App note: Low ESR tantalum capacitors make a difference in circuit designs

App note from Vishay about how ESR in tatalum capacitors affect circuit performance. Link here (PDF)

When choosing a capacitor for any application, there are a few key characteristics that must be understood in order to analyze its suitability for the circuit. In a simple capacitor equivalent circuit model, there are three key characteristics that affect circuit performance: capacitance, equivalent series resistance (ESR), and inductance. The magnitude of these elements and how they change over temperature, frequency, and applied voltage are different for each capacitor technology.

App note: The benefit of using a three sense pin design on battery

App note from Vishay about correcting error when reading current on small valued shunt resistor using third pin. Link here (PDF)

The low values of battery shunts being produced today necessitate the use of precision analog to digital converters (ADCs) to interpret the voltage drop across the shunt’s element. Many of these precision ADCs require the sense pins to be within a certain voltage range of the ADC’s analog ground reference input.

App note: Bad block information introduction

App note from Macronix all about NAND flash bad blocks management. Link here (PDF)

Today, NAND flash is used in many fields, such as consumer, industrial, and automotive. Compared with NOR flash, NAND flash has the advantage of availability at higher densities and lower cost per bit. However, NAND flash has the disadvantage of requiring system management of bad blocks, while NOR flash does not. This application note describes how Macronix marks bad blocks in NAND flash and recommends the creation and usage of a bad block table to properly manage bad blocks.

App note: Enhancing system security with Macronix(TM) flash

Technical note from Macronix about built-in and hardware security strategies on their flash memories. Link here (PDF)

Attacks on a system typically alter or copy the content of the Flash image for three primary reasons, which are to:

  • operate the system in an unauthorized manner with the purpose of committing fraud against the user or service provider.
  • disrupt the functionality of many systems through a denial of service.
  • reverse-engineer the system in order to clone its data/code or to exploit its security weaknesses.

To achieve the above goals, both hardware and software skills are needed. The attack may come from direct tampering of a single system or from software spread through viruses in connected devices. The systems that more frequently have to deal with security are those connected to payment/billing services such as Set-Top Box, mobile devices (such as smart phones) and metering devices.

Simple DIY active load

Charles Ouweland designed and built his own simple DIY active load, that is available on Github:

At first I was messing about with some big resistors but then I decided it would be nice to have an “active load” that you can set to a particular current. You can buy these things for quite some money but I decided to design and build myself a simple one using components and tools I have lying around. I decided to go analog, no digital stuff this time.

See the full post on Charles Ouweland’s blog.

App note: A sensible 30A energy meter

Technical paper from Analog Devices about wide range energy meter LTC2947 that eliminates the need for unique and expensive sense resistor values. Link here (PDF)

Monitoring energy has similar benefits in many applications, not just solar. Handheld, rack-mounted and in-line energy meters are widely available and can be used by people such as facility managers to track and allocate energy used by equipment or departments among many things. This may also include load profiling, where expected energy consumption patterns are compared to present usage and areas of concern are flagged based on deviations from modeled energy patterns. By sizing loads, people can determine how many widgets, including lights, computers, batteries, can be connected to a system at any time. Electric bikes and vehicles can report their energy use per mile and quantify the energy being extracted from or returned to a battery.

App note: Achieving a stable power supply with fast transient response through digital control

Technical white paper from Renesas on using digital control loop to achieve more stable power supply. Link here (PDF)

New trends and changing requirements in the power management industry influence how we design power supplies. Some, like the need for telemetry and system information, are more recent due to advancements in technology. Others, like the demand for smaller solutions, higher levels of integration, faster transient response and high switching frequencies, have been around for decades. But throughout the entire history of power system design there has been one requirement that has been constant: the need for a stable power supply.

This article details the common problems plaguing analog voltage mode control loops and shows how a digital control loop is able to provide bandwidth that was previously dismissed as unobtainable. By walking through the variables associated with stability and comparing it to an analog control system, it can be seen that a digital control loop is able to achieve faster transient response and improved performance while maintaining a stable loop.

ESP8266 MP3 sound machine v2

Zack Lalanne writes:

Last summer, I made an ESP8266 MP3 Sound Machine using ESPHome to play calming sounds when my son goes to sleep. I used ESPHome to develop the firmware so it could communicate with my Home Automation platform, Home Assistant. Well, requirements change and projects need updating. So over the holidays, I created a v2.0 of the project.

See the full post at selfhostedhome.com.

An experimental HF 6-band SSB transceiver

Peter (DK7IH) has been working on HF 6-band SSB transceiver:

Part 1: Project Basic Outline Presentation
Part 2: The Oscillators (VFO, LO and Testtone Osc.)
Part 3: The Microcontroller (ATMega128)
Part 4: Bandswitching Logical Circuits
Part 5: Measuring Transceiver Data
Part 6: The Receiver
Part 7: The Transmitter
Part 8: Transmit/Receive Switch Unit
Part 9: Mechanical construction

Project details on Radiotransmitter site.

