Limpkin published a new build: For once, this project was not for me… it was for my wife ! Every morning she takes the bus then train to go to work. If she misses her train, she has to wait for more than 30 minutes for the next one. Not missing her bus is therefore […]
Author Archives: DP
ESP8266 voltage regulator (LiPo and Li-ion batteries)
Rui Santos writes, “In this guide, you’re going to build a voltage regulator for the ESP8266 that can be used with LiPo and Li-ion batteries.” More details at RandomNerdTutorials.com. Check out the video after the break.
App note: Current sensing in metering applications using a pulse current sensor and ST metering devices
App note from STMicroelectronics about current sensing using Rogowski coil together with STPMxx metering device. Link here (PDF) This application note describes the benefits of a current sensing system for metering applications using STPMxx metering devices and a current sensor developed by Pulse Engineering Inc. (hereafter referred to as “Pulse current sensor”), based on the […]
App note: Watt-hour meter based on the STM32F101 microcontroller
ARM Microcontroller based watt-hour meter implementation from STMicroelectronics. Link here (PDF) This document describes, in detail, the hardware and software implementation of a watthour meter using the STM32F101 microcontroller. This cost effective watt-hour meter uses shunt with an operational amplifier as a current sensor, an embedded 12-bit ADC for current and voltage measurement, GPIO for […]
Free PCB coupon via Facebook to 2 random commenters
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 […]
6×1 antenna switch
Mare published a new build: This is complete project for 1×6 antenna switch. It was bult in more than 50 pieces around the world and performs really good. Even big guns use it for their systems. The project was designed with help from other OMs (S55O, S59MA, S50LD, S51CT, S51ZJ, SM2WMV/SJ2W and others). More details […]
Weather logger with Losant and Amazon Alexa
Steve documented his experience experimenting with home weather logging: Like a million other people on the Internet, I’ve been experimenting with home weather logging. I roll my eyes at the phrase “Internet of Things”, but it’s hard to deny the potential of cheap networked sensors and switches, and a weather logging system is like this […]
Transistor radio series – The 7 MHz scratch synthesizer
Vasily Ivanenko has written up documentation on his 7 MHz synthesizer project: Above — All 4 boards were built in re-purposed Hammond boxes. A PIC-based counter sits on top of the offset mixer. I build modular gear and this allows modification and fosters experimentation. When I build a final transistor radio receiver, I plan to […]
#FreePCB via Twitter to 2 random RTs
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 […]
Teardown of an ATVR-1000D AC voltage regulator
Kerry Wong did a teardown of an ATVR-1000D automatic AC voltage regulator and discussed how different types of AC regulators work: The ATVR-1000D utilizes a motor to drive the wiper of a autotransformer (Variac), the servo motor can be driven in either direction depending on the output from the OpAmp (LM324) based comparator. Comparing to […]
Free PCB Sunday: Pick your PCB
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 […]
App note: Thermal design calculations for integrated stepper motor driver solutions
Another technical note from STMicroelectronics on fine tuning motor drivers for optimal thermal design. Link here (PDF) One constant trend in the automotive world is the tendency to reduce the size of electronic components and the ECUs (Electronic Control Unit). While this development has many benefits for the car manufacturer as well as for the […]
App note: Pop & click in audio amplifiers
Technical note from STMicroelectronics about popping noise usually heard on audio amplifiers and how to minimize it. Link here (PDF) Pop and click, or rather, the absence of it, is a characteristic that makes a lot of impact in the world of audio amplifiers. This is especially true for those destined for headphone-equipped applications (such […]
Free PCB coupon via Facebook to 2 random commenters
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 […]
Rework and probe wires for circuit boards
Tips & tricks to add probe wires for low-voltage, low-current signals on small fine pitch circuit boards. Via Electronupdate.
Cheap DIY USB MIDI to CV
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
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 […]
#FreePCB via Twitter to 2 random RTs
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 […]
Reverse engineering of BK Precision 1696 switching power supply’s LCD protocol
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 […]
App note: Characteristics and applications of fast recovery epitaxial diodes (FRED)
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 […]