This quick and easy evaporative cooler might be just the thing the next time the air conditioning goes on the fritz. [Stephen] saw an eBay listing for a personal air conditioner that used a moist sponge and fan to send some cool relief your way. But he wanted to run his own test to see if it really did anything before laying down the cash.
The idea is to run air past a moisture source. Some of the heat energy in the air is reduced through evaporation resulting in the exhaust air feeling a bit cooler. It’s the same concept used in swamp coolers (an evaporative type of air conditioning). To build his device [Stephen] grabbed a refrigerator deodorizer which uses a hinged plastic cage to hold a packet of baking soda. He attached a small PC fan to the cage, then inserted a damp sponge. This is so easy to put together you could hit the dollar store on your lunch break and have some relief for the second half of the work day.
If you’re looking for a technique that cools just a bit better consider leveraging a beer fridge as a personal cooler.
Continue reading “Quick and easy personal evaporative cooler”
The number one and number two things asked after presentation of our DIYDTG were…
“How does it hold up in the wash?”
“How did you change out the inks?”
While we’ve explained the first several times (regular ink washes out, DTG ink gets a little lighter but survives) we can hopefully answer the second with a tutorial.
Continue reading “(mini)How-To: Refill your DTG inks”
[Aaron] calls this project “Stochasticity”. It uses two sponges as a musical interface. The performer wears a wrist strap and then draws on the table with water from the sponge to play different notes. You really need to watch the video to fully understand what’s going on here.
We’re guessing that this is Arduino based since some of his other projects are as well. You can try out another quick project of his, an Arduino electromagnetic field detector. Check out video of that after the break.
Continue reading “Sponge music”
Etching a printed circuit board generally takes a bit of time and uses a lot of etchant. [TechShopJim] posted a method that uses a sponge to reduce the amount of etchant used while speeding up the entire process. First, a resist is applied using either a sharpie or the toner transfer method. Using gloves to handle everything, he soaked a sponge in ferric chloride and continually wiped a copper-clad board until all the exposed copper was removed. This technique moves the etchant around more, keeping “fresh” etchant closer to the copper. If you can’t procure ferric chloride, you can also use our method that uses 2 household chemicals: hydrogen peroxide and hydrochloric acid.