Troubleshooting and repairing Switch Mode Power Supplies

30 Awesome EEE Projects for Electrical Engineers

Engineers are always in search of projects, and finding meaningful projects makes that search worthwhile. Listed below are some electrical engineering project ideas for such engineers. A lot of them may deal in a higher power than electronics engineers are used to, hence safety first.  These hand-picked EEE projects are simple as well as interesting.

EEE Projects: Dual Axis Solar Tracker System

This system requires involvement of a wide range of engineering including mechanical electrical and electronics. The mechanical part would involve designing a smooth gear system to move as per requirement. The electrical part would be the working of solar panel and battery requirement. The electronics would involve designing the sensor system that would generate commands for the gear system to act accordingly. The system employs spur gear for the implementation of the dual axis solar tracker. The system is implemented using Atmel IC AT89C51.

This project is available at: Dual Axis solar tracker system

5V DC To 48V DC Converter For Phantom Power Supplies

This circuit presents a simple and low-cost DC-to-DC converter for phantom power supplies used in mixing consoles, microphone preamplifiers, telephone systems and similar equipment.

This project is available at: 5V DC To 48V DC Converter For Phantom Power Supplies

HVDC Power Supply Design

Circuits like Geiger counters, insect zappers, Nixie tubes and sensors require high-voltage direct-current (HVDC) supplies. There are various types of HVDC supplies available in the market, including voltage doubler or quadrupler, flyback converter and boost converter.

Some of these have low current-output capacity. But with right calculations using basic boost conversion formulae, we may achieve HVDC supplies capable of clean and high current capacity. Presented here is a boost converter design using an MC34063 DC-DC converter.

This project is available at: HVDC Power Supply Design

A simple low-power inverter circuit is described here, which converts 12V DC into 230V AC. It can be used to power very light loads like night lamps and cordless telephones, but can be modified into a powerful inverter by adding more MOSFETs.

This project is available at: Micro Inverter

Automatic Anchor Light

Federal and international regulations require boats to carry lights during sunset, sunrise and at conditions with restricted visibility. The number and colors of light vary with the size of vessel. A masthead anchor light is out of fashion as it is too high above the water level. This makes it difficult to judge the position of the boat, especially in a pitch-dark anchorage. This project is a compact yet inexpensive automatic anchor light integrated with an ambient light sensor that turns it on and off automatically.

This project is available at: Automatic Anchor light

High-Impedance Audio Buffer With JFET

The buffer circuit described here is useful in enhancing the AC input impedance of audio amplifiers used with pickups in musical instruments. Signal sources for amplifiers and passive pickups for electric guitars require very high-impedance of over 5-mega-ohm. This can be achieved easily with junction field-effect transistor (JFET) but may require special design of the printed circuit board (PCB), appropriate construction techniques of the box, proper cables and connectors. This project provides a solution for a high-impedance, low-cost, low-quiescent current, buffer-follower based on PN4393 JFET.

This project is available at: High-Impedance Audio Buffer With JFET

PIN Diode Based Fire Sensor

This is an ultra-sensitive fire sensor that activates an alarm when it detects fire. In this circuit, a sensitive PIN diode is used as a fire sensor for longer-range fire detection. It detects visible light and infrared (IR) in the range of 430 nm – 1100 nm. Visible light and IR from the fire activate the sensor to trigger the alarm. It also detects sparks in the mains wiring and if these persist, it gives a warning alarm. The anode can easily be identified from the top-view flat surface of the photodiode. A small solder point to which a thin wire is connected is the anode and the other one is the cathode terminal.

This project is available at: PIN Diode Based Fire Sensor

Plus-Minus 5V Supply From 9V Battery

Op-amps require dual-polarity supply for proper operation. When working with battery supply, it becomes difficult to get dual power supply for the op-amps. Presented here is a simple circuit that provides ±5V from a 9V battery. This is one of the interesting projects among Electrical Engineering Project Ideas. Op-amps require dual-polarity supply for proper operation. When working with battery supply, it becomes difficult to get dual power supply for the op-amps.

This project is available at: Plus-minus 5V Supply From 9V Battery

Infrared Motion-Sensing Relay Switch

This project is designed for use with all kinds of medium-power automobile/domestic 12V DC loads. It is a simple solid-state relay (SSR) switch, controlled by a standard passive infrared (PIR) motion sensor module. A PIR sensor is an electronic device that can measure IR light radiating from objects in its field-of-view. Apparent motion is detected when an IR source with one temperature (such as a human being) passes in front of an IR source with another temperature (such as a wall). The PIR sensor module, centred on a PIR sensor, has elements made of crystalline material that generates an electric charge when exposed to IR radiation.

