Pocketable Nano Alert Alarm

If you want to alert someone nearby to a situation, especially a dangerous or unpleasant situation, this Arduino Nano microcontroller based pocketable alert alarm will help you!

Below is the wiring diagram of the 9V battery powered Nano Alert Alarm (click to enlarge).

Here is the list of parts:

• Arduino Nano v3 x1
• 5V Passive Buzzer (Piezo Speaker) x1
• 5mm Red LED x1
• 150Ω Resistor x1 (optional - or just use a zero-ohm jumper)
• 470Ω Resistor x1
• 470uF/16V Electrolytic Capacitor x1
• Push Button Switch (NO) x1
• 9V 6F22 Battery x1

The Arduino Sketch of this project is pretty simple and straight forward (see below).

int ledPin = 13; //LED Pin

int inputPin = 8; //Alarm Button Pin

int pinSpeaker = 9; //Passive Buzzer Pin

int val = 0;

void setup() {

  pinMode(ledPin, OUTPUT);

  pinMode(inputPin, INPUT_PULLUP); //Internal Pullup Enabled

  pinMode(pinSpeaker, OUTPUT);

  }

void loop() {

  val = digitalRead(inputPin);

  if (val == LOW) {

    digitalWrite(ledPin, HIGH);

    playTone(300, 160);

    delay(150);

  } else {

    digitalWrite(ledPin, LOW);

    playTone(0, 0);

  }

}

// duration in mSecs, frequency in hertz

void playTone(long duration, int freq) {

  duration *= 1000;

  int period = (1.0 / freq) * 1000000;

  long elapsed_time = 0;

  while (elapsed_time < duration) {

    digitalWrite(pinSpeaker, HIGH);

    delayMicroseconds(period / 2);

    digitalWrite(pinSpeaker, LOW);

    delayMicroseconds(period / 2);

    elapsed_time += (period);

  }

}

In Arduino, the tone() function generates a 50% duty cycle square wave of the specified frequency on a pin. A duration can be specified, otherwise the wave continues until a call to noTone().

That pin then can be wired to a small piezo buzzer or piezo speaker to play tones.

What is the function of playTone?

• playTone(a,pin,frequency,duration) plays a tone on a piezo speaker attached to the digital pin on Arduino at the specified pin and frequency for the specified duration.
• playTone(a,pin) plays a tone on a piezo speaker attached to the digital pin on Arduino.
• playTone(a,pin,frequency) plays a tone on a piezo speaker attached to the digital pin on Arduino at the specified pin and frequency.

Syntax

• playTone(a,pin,frequency,duration)
• playTone(a,pin)
• playTone(a,pin,frequency)

For more details, see this official Arduino page!

That's it for now. Gather the necessary parts and set up your own pocketable Nano alert alarm.

The pocket alert alarm (personal safety alarm) can be carried in a pocket, purse, or attached to a belt so that it can be used in an emergency situation to call for help, draw attention to an unsafe situation, or to scare off an attacker.

Simply push and hold the alarm button and the alarm will sound and the light will flash.

Finally, test your alarm periodically and replace the battery as needed. Cheers!

An Ultimate Guide to Setting Up Your Own Home Electronics Lab

Setting up your own professional electronics lab at home can be a game-changer for any electronics enthusiast or hobbyist.

Quick Introduction

Having a dedicated space equipped with the right tools and equipment can significantly enhance your ability to work on projects, experiment with new ideas, and learn more about electronics.

Whether you are a beginner looking to get started or a seasoned professional looking to take your skills to the next level, this ultimate guide will provide you with everything you need to know about creating your own electronics home lab or workbench.

From essential tools and equipment to tips on organization and safety, this guide has got you covered.

OK, let's dive in and turn your home into a hub for innovation and creativity in the world of electronics.

The importance of a professional home electronics lab

A professionally set up electronics lab at home offers a myriad of benefits that can elevate your projects and experiments to a whole new level.

Having a designated space allows for better organization, efficiency, and concentration, enabling you to focus on your work without distractions.

With the right tools and equipment at your fingertips, you can seamlessly transition between tasks and tackle complex projects with ease.

Additionally, a well-equipped home electronics lab promotes safety by providing a controlled environment for handling sensitive components and conducting experiments.

By investing in a professional electronics lab, you are investing in your passion for electronics and setting yourself up for success in your endeavors.

Essential equipment for your home electronics lab

Equipping your professional electronics lab with the right tools is crucial for optimal performance and productivity.

Essential items to consider include a high-quality soldering station, digital multimeter, oscilloscope, bench power supply, and a reliable workbench with ample storage space.

