An ultrasonic audio transmitter receiver system from Vinod S.
Hi all, this is another mad project. Aim of the project is to transmit laptop audio via ultrasound to few meters and then receive it and demodulate it and playback the audio on a speaker.
See the full post on his blog.
Check out the video after the break.
Continue reading “Ultrasonic audio transmitter and receiver system”
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:
Continue reading “Free PCB coupon via Facebook to 2 random commenters”
An open source small DC/DC 3W switcher to drop 5V to 3V in a 7805 TO-220 pinout from Black Mesa Labs:
This post is an open source hardware design from Black Mesa Labs for a simple DC/DC converter for dropping 5V to 3.3V ( or adjustable to lower voltages via resistor selections ). The design is based on the PAM2305 from Diodes Incorporated, a great little 1 Amp step-down DC-DC converter in a small TSOT25 package. The PAM2305 supports a range of input voltages from 2.5V to 5.5V, allowing the use of a single Li+/Li-polymer cell, multiple Alkaline/NiMH cell, USB, and other standard power sources. The output voltage is adjustable from 0.6V to the input voltage.
More details at Black Mesa Labs site.
A how-to on designing a DIY Arduino PCB Pryamiduino from Bald Engineer:
Continuing the DIY Arduino tutorial series, this AddOhms episode shows how to create a PCB in KiCad. I make a joke that the original design was a rectangle, which I found boring and pointless. So instead, I designed a triangle to give the board 3 points. Get it? Puns! I am calling it the Pryamiduino. To be honest, I found not having a constraint to be a problem. By forcing a specific board size and shape, many decisions were more manageable.
More details at Bald Engineer’s blog.
Check out the video after the break. Continue reading “DIY Arduino PCB Pryamiduino”
Here’s the part 3 of Dimitris’ Arduino controlled Dual Mono AK4490 DAC project we covered previously:
Following up on Part 2, it’s time to talk about the output stage.
This output stage is the brainchild of my friend Kostas, all I did was lay out the PCB.
It is a fully discreet single-ended class-A output stage, outputting ~2.4V RMS.
More details on Dimdim’s blog. If you missed part 1 and part 2, be sure to check it out.
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:
Some stuff:
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.
A look at the silicon and circuit board of a common DRAM DIMM by Electronupdate.
See the full post here.
Check out the video after the break. Continue reading “DRAM DIMM teardown”
This video describes how to make and test your own YBCO superconductor by Ben Krasnow.
More info on his blog here.
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:
Application note from STMicroelectronics on the performance of each diode in a parallel diode connection and how the forward voltage dispersion can have a great impact over thermal effect on the current imbalance. Link here (PDF)
The use of diodes in parallel is commonly found in power electronic design. An important consideration for this practice is the current sharing between diodes due to the difference of electrical characteristics. This application note highlights the cause of the behavior of several diodes are connected in parallel. Some recommendations will be given to help the designer to produce a safe design. An electro-thermal model is described which simulates the current and junction temperature of each diode for given application conditions. This tool is illustrated using an example.
App note from ON semiconductors about time delay on start up in conjunction with eFuse to compensate voltage spikes that can falsely trigger them. Link here (PDF)
The eFuse protection devices are used for limiting the system load current in the event of an overload or a short circuit. Many applications employ ON Semiconductor eFuses at the power input stage of the system between the main power input connector and DC−DC converters or power regulators. Such applications often tend to experience a voltage spikes and transients during a hot-plug events, especially when the long cables are used at the power input.
Although ON Semiconductor eFuses are extremely immune to voltage transients and eFuses with the Overvoltage clamp feature provide a fast response when limiting the output voltage during transients, sometimes various applications require a time delay between the hot-plug input voltage application and enabling of the eFuse in order for the input voltage to be stabilized before turning on the eFuse.
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:
Continue reading “Free PCB coupon via Facebook to 2 random commenters”
Mare writes:
There are many battery cell simulators available which could simulate battery cell(s). Unfortunately, none is emulating any of the digital protocols used by fuel gauge devices. Optimal solution to efficiently emulate given smart battery pack is to use custom solution based on battery cell simulator and fuel gauge protocol emulator. Both parts could be fused together in small, but efficient smart battery pack emulator.
