This project is an ultrasonic range finder built using the RP2040 Zero board and a 3.2-inch TFT display. It utilizes the RCWL-1655 sensor, which operates similarly to the popular HC-SR04, to measure distances ranging from 20 cm to 300 cm. The ...
A tiny DC to DC buck converter board is useful for many applications, especially if it could deliver currents up to 3 A (2 A continuously without heatsink). In this article, we will learn to build a small, efficient, and cheap buck converter ...
A while back I was challenged by a visitor to the website. He needed a very loud sweeping siren type audio sound generator powered by 3 V. He tried some of the commercial sirens but they were not very loud when powered by 3 V. He also said that ...
It is well known that a 555 timer in astable mode can be frequency modulated by applying a control voltage (CV) to pin 5. The schematic on the top of Figure 1 shows this classic 555 VCO. Modulating pin 5 has some severe drawbacks: The control ...
This two-part Design Idea (DI) follows on from a couple of previous articles relating to 100-Ω platinum resistance temperature detectors (Pt100 RTDs). The first of those (which we’ll call Ref 1 ) used a simple current-driven bridge to give an ...
The circuit uses a very inexpensive C-MOS IC that is connected to a small photodiode. Using a unique inductive feedback network, the circuit provides high sensitivity under high ambient light conditions. It is a great circuit when you want to ...
My recent DI contribution (Another silly simple precision 0/20 mA to 4/20 mA converter, Ref. 1 ) used the LM337 regulator in a novel circuit arrangement to translate an input 0-20 mA current source into a 4-20 mA two-wire transmitter current loop ...
A DC load is an essential testing tool for any electronic enthusiast, especially for testing and repairing power supplies. An adjustable DC load can limit the current at any desired level, which makes it suitable to perform various tests because ...
Recently, frequent and favorite contributor Nick Cornford gave us a cool and novel acoustic-interface design for a super sub-ohmmeter capable of audibly sniffing out defects in PWBs: “Tuneful track-tracing” ( Ref. 1 ). Figure 1’s ...
Frequent contributor R. Jayapal recently shared an interesting Design Idea (DI) for power supply control and sequencing in MCU-based applications that combine analog and digital circuitry: “Short push, long push for sequential operation of ...