8-Bit Blog: China Edition (Day 3) September 13 2013
Greetings everyone! Day 3 here. As many of you know, the Question Block Lamp is controlled by a capacitive touch sensor. One of the toughest problems with a touch sensitive product is that the sensitivity can change with a variety of factors. This can include humidity, temperature, and skin conductivity (which is affected by oil or sweat). When designing and testing the lamp, we accounted for all of these, and made sure that everything would work under a variety of conditions. However, we didn't expect that the power supply might also have an effect.
Enter Mr. Yang. He runs a power supply factory here in Shenzhen, and has been working over the past several months with us to make sure our lamp will work in countries all over the world. We found initially that different voltages (e.g. 120V in the US, 240 in Europe) could have an effect on the sensitivity.
In order to solve for this, we needed a power supply that blocked any noise and interference that had an effect. Mr. Yang and his team of electrical engineers were able to help us figure out exactly what caused changes, and find a power supply that will work around the world.
Ever been curious how power supplies are made? I use them pretty much every day (to charge my cellphone and laptop) but had never actually seen their insides.
Well, the first step is to add all of the small surface mount components to the blank circuit boards. This is often done with a pick-and-place machine, which is a robot that very precisely and rapidly places all the components on a board. At Mr. Yang's factory, they have two pick-and-place variations that they use for their power supplies.
Larger components must be added by hand on an assembly line. These are then fed into an oven which cooks the solder and solidifies the connection.
These are stacks of completed power supplies. All that's left is to insert them into an injection molded case, and add an appropriate attachment. For our supplies this will be a USB slot. For many others, this will be a cable with a specified length.
Before leaving the factory, every adapter is run through a battery of tests that last several hours. This is conducted in a very hot room, to make sure that the supplies can function at high temperatures. The machines will automatically test each adapter, and display success and failure with LEDs.
After the factory visit, I met up with the hardware accelerator in Shenzhen, HAXLR8R (pronounced hack-sell-er-ate-er). We all went out to Karaoke nearby and had a pretty great time. Here's everyone rocking out to YMCA.
That's all for this week folks! This weekend I'm going to check out a famous painting village called Da Fen. Much of the art that's sold in Shenzhen and the surrounding areas comes from this village. Stay tuned!