PoE-Powered VFD tube clock

Glen Akins’ PoE-powered vintage VFD tube clock:

This is a vintage VFD tube clock that uses Ethernet for both power and data. The power is provided using 802.3at PoE+ and a Molex PD Jack that contains both integrated magnetics and a PoE Type 2 PD controller. The IP stack runs on a Microchip PIC18F67J60 microcontroller that has an integrated Ethernet MAC and PHY. The IP stack includes DHCP, DNS, NTP, and LLDP functionality.

Project info at bikerglen.com.

Check out the video after the break.

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U-AMP – open source versatile audio amp

An open source universal audio amplifier called ‘U-AMP‘ @ GmanModz, that is available on GitHub:

Using what I learned getting digital audio working on each systems, I set out on a new project I would call “U-AMP” (Universal-Amp). This would be ONE pcb which has the features of seamlessly integrated speakers and headphones with a variety of input sources for digital audio from Wii, PS2, Dreamcast, as well as analog audio input. It does it all. The board is based around the LM49450 IC which I have used many times. The amp is controlled by a PICLF15324; the LF version of the same PIC I use in the WiiPMS.

See project details at gmanmodz.com.

App note: Monitoring additional supplies with the ADM1062–ADM1069 super sequencers

App note from Analog Devices about ways to extend capabilities of their ADM106x supply supervisor and sequencer chip. Link here (PDF)

The ADM1062–ADM1069 Super Sequencers accurately monitor a number of input rails. The ADM1062–ADM1067 have 10 input pins dedicated to monitoring (VH, VP1 to VP4, VX1 to VX5) and the ADM1068 and ADM1069 have eight (VH, VP1 to VP3, VX1 to VX4). Each of these pins has two internal programmable comparator circuits. By programming these circuits undervoltage only, overvoltage only or undervoltage and overvoltage trip points can be set up around each monitored supply. These trip points are 1% accurate at all allowable voltages and across the entire operational temperature range of the devices.

Ionization chamber

Robert Gawron has posted an update on his Ionization chamber project we covered previously:

Ionization chamber is a device to measure radioactivity level. When air’s atoms are hit by radioactive particles, an ion-pair is produced. Ions has electric charge, if they are in electric field create by positive and negative electrodes, negative ions will move to positive electrode and positive will move to negative electrode. They will try to “meet each other” thus creating a current. This current can be measured. The current is proportional to amount of ion-pairs. Amount of ion-pairs is proportional to radioactivity level.

More details on Gawron’s blog.

Inside the digital clock from a Soyuz spacecraft

Ken Shirriff has written an article on reverse engineering a “Onboard space clock” from a Soyuz mission:

We recently obtained a clock that flew on a Soyuz space mission.1 The clock, manufactured in 1984, contains over 100 integrated circuits on ten circuit boards. Why is the clock so complicated? In this blog post, I examine the clock’s circuitry and explain why so many chips were needed. The clock also provides a glimpse into the little-known world of Soviet aerospace electronics and how it compares to American technology.

See the full post at righto.com.

App note: Failure signature of electrical overstress on power MOSFETs

Nexperia app note about MOSFET’s destruction investigative hints that can be used for design improvements. Link here (PDF)

When Power MOSFETs fail, there is often extensive damage. Examination of the size and location of the burn mark, the failure signature, provides information about the type of fault condition which caused the failure. This document provides a catalogue of failure signatures from common electrical overstress failure modes. The catalogue can be used in forensic investigation of the underlying root cause of failure to improve module design and reliability.

App note: Designing in MOSFETs for safe and reliable gate-drive operation

This app note from Nexperia discuss’ gate drive designs for safe operation of MOSFET. link here (PDF)

The MOSFET gate-source threshold voltage (VGS-th) and maximum gate-source voltage (VGS-max) are key parameters that are critical to the reliable operation of MOSFETs. The threshold voltage represents the voltage at which the MOSFET starts to turn on, whilst the maximum gate-source voltage is the maximum gate-source voltage that the MOSFET can withstand safely. VGS-max ratings vary between suppliers and between MOSFETs, which can make it difficult to choose appropriate MOSFETs for the application.

24-bit stereo audio DAC for Raspberry Pi

Dilshan Jayakody has published a new build:

This project is about 24-bit stereo DAC, which we build for Raspberry Pi boards. This R-2R ladder DAC is developing around Intel / Altera EPM240T100C5N CPLD.
We developed this module after review the PT8211 DAC, which we tested a few months ago. Compare with PT8211 DAC, this module is capable to provide high-quality audio output with Raspbian OS.

See project details on Jayakody’s blog. Project files are available on GitHub.

Simple VU-meter circuit

VU-meter circuit built on a breadboard using transistors, diodes, resistors, and LEDs @ Build Electronic Circuits:

It’s basically a simple display for showing a value. It’s originally for showing signal level in audio circuits, but there’s no reason you can’t use it to show temperature, rain intensity, light level, or whatever other value you are measuring.

Check out the video after the break.

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