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Free PCB coupon via Facebook to 2 random commenters

Posted on Friday, July 28th, 2017 in Free PCBs by DP | 2 Comments

BP

Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. The coupon code usually go to Facebook ‘Other’ Messages Folder . More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three times every week:

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0-30V/0-7A power supply unit with LM723 and Arduino volt and ampermeter

Posted on Thursday, July 27th, 2017 in power supply by DP | 2 Comments

pics-sursa_finalizata_albasete-600

Nicu Florica has been working on a power supply project, inspired by Albasete’s power supply unit with LM723 and Arduino volt and ampermeter:

It use an Arduino nano board with i2c LCD1602 display, a active buzzer for indicate shortcircuit case. Also, I put DS18B20 temperature sensor and relay for power a cooler when tenmperature is bigger than a threshold level.
For albasete version, I write psu_reber_ver3ro.ino sketch. In this sketch I put value for albasete case (R1 = 1k put between GND and A1 port, R2 = 39k put between +OUT and A1) and value for threshold (temax) and hysteresis value

See the full post and more details on his blog, Arduinotehniq.

Pimp your PCB businesscard full color

Posted on Wednesday, July 26th, 2017 in PCBs, techniques by DP | No Comments

pics-pcb_decal-1080x675-600

Here is a nice PCB businesscard @ smdprutser.nl

As a good electronic hobbiest tradition I started to design a businesscard from PCB material. Downside of all the businesscards (and PCBs in general) is the limited number of colors you can use: FR4, soldermask (with or without copper behind it), silkscreen or bare copper. Since the soldermask is fixed for both sides that was an extra limiting factor.
An out of the box solution I found was decal slide paper. This is a printable plastic film that is used to decorate ceramics or glass. There are clear and white versions and they can be found in most hobby stores. They are easily printed on by an inktjet or laser printer and have thus an infinite range of colors. For this experiment I bought clear film and designed the PCB with black soldermask (needed that color for the front side) and white silkscreen.

More details here.

#FreePCB via Twitter to 2 random RTs

Posted on Tuesday, July 25th, 2017 in Free PCBs by DP | No Comments

BP

Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week:

  • Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch it every Sunday, right here on the blog
  • Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
  • Facebook PCB Friday. Free PCBs will be your friend for the weekend

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • Check out how we mail PCBs worldwide video.
  • We’ll contact you via Twitter with a coupon code for the PCB drawer.
  • Limit one PCB per address per month please.
  • Like everything else on this site, PCBs are offered without warranty.

We try to stagger free PCB posts so every time zone has a chance to participate, but the best way to see it first is to subscribe to the RSS feed, follow us on Twitter, or like us on Facebook.

HydroBot: Prototyping new modules

Posted on Tuesday, July 25th, 2017 in DIY, open source by DP | 2 Comments

ProtoModule-600x400

Matthew Reed writes:

ProtoModule is a HydroBot module designed to easily develop and test new monitoring or control functions that may someday go into a HydroBot module. It has 11 GPIO pins and the power rails broken out on a 0.1” pin header for easy breadboarding or interfacing with ribbon cables. The provided pins give access to a variety of digital and analog I/O, as well as digital communication peripherals, to allow for many flexible design options.

More info at protofusion.org.

BSide ACM03 plus clamp meter review and teardown

Posted on Monday, July 24th, 2017 in Teardowns by DP | 1 Comment

pics-acm03plus-600

A review and teardown of a cheap Hall effect clamp meter (ACM03 Plus) from Kerry Wong:

I recently purchased a BSide ACM03 Plus clamp meter so that I could do some high current measurements for my tab welder project. This meter can be bought on eBay for around $25, which makes it one of the cheapest Hall effect clamp meters on the market that is capable of measuring both AC and DC current.
Since this is such a cheap meter, I wasn’t expecting much. But it actually feels really sturdy in hand and the construction looks reasonably solid, which is certainly a good start. It came with a nice little black pouch inside a non-descriptive cardboard box. It even includes a decent product manual.

More details on Kerry D. Wong’s blog.

Check out the video after the break. (more…)

Driving a 48-segment RGB LED bar graph with a Teensy 3.2

Posted on Monday, July 24th, 2017 in LEDs by DP | No Comments

pics-IMG_20170723_133700-600

Glen Akins writes:

In my post Driving a SparkFun 48-Segment RGB LED Bar Graph, I stated that the hardware built there could be used to drive the LED bar graph with any combination of hardware and software that could drive one of the common 32×32 or 32×16 RGB LED matrices. Today I’m back to prove that point. In this post, I ditch the FPGA and drive the 48-segment RGB LED bar graph using a Teensy 3.2 board and the Pixelmatix SmartMatrix 3 library.

