About: Ibrar Ayyub

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 […]

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  […]

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 […]

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 […]

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 […]

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 […]

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 […]

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 […]

Power Integrations has introduced a range of single-chip mains LED drivers for loads between 2.5 and 50W with +/-5% current regulation. Called LYTSwitch , the devices can be wired for isolated and non-isolated operation

Much as humans and other animals see via waves of visible light that bounce off objects and then strike our eyes’ retinas, radar “sees” by sending out radio waves that bounce off targets and return to the radar’s receivers. But just as light can’t pass through solid objects in quantities large enough for the eye […]