This project is available at: Infrared Motion-Sensing Relay Switch

Low-cost LPG Leakage Detector

The circuit for an LPG leakage detector is readily available in the market, but it is extremely expensive and usually based on a microcontroller (MCU). This project presents a low-cost circuit for an LPG detector that you can build easily. The main objective of the circuit is to detect LPG leakage anywhere. At the heart of the circuit is dual comparator IC LM393 (IC2). It is used to compare two different voltages, in this case, reference voltage and MQ-6 gas sensor output voltage.

This project is available at: Low-Cost LPG Leakage Detector

Low-Cost Dusk-Dawn Controller

This dusk-dawn controller is built around a light-dependent resistor among other components. The common battery supply is used for operating the circuit as well as for load, that is, for power LED/small inverter circuit. Resistors work as voltage divider and current limiter in the circuit. LEDs are used as circuit deactivation indicator. An n-channel MOSFET is used for the switching action of an LED light.

This project is available at: Low-Cost Dusk-Dawn Controller

Auto Power Switching Mains, Solar Inverter or Generator

This project is based on the AEIOU heuristic framework of Design Engineering Approach. Design for Performance, Safety and Reliability is ensured in terms of switching module. Design for Ergonomics and Aesthetics is ensured in terms of Priority set by the user regarding the availability of Power Source. Design for Manufacturability and Assembly is ensured in terms of Generator, Inverter and Solar Plates. Also, based upon choice and availability, different circuits using Eagle can be worked upon.

This project is available at: Auto Power Switching Mains, Solar Inverter or Generator

Signal Generator and Inverter Using NE555 Timers

Often we require a squarewave signal generator with adjustable frequency, almost equal high and low output pulses and adjustable amplitudes. Here we present a simple, useful and low-cost signal generator built around NE555 timers. Using external switches, you can control or select frequency ranges as per your requirements.

This project is available at: Signal Generator and Inverter Using NE555 Timers

Configurable RS232 to TTL to I2C Adapter

RS232 signals cover a much longer distance than standard TTL and I2C signals. These signals have better noise immunity as well. RS232 is a well-known standard supported by many popular ICs and therefore is still widely used. Sometimes we want to send TTL and I2C signals over a longer distance. This project describes how these signals can be extended through RS232 lines.

This project is available at: Configurable RS232 to TTL to I2C adapter

Vibration Activated Smart CRO Probe

This is a simple, low-cost, energy-saving and device-saving circuit for an electronics lab, service centre, electronics workshop, or wherever a CRO is in use. Generally, in a repair station, a CRO is used for a very short time. But in most cases, the user fails to switch off the CRO immediately after use. The service engineer mostly concentrates on faults rather than noticing whether the CRO is on or off. A vibration sensor turns the CRO off when the probe is idle for a specified amount of time.

This project is available at: Vibration Activated smart CRO probe

Electrical Engineering Project Ideas: 4 channel multi mode audio amplifier

Sometimes we need configurable multichannel amplifiers for experiments or for use in offices or schools. Here is a project based on TDA1554Q, configured for multi-mode function with four channel outputs. It has four channels and each channel can provide around 11W over a load of 2-ohms and around 6W over a load of 4-ohms. The circuit will also work with loads of 4-ohms to 16-ohms. Gain of each channel is fixed at 20dB in single-channel mode and 26dB in BTL mode.

This project is available at: 4 channel multi-mode Audio amplifier 

Design and analysis of single-stage amplifier using C++

Many formulae are required to calculate the parameters involved in a circuit of a transistor based audio amplifier. Some of these values involve resistors, coupling capacitor, bypass capacitor, power consumption, the current flowing through different components. A good amount of time is required to calculate such parameters even with a regular calculator. Using C++ program, all the parameters can be calculated in a fraction of a second. This project presents a single-stage transistor audio amplifier that requires a total of 19 formulae to obtain the values of components and analyse the circuit.

This project is available at: Design and Analysis of Single stage Amplifier using C++ 

Four-channel video and audio sequencer

This next project is a simple circuit for switching your CCTV camera outputs sequentially. It switches four video and audio channels sequentially, one at a time. It is built around a 555 timer few other components. The timer is configured as an astable multi-vibrator. A single-side PCB of the four-channel video and audio sequencer is provided along with the component layout. After assembling the circuit on the PCB, enclose it in a suitable plastic box.

This project is available at: Four channel video and audio Sequencer

Automated USB controlled power switch

Power for TV and set-top box (STB) is derived from a common switchboard. The switched-mode power supply (SMPS) of the TV continues to draw a small amount of power from mains and the STB is not switched off when you switch off the remote. This next project presents a circuit that can control the mains power of an LED TV and the DTH STB. It also protects the devices from harmful initial surges when power comes back after a power failure.