More details at Glen Akins’ blog.

Free PCB Sunday: Pick your PCB

Posted on Sunday, July 23rd, 2017 in Free PCBs by DP | 22 Comments

BP-600x373

We go through a lot of prototype PCBs, and end up with lots of extras that we’ll never use. Every Sunday we give away a few PCBs from one of our past or future projects, or a related prototype. Our PCBs are made through Seeed Studio’s Fusion board service. This week two random commenters will get a coupon code for the free PCB drawer tomorrow morning. Pick your own PCB. You get unlimited free PCBs now – finish one and we’ll send you another! Don’t forget there’s free PCBs three times every week:

(more…)

App note: Clearing Xilinx FPGA configuration to allow boundary scan testing

Posted on Sunday, July 23rd, 2017 in app notes by DP | No Comments

Another application note from XJTAG on preparing Xilinx FPGA for proper boundary scan testing. Link here

When Xilinx FPGAs are configured it can restrict the boundary scan access to some signals on the device. One work-around for this problem is to configure the FPGA with a ‘blank’ image that closely matches its unconfigured state, allowing boundary scan testing to occur without any problems.

A second issue that can affect boundary scan testing with FPGAs is that they contain pull resistors. Depending on the design, these may be enabled when the FPGA is unconfigured as well as when it is configured. If these internal resistors are enabled on nets that contain pull resistors mounted on the board, two potential problems can occur:

1. If the internal resistor and external resistor pull in opposite directions, the boundary scan tests may not be able to test the external pull resistor if it is weaker than the internal pull resistor.
2. If the internal and external resistors pull in the same direction, a fault with the external resistor may not be detected because the internal resistor may mask the fault.

By setting the correct configuration options it is possible to disable these internal pull resistors when generating a ‘blank’ FPGA image.

App note: Using a test reset section to initialise JTAG devices

Posted on Sunday, July 23rd, 2017 in app notes by DP | No Comments

an_xjtag_test_rst

An app note from XJTAG about applying test reset to put some devices to JTAG compliant mode. Link here

Some JTAG devices require a specific sequence of states to be applied to some signals in order to put the device into a JTAG-compliant mode. This application note describes how a Test Reset section can be used to describe the required sequence and control its application.

Free PCB coupon via Facebook to 2 random commenters

Posted on Friday, July 21st, 2017 in Free PCBs by DP | 2 Comments

BP

Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. The coupon code usually go to Facebook ‘Other’ Messages Folder . More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three times every week:

(more…)

Battery adapter teardown and Sony A6000 power-off current draw

Posted on Wednesday, July 19th, 2017 in Teardowns by DP | 4 Comments

 

poweroffcurrent-600

Kerry Wong did a teardown  of a battery adapter for the Sony A6000 mirrorless digital camera and measured the poweroff current draw of the the camera:

With the battery adapter on hand, I decided to take a look at what’s inside and then use the adapter to measure the power-off/stand-by current of the Sony A6000.
I was not expecting to see much inside this battery adapter. After all, all it needs is the connection between the battery terminals and the input power jack and a resistor between the center pin and the ground in place of the thermistor that is used to sense the temperature of the battery pack. At the most, it might also include a reverse polarity protection diode.
But a quick measurement suggested that there must be some active components inside as the adapter itself draws around 17 µA current when connected to the power source. So clearly, there is some active circuitry inside.
Upon opening up the battery adapter, I was surprised to see the circuit board inside.

More details on Kerry D. Wong’s blog.

Check out the video after the break. (more…)

Bus Pirate v3 free PCB build

Posted on Wednesday, July 19th, 2017 in builds, Bus Pirate by DP | No Comments

1freepcbbuild

@vijayenthiran tweeted picture of his free Bus Pirate v3 PCB build. The Bus Pirate is an open source hacker multi-tool that talks to electronic stuff.

If you build a free PCB we’ll send you another one! Blog about it, post a picture on Flicker, whatever – we’ll send you a coupon code for the free PCB drawer.

Get your own handy Bus Pirate for $30, including world-wide shipping. Also available from our friendly distributors.

#FreePCB via Twitter to 2 random RTs

Posted on Tuesday, July 18th, 2017 in Free PCBs by DP | No Comments

BP

Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week:

  • Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch it every Sunday, right here on the blog
  • Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
  • Facebook PCB Friday. Free PCBs will be your friend for the weekend

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • Check out how we mail PCBs worldwide video.
  • We’ll contact you via Twitter with a coupon code for the PCB drawer.
  • Limit one PCB per address per month please.
  • Like everything else on this site, PCBs are offered without warranty.