- complete battery cell simulation
- fast response time
- unlimited cycle use
- flexible fuel gauge protocol emulation
- use of a standard interface for integration in automated test equipment
More details at Mare & Gal Electronics homepage.
Ben Katz writes:
A while ago I added the hall effect encoder IC I’ve been using directly to the motor controller PCB. The controller sits directly on the back of the motor (with a magnet added to the motor shaft), and the phase wires solder straight in. I also have a pair of board-mounted XT30 connectors on the DC bus for easy daisy-chaining. Otherwise, the board is basically identical to the previous version of this controller. I’ve now built over a dozen of these, and have had no problems.
See the full post on BuildIts in Progress blog.
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:
Some stuff:
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.
James Lewis shares his experience in debugging SONOFF AC relay with a thermal camera:
The clever solution seemed to be clever, at least for a few minutes. Suddenly the light turned off. I thought maybe there was a timeout for the manual button. Annoying, but workable. The lamp remained off for about another 2 minutes when I started to smell that unmistakeable burning plastic odor. Touching the case of the SONOFF identified the culprit immediately.
Great. So I have an AC mains switch that isn’t working, but I do not want to go poking my multimeter into it. What do I do?
Turns out, that SONOFF module was defective. I wanted to debug it, but I did not want to measure anything while connected to AC. Here’s how I used a thermal camera to debug my SONOFF.
See the full post on Bald Engineer blog.
Steve’s (a.k.a N8NM ) ‘$20 Bill’ DC receiver:
If you follow Bill, N2CQR’s SolderSmoke blog, you know that he’s working on a simple DC receiver of his own, which, along with his aversion to using the magic chips, served as inspiration for this rig, which is how it got it’s name: $20 is my guess at what it’d cost to duplicate, and Bill, of course, is Bill. The alternate name is based on my belief that the last thing the world needs is another 40m DC receiver.
More details at Steve’s Eclectic Radio blog.
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:
App note from OSRAM about LED rework on signages and their demand for more sophosticated tools. Link here (PDF)
SMT LEDs have became more and more popular in video wall and signage applications, replacing radial LEDs. This leads to more difficulties during the repair or replacement of failed LEDs on PCBs, especially for QFN (Quad Flat No-lead) packages, as there is no exposed lead. This application note provides basic information on how to rework the SMT LEDs in video wall and signage applications. To describe the rework process the DISPLIX Oval LED was chosen an example, as the rework of this LED is more challenging due to the lack of exposed lead and the oval lens on top. However, the procedure is also suitable for other LEDs. In this application note details on the materials used, examples of suitable equipment and the process are presented and described. Finally, the test results of the LED after the rework process are presented, showing that in this case the rework procedure did not cause any damage to the LED itself.
White paper about matrix LED usage from Integrated Silicon Solution Inc. (ISSI). Link here (PDF)
People today come in contact with a wide range of consumer electronics (CE) devices in their daily lives. CE devices have become increasingly complex with added functionality enabled by MCU’s which provide the intelligence for automating functions. Control panels used in appliances and other equipment leverage MCUs and several integrated circuits to enable functions, such as sensing, process control and user interface (UI).
The user interface consists of input controls, visual and audio feedback used to configure the product to perform complex tasks. An aesthetically pleasing UI is a major differentiating feature for home appliances such as ovens, washing machines and refrigerators. Home appliance UIs commonly use capacitive or inductive touch sensing to provide an easy to clean interface unmatched by mechanical buttons. In addition to touch sensing, a UI has to provide audio and visual feedback in response to the user selection. The UI may not be the most important factor in determining the commercial success of CE devices. However, once parity is established on the major functions such as washing capacity, energy efficiency, etc, the UI becomes a key differentiator. Today, parity has been established on most of the important factors making the UI a product differentiating factor.
As the trend continues to move away from purely mechanical switches to a fully electronic interface expect to see demand for LEDs and drivers to continue increasing.
