About: Ibrar Ayyub

Briefly, • AC True Watts using two quadrant multiplier • Optimized for 120 VAC (can be changed) • 15 watt full scale (can be changed) • Uses DVM floating on AC Neutral as display • Requires moderately high level of analog circuit skill • Very inexpensive Find updates at:  www.projects.cappels.org Introduction I am doing some […]

Simplicity in circuitry was the design direction. Zero mass (firmware only with no physical components) would the ultimate achievement. This instrument doesn’t have any front panel controls because the user interacts via an RS-232 terminal program at 9600 baud. I needed a frequency meter for my experiments in Nondu, Thailand, where I really don’t have […]

Have you ever struggled with audio settings in control panel in middle of a VoIP call? Or, wondered if the other guy can hear you properly? I have. My work requires great deal of remote conference calls using PC. The first thing I wonder always when starting is if my audio settings — mic volume, […]

Overview After finishing Little More Serious Frequency Meter I had planned to make a suitable preamp and prescaler for it, and set about to gather ideas and parts. I was inspired by one fellow who had built the meter and the 2 line X16 character LCD display to show the output, succeeded in designing a […]

This is design for a frequency meter based on AVR microcontrollers. Maximum input frequency is specified to be 30 MHz in the multi-chip configuration, and in single-chip configuration, there are both 5 MHz and 10 Mhz versions operating with 10 and 20 MHz crystals, respectively. All versions have 9 1/2 digit resolution. I have  used […]

Its built into a plastic project box with an aluminum cover (on the bottom). The controls are as follows: Large golden knob is coarse tuning, small black knob with a blue index stripe is fine tuning, the green LED is the power on indicator, the slide switch is the on/off switch. The small black knob […]

I needed a way to measure hand-wound RF inductors in my second lab, and since I would only be doing this occasionally, I didn’t need anything fancy, and since once a friend finishes his AT90S1200-based design, I plan to make one myself, I figured I’d use this for less than a year, so I didn’t […]

A well known L/C measurement circuit is pressed into service to make a bare bones measurement circuit. Download the AVRStudio assembly source: lgm031227I.asm. Download the AVRStudio hex file: lgm031227.hex. Left-to-right: The 5 volt regulator, the LM393 oscillator (a 0.047 uf capacitor is mounted on the LC circuit connector), the AT90S2313, and the serial connector to […]

The “Battery Good” checker. When the button is pressed, the green LED will glow if the battery voltage is above the preset threshold. This version has a higher parts count than the “Battery Low” version, but a bonus is that it can drive an LED to  be very bright, and the luminance is independent of […]

1 Khz From a Quartz Crystal 1 V P-P Sine Wave Calibrated Output 1 KHz Square Wave Output 900 mv Inverted Sine Wave Output (Uncalibrated) Downloads Download the WINAVR main source for the 2313 version of the firmware: 2313sine.c. Download the complete zipped WINAVR project for the  2313 version of the firmware: 1_kHz_sine_2313.zip. Also, Download […]