Power Buzzer

How often on average do you have to call members of your family each day to tell them that dinner is ready, it’s time to leave, and the like? The person you want is usually in a different room, such as the hobby room or bedroom. A powerful buzzer in the room, combined with a […]

Cash Box Guard

Most thefts happen after midnight when people enter the second phase of sleep called ‘paradoxical sleep.’ Here is a smart security circuit for your cash box that thwarts the theft attempt by activating an emergency beeper. The circuit can also be used to trigger any external burglar alarm unit. The cash box guard circuit (shown […]

Salt Taster Circuit Diagram

Detects the amount of salt contained in liquid foods, Three-level LED indicator This circuit was designed to detect the approximate percentage of salt contained in a liquid. After careful setting it can be useful to persons needing a quick, rough indication of the salt content in liquid foods for diet purposes etc. IC1A op-amp is […]

Mapping Defects on Integrated Circuits

Mapping Defects on Integrated Circuits The Challenge: Creating a system to localize failure mechanisms causing abnormal electrical behavior, including those linked to complex parameters (such as frequencies, amplitudes, and digital values contained in registers), in integrated circuits (ICs). The Solution: Improving a conventional faults mapping system using NI PXI hardware and the NI LabVIEW FPGA […]

Optimizing Circuit Performance

Optimizing Circuit Performance National Instruments introduces Multisim 12.0 with specialized editions for circuit design and electronics education. Multisim 12.0 Professional Edition is based on industry-standard SPICE simulation and optimized for usability. Engineers can improve design performance to fit their applications by minimizing errors and prototype iterations with Multisim simulation tools that include both customizable analyses […]

Plants Watering Watcher-2

Schematic Parts List: IC1 ……. CD74HC132 R3 ………. 3.9M B1 ……… Two AAA alkaline cells, with holder R5, R6 ….. 680 C1, C3 … 1nF (0.001uF) or 2.2nF (0.0022uF) R7 …….… 15 C2 ……… 100uF/16V electrolytic R8 …….… 47K C4 ……… 220nF (0.22uF) D1 …….… 1N4148 or 1N914 R1 ……… 470K (all resistors 1/4W, 5%) […]


This is a great intercom circuit that can be used in many ways. It uses 22V to operate and maybe it will work at a lower voltage (you can try it). For input/output it uses a loundspeaker (20-45 Ohm) on each side. Click to enlarge Componets Layout PCB Parts List R1: 2,2 M C6: 200uF/40V […]


Turn ON or OFF electrical devices using remote control is not a new idea and you can find so many different devices doing that very well. For realization of this type of device, you must make a receiver, a transmitter and understand their way of communication. Here you will have a chance to make that […]

Unusual clock with AT89C2051

Why unusual clock? Strangeness of this clock is in its expression of numbers, which is realized using seven Leds. Leds are located inside a pipe, one above another and if we move Leds enough fast left or right, we have a space where we can write numbers, characters or anything else. All these are possible […]