We try to stagger free PCB posts so every time zone has a chance to participate, but the best way to see it first is to subscribe to the RSS feed, follow us on Twitter, or like us on Facebook.

Pogo pin test board for ADB-USB Wombat

Posted on Tuesday, July 18th, 2017 in testing by DP | No Comments

pics-20170716_150939-600

A pogo pin tester for the ADB-USB Wombat board from Big Mess o’ Wires:

Here’s a test rig for the ADB-USB Wombat board: my first-ever project whose sole purpose is to facilitate testing of another project. It uses spring-loaded pogo pins to create a bed of nails that fit into test points on the Wombat board. I can drop a new Wombat board onto the tester, clamp it in, and then program and test it with just a few button clicks. This is a huge improvement over my old manual testing method, which involved multiple cable connections and disconnections, and hand-verified keyboard/mouse emulation on two separate computers. That sort of test process is fine for building a few units, but something faster and easier is needed to support higher volume assembly.
Pogo pins contain tiny internal springs. When a Wombat board is pushed down onto the bed of pins, they compress a few millimeters in length. This helps to create a reliable electrical contact for each pin, even if the uncompressed lengths of the pogo pins are slightly different or they’re not perfectly aligned.

Check out the video after the break.

(more…)

Free PCB Sunday: Pick your PCB

Posted on Sunday, July 16th, 2017 in Free PCBs by DP | 28 Comments

BP-600x373

We go through a lot of prototype PCBs, and end up with lots of extras that we’ll never use. Every Sunday we give away a few PCBs from one of our past or future projects, or a related prototype. Our PCBs are made through Seeed Studio’s Fusion board service. This week two random commenters will get a coupon code for the free PCB drawer tomorrow morning. Pick your own PCB. You get unlimited free PCBs now – finish one and we’ll send you another! Don’t forget there’s free PCBs three times every week:

(more…)

App note: Linear power MOSFETS basic and applications

Posted on Sunday, July 16th, 2017 in app notes by DP | No Comments

an_IXYS_IXAN0068

Some examples of power MOSFETS application from this app note from IXYS Corporation. Link here (PDF)

Applications like electronic loads, linear regulators or Class A amplifiers operate in the linear region of the Power MOSFET, which requires high power dissipation capability and extended Forward Bias Safe Operating Area (FBSOA) characteristics. Such mode of operation differs from the usual way of using Power MOSFET, in which it functions like an “on-off switch” in switched-mode applications. In linear mode, the Power MOSFET is subjected to high thermal stress due to the simultaneous occurrence of high drain voltage and current resulting in high power dissipation. When the thermo-electrical stress exceeds some critical limit, thermal hot spots occur in the silicon causing the device to fail

App note: Depletion-Mode power MOSFETs and applications

Posted on Sunday, July 16th, 2017 in app notes by DP | No Comments

an_IXYS_IXAN0063

IXYS Corporation’s N-Channel power MOSFET selection and application. Link here (PDF)

Applications like constant current sources, solid-state relays, telecom switches and high voltage DC lines in power systems require N-channel Depletion-mode power MOSFET that operates as a normally “on” switch when the gate-to-source voltage is zero (VGS=0V). This paper will describe IXYS latest N-Channel Depletion power MOSFETs and their application advantages to help designers to select these devices in many industrial applications.

Akafugu modular VFD clock review

Posted on Friday, July 14th, 2017 in clock by DP | 5 Comments

akafugu-vfd

Manuel Azevedo did a review of Akafugu’s modular VFD clock:

I discovered this wonderful tiny VFD clock by chance, while browsing Tindie for novelties. As I’m a newcomer to this Nixie/VFD world, I was not aware that Brian Stuckey already did an article in 2014 on a previous incarnation of this clock (Akafugu Modular VFD Clock).
I contacted Per Johan Groland, owner of the Japanese maker Akafugu that makes these clocks, for all the shields I could get my hands on – The only shield I did not order was the 4 tube IN-4/17 shield, which Brian already tested and which I find does not do this clock justice.

See the full post and more details on his blog, TubeClockDB.

Check out the video after the break. (more…)

Free PCB coupon via Facebook to 2 random commenters

Posted on Friday, July 14th, 2017 in Free PCBs by DP | 2 Comments

BP

Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. The coupon code usually go to Facebook ‘Other’ Messages Folder . More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three times every week:

(more…)

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