Author Archives: DP

App note: HVArc Guard® surface-mount capacitors for low-power voltage multiplier applications

Application note on Vishay’s arc resistant SMD capacitors, Link here (PDF) Voltage multipliers can generate very high voltages due to an inverter circuit that feeds a step-up transformer, which is connected to the multiplier circuit. An example of a typical voltage multiplier, which is simply a circuit comprised of capacitors and diodes that charge and […]

App note: AC film capacitors in connection with the mains

An application note from Vishay about choosing the right filter capacitors that are placed directly on mains. Link here (PDF) To help reducing emission and increasing the immunity of radio interference, electromagnetic interference suppression film capacitors (EMI capacitors) are playing a major role in all kind of applications. These capacitors are put directly parallel over […]

App note: Modern PRTD temperature sensors and high-resolution Delta-Sigma ADCs enable wide range high-accuracy temperature measurements

Modern PRTD temperature sensors and high-resolution Delta-Sigma ADCs enable wide range high-accuracy temperature measurements application note from Maxim: Many modern industrial, medical, and commercial applications require temperature measurements in the extended temperature range with accuracies of ±0.3°C or better, performed with reasonable cost and often with low power consumption. This article explains how platinum resistance […]

App note: Simple wireless temperature monitor also has dataLogging capabilities

Maxim’s application note (PDF!):  Simple wireless temperature monitor also has dataLogging capabilities: This design idea shows how you can design a simple wireless temperature-monitoring system with data-logging capabilities by using a local temperature sensor and an ASK transmitter and receiver pair.

EMRFD Direct conversion 40m receiver in a tea caddy

Flathagen has made a DIY EMRFD Direct conversion 40m receiver in a tea caddy: I woke up one day eager to build something simple (at least I thought is was simple) and opened up the first chapter in EMRFD and decided to build the 40m direct conversion receiver. I already had most of the components in […]

Fluke/Philips PM66xx frequency counter OCXO upgrade

Dan Watson documented on his blog an OCXO upgrade board he designed for the Fluke/Philips PM66xx line of frequency counters: My counter came with the standard XO timebase option, which has fairly poor specs for stability and drift. It is difficult to trim precisely with the single-turn trimmer capacitor on the board. Recently, while researching […]

Developing an IR remote and Software controller

Hardware Hacks has published a new build, a DIY Infrared remote for speaker: The idea is simple, we capture the IR signal from a remaining speaker remote and record the commands that get transmitted. We did this by connecting up our IR Receiver to the Arduino, the receiver has 3 pins and from left to right […]

Simple crystal tester

Dilshan Jayakody writes: This is simple Colpitts oscillator to test commonly available passive crystals which range between 2MHz to 27MHz. This unit must connect to an oscilloscope and/or frequency counter to get the frequency of the crystal. This circuit is design to work around 9V to 12V DC power source. Both 2SC930 transistors can replace […]

Inside card sorters: 1920s data processing with punched cards and relays

Ken Shirriff did an in-depth write-up of the punched card sorter: Punched card sorters were a key part of data processing from 1890 until the 1970s, used for accounting, inventory, payroll and many other tasks. This article looks inside sorters, showing the fascinating electromechanical and vacuum tube circuits used for data processing in the pre-computer […]