This project is available at: Automated USB controlled Power Switch

1kW sine wave inverter

An inverter provides power backup for mains-based appliances in the event of a power failure. Most of the inverters available in the market have a complicated circuit design and are not very economical. Some of them produce a square-wave output, which is undesirable for inductive loads. This project presents a simple inverter circuit that produces 50Hz quasi sine-wave output using a single IC CD4047 and some discrete components making it a very cost-effective solution.

This project is available at: 1kW sine wave Inverter

Four frequency generator

There is a need for TTL and CMOS signals by stable frequency sources for development, testing and maintenance of digital and analogue electronic circuits. These sources are also useful for fast checking of oscilloscopes, probes, multimeters, frequency metres and other measurement equipment. This project proposes a circuit that produces fixed frequencies of 4MHz, 6MHz, 10MHz and adjustable square-wave with variable frequencies from around 10Hz to more than 100kHz.

This project is available at: 4 Frequency Generator

Programmable 3 Phase Controller For ON/OFF Motor

A programmable time switch is useful in designing an automatic on/off controller for 3 phase electric motor. This next project proposes a system with two programmable time switches for setting the starting and stopping times of the motor. Two control circuits interface with the start/stop switches of the 3-phase motor starter. There is provision for setting days of the week for the controller to function as well.

This project is available at: Programmable 3 phase Controller for ON/OFF motor 

Wireless Power Transfer

The main objective of this project is to develop a system of wireless power transfer in 3D space. The air core transformer operating near 40 KHz is the main concept for wireless power transfer, as one cannot transfer 50 Hz ac power by air core. The secondary coil in resonance develops a voltage of 40 KHz at about 12 volt when it is taken over the primary coil. The output of this secondary is given to a 10 watt lamp that glows at considerable distance from the primary coil.

This project is available at: Wireless Power Transfer In 3d Space 

High Power LED Stroboscope

Stroboscope is a convenient and accurate enough instrument to measure speeds of rotating objects in homes or industries. One can use it to find the speed of fans, motors or any other rotating object. It is a flashing light that provides sharp light pulses at a variable rate. An object rotating with frequency matching the pulsed light is observed as stationary.

This project is available at: High Power LED Stroboscope

Password Based Circuit Breaker

A circuit breaker protects electrical circuits from damage n case of overload or short circuit. Its basic function is to detect a fault condition and interrupt current flow. The system uses an 8 bit microcontroller of 16f877A family. An EEPROM stores the password and is easily changeable. The password is entered through a keypad and a relay opens or closes the circuit breaker, which is indicated by a lamp.

This project is available at: Password based circuit breaker

Over/Under Voltage Protection of Electrical Appliances

Presented here is an under/over-voltage protection circuit that protects refrigerators as well as other appliances from under & over-voltage.  Operational amplifier IC LM324 (IC2) is used here as a comparator.

This project is available at: Over/Under Voltage Protection of Electrical Appliances

DC Panel Meter using Arduino

Panel meters in regulated power supplies are used to display electrical parameters like voltage and current. Presented here is a circuit to display DC voltage and current of power supplies, including DIY-type ones.

This project is available at: DC Panel Meter using Arduino

Multi-Status Indicator Using Single RGB LED

Monitoring circuits in battery chargers, water-level indicators, etc use LEDs to indicate the status of certain conditions. Presented here is a multiple status indicator circuit that uses a single RGB LED for seven different indications.

This project is available at: Multi-Status Indicator Using Single RGB LED

Simple Low Power Inverter

Here is a simple low power inverter that converts 12V DC into 230-250V AC. It can be used to power very light loads like window chargers and night lamps, or simply give shock to keep the intruders away. The circuit is built around just two ICs, namely, IC CD4047 and IC ULN2004.

This project is available at: Simple Low Power Inverter

Power-Saving Relay Driver

n many circuits, the switching action is performed by a relay, which in turn activates an external load. The power consumed by the relay may be unsuitable for battery-powered applications. Here is a simple solution using some inexpensive components to considerably save power.

This project is available at: Power-Saving Relay Driver

Linear Timer For General Use

This simple linear timer can be used to control any electrical appliance that needs to be switched off after a certain time, like a small heater or a boiler, provided the relay-switch parameters meet the requirements of that appliance. It uses low-cost components and combines digital precision with simple analogue control. This provides long timing durations without the use of high-valued resistors or capacitors.

This project is available at: Linear Timer For General Use

Hope these electrical engineering project ideas were useful to you. If you have more such interesting electrical engineering project ideas feel free to post it in the comments section below.

This article was first published on 18th October 2016 and was recently updated on 5 February 2020.

This content was originally published here.

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