Author Archives: DP

App note: Power factor correction using the IRS2500

Drop in replacement power factor correction chip IRS2500 from International Rectifier. Link here (PDF) Many offline applications require power factor correction circuitry in order to minimize transmission line losses and stress on electrical generators and transformers created by high harmonic content and phase shift. Appliances often incorporate switching power supplies (SMPS) which include capacitive filter […]

App note: Low-Power Real Time Clock

An application note (PDF!) on low-power real-time clock from Microchip: This application note uses the Timer1 module, from a mid-range PIC16CXXX microcontroller, to control a low-power real-time clock. Timer1 was chosen because it has its own crystal which allows the module to operate during sleep. The two events that will wake the device from sleep […]

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 […]

‘Magic tree’ project

Dilshan Jayakody has published a new build, a ‘Musical trees’: “Musical trees” is a part of creative arts installation and this project is capable to produce different audio tones by detecting human touch to its attached plants. Existing version of this driver is capable to monitor 8 plants and produce different sounds for each plant. […]

mavroOBD, an open source Arduino compatible OBD/Can-Bus module

Mavromatics’ open source project designed to “hack” your vehicle, that is available on github: The goal of this project it to create an Arduino based OBD port module that can be used to enhance a vehicles capabilites. For example, if you want door locks to close when moving faster than 5mph or to invoke/emulate certain […]

flip-flop/BCF project

Ray over at the diyAudio forum has been working on his flip-flop/BCF project: I’ve just finished a project to roll up the developments into a more ‘finished’ build, feeding the balanced outputs from the flip-flop board into a Broskie BCF buffer stage. I’m using Nicks MJ Statistical Regulator for the B+ and one of Andrew’s indirect filament […]

Using “Ultracapacitors” as a power conditioner and ballast for transient high-power loads (or “How to run your HF rig from D-cells” – sort of…)

KA7OEI writes: An advantage of Lead-Acid, NiCd, Lithium Ion and some NiMH cell types is that they have quite low internal resistance compared Alkaline cells: Even an aging lead acid battery that is near the end of its useful life may seem to be “OK” based on a load test as its internal resistance can […]

Crystal Ladder filter

Dan Watson writes: Here’s a little board for making a four pole crystal ladder filter. This type of filter has a very high Q and narrow bandwidth, allowing you to select a specific frequency from your signal. Because of the narrow bandwidth, selection of the capacitors and tuning of the filter is important to achieve […]

App note: Auto-zero amplifiers ease the design of high-precision circuits

An application note from Texas Instruments on new chopper amplifers superiority over old design chopper amps. Link here (PDF) This article shows that the auto-zero calibration technique is very different from the chopper technique and is one that, when implemented through modern process technology, allows the economical manufacturing of wideband, high-precision amplifiers with low output […]

App note: Transmitting SXGA video signal through 1kft (300m) CAT-5 cable

An app note from Intersil on utilizing CAT-5 cable for SXGA video transimission. Link here (PDF) The goal of this application note is to present the most current design methods for transmitting high bandwidth SXGA video signal over long distances of CAT-5 cable (300m or more). The enormous cost benefits of CAT-5 cable will also […]

App note: USB Mass storage class on an Embedded Host

Microchip’s application note (PDF!) on USB Embedded Host Mass Storage class: With the introduction of Microchip’s microcontrollers with the USB OTG peripheral, microcontroller applications can easily support USB Embedded Host functionality. One of the most common uses of this capability is to interface to mass storage devices, such as USB Flash Drives and memory card readers. […]

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 […]

Output voltage control of DC/DC converters

Thomas Fischl writes: Some applications needs to control the output voltage of a dc/dc converter instead using a fixed output voltage. For example battery chargers has to adjust the output voltage to the current battery level. This page shows how to add such a control function to a buck converter circuit. Control output via external […]