A related article on this site: True RMS-To-DC Adaptor for DVM Introduction This project came about when I needed to perform some reliability tests on some headphones according to IEC 268-7. The test requires operating the headphones at their rated input power for a number of hours using clipped pink noise, and muting the noise […]
A Noise Generator per IEC 268-1, IEC 268-5, and IEC 268-7 Read More »
Take Maxim’s MAX038 function generator chip, add some frills, and you have a pretty nice tool for the bench. Downloads: Main Circuit Schematic Power Supply Schematic You can build this with switches instead of buttons if you don’t want to use a micro controller. Here is the controller code. AVRStudio 4.x Assembler Source for AT90S1200A
MAX038-Based Sweep/Function Generator With Markers using AVR ATtiny2313 microcontroller Read More »
This is a means of testing AC mains operated circuits at variable AC voltages, and it also provides isolation to allow safe measurements of that circuit. A fused isolation transformer and a variable auto transformer connected together in a grounded, fire safe box. What more could you ask? Find updates at www.projects.cappels.org Introduction
An Isolated Adjustable Auto transformer using microcontroller Read More »
Downloads Download the AVRStudio assembly source for the program: M8DPM091109A.asm Download the AVRStudio hex file: M8DPM091109A.hex Find updates at www.projects.cappels.org Overview – A 10 bit digital panel meter for positive voltage only. – Input resistance: about 130k – Ranges: 0 to 10.20 volts and 0 to 102.3 volts. – Over range indication. This project came
A 10 Bit LED Digital Panel Meter With Auto Ranging Based On The ATMEGA8 Read More »
This is a low frequency amplifier with an adjustable transimpedance that is intended to be used to take relative measurements of a wide range of photo currents. Not having many parts, this amplifier can be put together in a short amount of time. Find updates at www.projects.cappels.org Introduction I needed to make some relative optical
Photocell Amplifier using microcontroller Read More »
Measure current vs voltage or voltage vs current over limited range with good accuracy. This was built on a phenolic board which was mounted on a plastic box. The box serves two purposes: It holds the circuit off the workbench, and it makes a nice, stable mount for the potentiometer. Find updates at www.projects.cappels.org I
A SIMPLE MANUAL CURVE TRACER using microcontroller Read More »
Calculates and displays L and C from oscillation frequency using reference components. No relays, no range switching, a minimum of controls. And it is pretty accurate too! Note: After reading this article, check out the improved, modified An Even Better LC Meter… The 2 line x 16 character LCD shows the calculated inductance and the
A Pretty Good LC Meter Based on the AVR using ATTINY2313 Microcontroller Read More »
An improvement over “A Pretty Good LC Meter.” Enhanced capacitance self calibration, accurate operation without precision components, and only one micro controller. Downloads Download or view the WINAVR main source file: lcm.c Download the complete package including the LCD library: Even-Better_LCM.zip (LCD Library provided with Peter Flurey’s permission) Download Gerd Sinning’s: LCcalc tools for Windows
An Even Better LC Meter Based on the AVR ATTINY861 Read More »
This is a Minimum Mass Wireless Coupler that connects a terminal, or PC running terminal software, to other Minimum Masss Wireless devices by means of a 1200 baud data channel at 181.818 kHz. The basic Minimum Mass Wireless Coupler technology is described and links to other projects on this site that use the Minimum Mass
Wireless Coupler Terminal Interface using AVR microcontroller Read More »
Morse Code Alarm Clock Modification (Almost) Trivial application of an AT90S2313 or ATtiny2313 in an alarm clock to change the alarm from “BEEP BEEP BEEP BEEP BEEP BEEP BEEP BEEP…” to “WAKE UP” in Morse code. This was designed in response to a request and is in daily use Downloads (Updated 5 December, 2004) AVR
Morse Code Alarm Clock using ATtiny2313 microcontroller Read More »
