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Cheap DIY USB MIDI to CV

Posted on Thursday, November 23rd, 2017 in DIY, how-to by DP | No Comments

pumidi2cvlite2

A how-to on making a DIY USB MIDI to CV from DIY Synthesizer:

This one is simple and does not require any expensive Teensy’s or STM32.
It runs on the ATtiny85 using V-USB.
The ATtiny is programmed with the Micronucleus bootloader and is firmware
upgradeable incircuit.

More details at DIY Synthesizer homepage.

A full review of EasyEDA: A circuit EDA online tool

Posted on Tuesday, November 21st, 2017 in site, tools by DP | No Comments

1easyeda

Yahya Tawil wrote in to share his review of a web based EDA tool, the EasyEDA. He explains the general structure of this tool and some of its cool features:

EDA cloud tools which are related to electronics are emerging exponentially in almost all aspects (i.e. simulation, PCB design, footprint creation, gerber files viewing and 3D PCB viewing). Even well-known desktop programs like EAGLE CAD and Altium are trying to compete in this field by making their own services or by acquiring others.
Web-based EDA tool suites like EasyEDA and Upverter are getting rapidly famous. These online tools offer some outstanding solutions for collaboration and providing some viable features for teams with financial limits like multi-layer PCB designing, while it costs a lot to buy a licence for other EDA tool with a multi-layer feature, for example.

More details at allaboutcircuits.com.

#FreePCB via Twitter to 2 random RTs

Posted on Tuesday, November 21st, 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.

Reverse engineering of BK Precision 1696 switching power supply’s LCD protocol

Posted on Monday, November 20th, 2017 in reversed by DP | 1 Comment

ppreverseengineeringwiring-600

Kerry Wong writes:

As mentioned in my previous post, besides the broken LCD there was also an issue with the power supply portion of the unit and the output voltage was clamped at around 10 to 11V. The digital circuitry portion however seemed to be intact. Unfortunately since an identical LCD is virtually unobtanium, I thought I’d reverse engineer the LCD protocol so once the power supply is fixed I can fix the display by hooking up a different LCD.

See the full post on his blog.

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

App note: Characteristics and applications of fast recovery epitaxial diodes (FRED)

Posted on Sunday, November 19th, 2017 in app notes by DP | No Comments

an_ixys_IXAN0044

All about ultrafast diodes app note from IXYS. Link here (PDF)

During the last 10 years, power supply topology has undergone a basic change. Power supplies of all kinds are now constructed so that heavy and bulky 50/60 Hz mains transformers are no longer necessary. These transformers represented the major part of volume and weight of a traditional power supply. Today they have been replaced with smaller and lighter transfomers, whose core materials now consist of sintered ferrites instead of iron laminations and which can operate up to 250 kHz. For the same power rating, high frequency operation significantly reduces the weight and volume of the transformer. This development has been significantly influenced by new, fast switching power transistors, such as MOSFETS or IGBTs, working at high blocking voltages (VCES > 600 V).

Apart from the characteristics of the transitor switches, the on-state and dynamic characteristics of the free wheeling diodes have a significant impact on the power loss, the efficiency and the degree of safety in operation of the whole equipment. They also play a decisive role when it comes to increasing the efficiency of a SMPS and to reduce the losses of an inverter, which clearly mandates that ultrafast diodes be used. The ultrafast diodes described here embrace all characteristics of modern epitaxial diodes, such as soft recovery, low reverse recovery current IRM with short reverse recovery times.

App note: Optimized diodes for switching applications

Posted on Sunday, November 19th, 2017 in app notes by DP | No Comments

an_ixys_IXAN0060

An app note from IXYS about choosing the right diode for efficiency and cost. Link here (PDF)

Great efforts have been made to improve power switches – MOSFETs and IGBTs – to decrease forward voltage drop and as well as to decrease turn-off energy. In switching inductive loads, the turn-on losses depend strongly of the behavior of the companion free-wheeling diode and now form the major part of over-all power losses. New developments like series connected diodes in a single package can greatly improve a given design. This paper shows how to choose the optimum diode using the specific example of a PFC circuit.

Overdrive guitar effects pedal

Posted on Friday, November 17th, 2017 in DIY, how-to by DP | No Comments

pstomp-600

Eddie over at Bantam Tools shared detailed instructions of how to build this DIY overdrive effects pedal:

This project shows you how to make your very own effects stompbox! We’ll go through the steps of downloading the .brd file, loading the file into our software, milling the board on the Bantam Tools Desktop PCB Milling Machine, and soldering the components. This is a great tutorial for those new to milling printed circuit boards (PCBs) or for those who want practice soldering components to the board as a part of a larger assembly.

More info at Bantam Tools project page.

Free PCB coupon via Facebook to 2 random commenters

Posted on Friday, November 17th, 2017 in Free PCBs by DP | 1 Comment

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…)

Arduino controlled Dual Mono AK4490 DAC (part 1)

Posted on Thursday, November 16th, 2017 in Arduino, DIY by DP | No Comments

pDual_Mono_AK4490_05-600

This article is the first of a series detailing the design and build process of an Arduino controlled Dual Mono AK4490 DAC by DimDim:

The design goal was to do a dual mono design so as to maximize SNR and channel separation. A 4-layer PCB design was chosen so as to have a very solid, low impedance ground plane as well as proper power and signal planes. The I2S, audio signals and power after the local LDO regulators are routed on the top layer, the 2 middle layers are ground and power planes, and the bottom layer serves to route I2C signals and some power lines.

See the full post here, Dimdim’s blog.

#FreePCB via Twitter to 2 random RTs

Posted on Tuesday, November 14th, 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.

