I was surprised at how quickly the plate cooled so I put my bar-style pint glass full of water on the plate. Half an hour later my water still seemed enjoyably cool, but was it cooler than without?
I decided to do a more scientific test of the cooling capabilities of the unit, so I got two cans of Coke out of my fridge and grabbed the trusty cooking thermometer. With one can on the cooler and the other on the desk (far enough away to not be heated by the exhaust from the cooler) I measured the temperature of each over a two hour interval.
With an ambient temp of 70 degrees F and a starting beverage temp of 39 here are my findings over the next two hours:
After 30 minutes, can on cooler = 50, can on desk = 50
After 1 hour, can on cooler = 57, can on desk = 57
After 1:30, can on cooler = 59, can on desk = 61
After 2:00, can on cooler = 60, can on desk = 63
After the full 2 hours I sipped from each Coke and could tell some difference, but again, not enough to justify another device on the desk.
Conclusions:
While I love the idea of a USB beverage warmer & cooler the current model from Vat19 falls short of both “piping hot” and “cool as ice”. While the price point of $24.95 is very reasonable the novelty quickly wore off and the many drawbacks doom this gadget to the junk drawer. Perhaps a future rendition will bring improved performance and flexibility, but for now there are better warmers to be had and the cooling effect is not enough to justify this unit.
may i know how to make it,circuit diagram or component inside
can u show us the circuit diagram?thanks