Open Position for Step-Up Converter

For a current project I need a step-up converter to get 5 volts from 2.5V-5.5V input. The output of this converter is used to power sensors which drive motors and small heat elements from this source. The average consumed current is 160mA with a peek at 320mA.

In the photo you can see the latest Boldport project with a test setup for the XC9142B50DMR-G from Torex Semiconductor. I made the mistake and just relied on the specifications stated on the website from Mouser:

mouser-info.png

This looks really good: 500mA output current… So I did a quick test. Obviously the magic smoke in the photo is a composition, but this is what actually happened somewhere at a constant ~250mA load with 5V input. Continue reading Open Position for Step-Up Converter

Adafruit PCB Coaster Arrived

Today I got the PCB coaster from Adafruit. They look so much better in real than on the photos in the shop. The coasters are made from 2.4mm FR4 PCB material. There is a transparent solder mask on the top to protect the copper and gold elements. The frame around the image is black silkscreen.

I really like the combination of the cold and coper colours.

The coasters were designed by Saar Drimer at Boldport. You can buy them in the Adafruit shop.

lucky-resistor-1

lucky-resistor-2

Boards in Good Quality from SeeedStudio Fusion

SeedStudio offered me a coupon to evaluate their PCB service “Fusion“. I am currently working on a new project, so I gave this service a try. I used the following options ordering the two boards:

PCB Dimensions 68mm*108mm
Impedance Control No
Surface Finish HASL Lead Free
Minimum Solder Mask Dam 0.4mm↑
Copper Weight 1oz.
Plated Half-holes / Castellated Holes No
Minimum Drill Hole Size 0.3mm
PCB Color Blue
Base Material FR-4 TG130
No. of Layers 2 layers
PCB Quantity 5
Blind or Buried Vias No
PCB Thickness 1.6
Trace Width / Spacing 6/6 mil

I payed $27.40 for five boards with the option shown above and there were additional $20 shipping costs.

My board design has a very low quality class B4: Minimum drill size is 0.35mm, minimum trace size and spacing is 0.2mm.

Ordering and Shipping

The order process was very simple. The website provides an assistant with all possible options and calculates a quote in real time. I just noticed these minor things:

  • The shipping cost is not displayed in this quote.
  • The dimensions were not correctly extracted from my Gerber files.

The production of the boards and the shipping was quite fast, the whole process only took 10 days until the packet with the boards arrived.

lucky-resistor-1

The boards were well protected in the package, so there were no scratches from the shipping of the boards.

Quality

The boards have a good quality for the chosen options and the price. The alignment of the layers is not perfect, but everything is in an acceptable range.

lucky-resistor-12

The front side of the two boards. Continue reading Boards in Good Quality from SeeedStudio Fusion

Snow Flake Power Converter

I designed a very simple power converter for the snow flake decoration. The snow flake boards require 3.3V, a voltage which is not commonly available in a household. Therefore the power converter takes 5V USB power and convert it into the required 3.3V.

There is no fancy circuit inside of this box, lazily I simple used a Traco Power TSR2-2433 DC/DC power converter. It is a single component containing everything required. No external components like capacitors or resistors needed.

lucky-resistor-5

Continue reading Snow Flake Power Converter

Snow Flake Component Side

Today I show you a little bit longer video about the assembly of the component side of the snow flake panel.

Compared with the very small 0402 LEDs (1mm x 0.5mm) on the front side, the component side contains just regular 0805 resistors and capacitors.

The first part of the video shows how I apply the solder paste using a metal stencil. I use a system called “eC-stencil-fix” from Eurocircuits. This is basically a set of plates with metal knobs to perfectly align the board with the stencil. With a tick in a checkbox, they produce panels which perfectly work using this stencil fix system, which is really convenient.

Continue reading Snow Flake Component Side

Perfect Snow Flake Panels from Eurocircuits

Eurocircuits delivered some perfect panels for the snow flake board. Each panel has five snow flake boards on it.

lucky-resistor-4

This was an impressive good job from from Eurocircuits. There are a quite number of challenges to produce panels in this outstanding quality:

  • The width of the small decorative lines on the front is just 0.15mm. It is hard to get the HAL evenly over the whole surface with lines in all directions like this.
  • White solder mask would show every imperfection. You really can not hide a thing with this colour, it benefits greatly from a clean-room.
  • Milling this board outline is not simple either. You need experience, where to place the bridges to create a stable panel.

lucky-resistor-1

Most vias are tented, which is very nice. These are 0.25mm diameter holes, so it is at the upper limit where tenting works.

I am very happy with the result! The people at Eurociruits have clearly demonstrated their skills and commitment to quality.

Now it will be a real challenge to assemble the board without leaving any marks on the white surface. 🙂