Schottky diode cross section

Posted on Tuesday, November 14th, 2017 in Teardowns by DP | No Comments

pside1 - Copy-600

The cross section of a 1N5817 20V 1A rectifier diode from Electronupdate.

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

Free PCB Sunday: Pick your PCB

Posted on Sunday, November 12th, 2017 in Free PCBs by DP | 18 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: Adjustable gain with a current sensing

Posted on Sunday, November 12th, 2017 in app notes by DP | No Comments

an_stm_DM00096552

Application note from STMicroelectronics for fine tuning gain on current sensing amplifier. Link here (PDF)

This application note explains how to use current sensing amplifiers with series resistors on the sense inputs. This approach is especially useful for applications where the gain must be adjusted.

App note: Intelligent power switches for 48 V battery applications

Posted on Sunday, November 12th, 2017 in app notes by DP | No Comments

an_stm_DM00327421

Application note on controling Intelligent Power Switches (IPS) from STMicroelectronics. Link here (PDF)

For the last 15-20 years, the automotive electronics market has been moving from electromechanical relays to solid state components for driving all kind of loads.

It is obvious why: solid state components are smaller in size, lighter, silent, easy to mass produce because they are housed in SMD packages, and they boast an unrivaled number of switching activations. On top of this, the solutions based on silicon components have a much higher electrical efficiency and offer useful types of diagnostics such as short-circuit, overload and thermal protections, they can supply an actual image of the current flowing into the load, and so on. In fact, they are called “Intelligent Power Switches (IPS)” or “Smart Power MOSFETs” for good reasons. The key “switching” element is an N-MOSFET, with the relevant charge pump. Around the N-MOSFET, logic interfaces and other elements contribute to the protection of the MOS and they generate and manage diagnostic data.

Teardown of a BK precision 1696 programmable switching power supply

Posted on Thursday, November 9th, 2017 in power supply, Teardowns by DP | No Comments

image1

Kerry Wong did a teardown of a BK Precision 1696 programmable switching power supply:

My original plan was to find a replacement LCD and restore the unit to its original full functionality. But the LCD used in this unit is likely specifically made for the 169X series of power supplies and through some initial research I realized it would be extremely difficult to get hold of unless I could find a donor unit with a functional LCD inside. After I received the power supply, I realized that it had more issues than just the broken LCD itself. During my initial testing, I found that the output would not reach higher than 10 to 11 volts even with the over voltage protection set to the maximum value (20.5V). So clearly I have more homework to do, and for the time being let’s simply strip it down and see what’s inside.

See the full post on his blog.

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

Fascinating details of Waveshare e-paper displays

Posted on Thursday, November 9th, 2017 in part review by DP | 1 Comment

image1

Erich Styger has a nice write-up on Waveshare e-paper displays:

I have used E-Ink displays in projects three years ago, but from that time the technology has greatly evolved. That time displays were hard to get, expensive and difficult to use. Now things seem to change with e-ink displays available to the maker market :-). I’m able to get a 128×296 pixel e-paper display for $10! And for little more money I can have displays with black/white/red colors!

More details at MCU on Eclipse homepage.

#FreePCB via Twitter to 2 random RTs

Posted on Tuesday, November 7th, 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.

How to configure I2C sensors with Arduino

Posted on Tuesday, November 7th, 2017 in Arduino, how-to by DP | No Comments

sensorpan-600

Edward Mallon writes:

I’ve spent the last year in the ‘uncanny valley’ of the Arduino. That’s the point where you understand the tutorials at Arduino.cc, but still don’t get much from the material on gitHub because trained programmers would never stoop to using the wire.h library when they could just roll their own in native C++ using the avr-g++ compiler.  The problem with establishing sensor communication at the level of the TWI peripheral inside the AVR is that there are so many fiddling details to keep track of that it quickly overruns the 7±2 things this average human can hold in his head at one time: Computers aren’t the only things that crash after a buffer overflow!  So this post is meant to be a chunking exercise for beginner-intermediate level people like myself who want to get a new sensor working using the standard IDE.  I’ve tried to distill it all down to things that I run into frequently, but there’s still a lot of material here:  So pour yourself a cuppa before diving in…

More details at Arduino based underwater sensors blog.

App note: Position sensing technologies in automotive applications

Posted on Sunday, November 5th, 2017 in app notes by DP | No Comments

an_tt_electronics_autopad

An Autopad(TM) sensor from TT Electronics provides a new non contact position sensing. Link here (PDF)

Automotive design engineers are continuously seeking components that offer performance and flexibility beyond those of conventional position sensing technologies. Further still are the requirements that these devices be versatile and adaptable to a wide range of applications. This demand has led to the need for devices incorporating the best design elements from conventional contacting and non-contacting sensor technologies.

Free PCB Sunday: Pick your PCB

Posted on Sunday, November 5th, 2017 in Free PCBs by DP | 12 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…)

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Recent Comments

  • Pekka Akselin: This is ridiculous!? :-) We are back at 256(!) byte EPROMs that needed multiple, a handful, of voltages to run! :-(
  • KH: Let's try a back-of-envelope calc balancing energies. From MCP1700 datasheet, there are graphs for a 200mA load step. Estimate the energy shortfall as 12uJ. Say...
  • Daniel: It's been a week and my comment is still awaiting moderation. Apparently the CIA doesn't want their involvement known?
  • KH: Agree, so okay, I guess he must have learned from somewhere. 100nF and 1000uF is so far apart, that was jarring; it's more magic incantation...
  • Max: I have a suspicion the hefty electrolytic cap might be some sort of cargo cult carry-over from other RF-based projects - for instance, I've seen...