These tools form the foundation of a well-functioning lab and enable you to undertake a wide range of projects efficiently.

Investing in quality equipment not only ensures accurate results but also enhances your overall experience in the lab.

Stay tuned as we delve deeper into each essential item and explore the key features to look for when selecting the best tools for your setup.

Setting up your workspace for safety and efficiency

Setting up your workspace for safety and efficiency is paramount when creating your own professional electronics lab.

Ensure adequate lighting, proper ventilation, and organization of tools and components for easy access.

Implementing safety measures such as wearing protective gear, organizing cables, and labeling hazardous materials are crucial steps to maintain a safe working environment.

Also, utilize cable management solutions and invest in quality ergonomic furniture to optimize productivity and prevent strain injuries.

Stay tuned for expert tips on creating a workspace that enhances your workflow and promotes a safe and efficient lab environment.

Organizing and managing your inventory

Efficiently organizing and managing your inventory is key to running a successful electronics lab.

Keep track of your components, tools, and supplies by utilizing storage solutions like bins, shelves, and cabinets. Implement a labeling system to easily identify and locate items when needed. 

Regularly conduct inventory checks to replenish supplies and eliminate clutter.

Consider using inventory management software to streamline the process and ensure you have all the necessary items for your projects.

A well-organized inventory not only saves time but also improves workflow efficiency in your professional electronics lab.

Stay tuned for more expert advice on optimizing your workspace for maximum productivity.

Developing testing and troubleshooting procedures

Once your inventory is well-organized, it's crucial to establish testing and troubleshooting procedures in your electronics lab.

Create standardized checklists for testing components and circuits to ensure accuracy and efficiency in your projects.

Familiarize yourself with various testing equipment and techniques to quickly diagnose and resolve issues.

Document your procedures and results to track your progress and improve your troubleshooting skills over time.

By developing systematic testing and troubleshooting procedures, you'll be better equipped to handle challenges that arise during your electronics projects.

Stay tuned for more insights on optimizing your home electronics lab for professional-grade work.

Networking with other professionals in the field

Networking with other professionals in the field is essential for growth and learning in your home electronics lab.

So, join online forums, attend virtual workshops, and participate in industry-related events to connect with like-minded individuals.

Engaging with others in the field can provide valuable insights, collaboration opportunities, and guidance on advanced techniques.

Building a strong professional network will not only enhance your skills but also open doors to potential career advancements or collaborative projects.

Stay proactive in expanding your network to stay updated on the latest trends and technologies in the electronics industry.

Continuing education and staying current with industry trends

Staying relevant in the rapidly evolving electronics industry requires a commitment to continuous learning and keeping up with the latest trends.

Investing in continuing education programs, online courses, and workshops will ensure you stay ahead of the curve in your home electronics lab.

By staying current with industry advancements, you not only enhance your skills but also increase your credibility within your professional network.

Make it a habit to regularly read industry publications, subscribe to relevant newsletters, and follow key influencers to stay informed.

Embrace a mindset of lifelong learning to adapt to new technologies and stay competitive in the electronics field.

In Conclusion

Investing in your own professional home electronics lab is not just a hobby-it is a strategic decision that will benefit your career in the long run.

By continuously upgrading your skills and staying informed about industry trends, you are positioning yourself as a valuable asset in the electronics field.

Setting up a well-equipped lab at home provides you with a practical space to experiment, innovate, and bring your ideas to life.

Remember, the key to success lies in your commitment to lifelong learning and staying ahead of the curve.

Embrace the journey of creating your own professional electronics lab, and watch as it opens up new opportunities for growth and advancement in your career. Good luck ⪫

(This is a Copyright-Free AI-generated Content)

Alternating LED Flasher

We came across a bunch of simple and cheap LED flasher kits at a surplus sale fair recently.

The Alternating Dual-LED Flasher Kit shown here is from Kemo Electronic GmbH.

This do-it-yourself hobby electronics kit is a 2-LED alternating flasher.

In this little kit, two differently colored light emitting diodes (LEDs) will flash alternately.

The flashing speed of the LEDs (flashing velocity) is adjustable through a small onboard potentiometer. 

A 9V battery is required to run the kit.

Naturally this inspired us to go back to the basics of simple LED flasher circuits based on common transistors, because it is not only fun, but also a good learning experience for many beginners and students.

Now you can use a small perfboard to build your own alternating light emitting diode flasher.

Here is its circuit diagram (click to enlarge):

See the list of suggested components below.

• D1: 1N4007 Diode
• C1: 100uF/25V Electrolytic Capacitor
• LED1: 5mm or 10mm Red LED
• LED2: 5mm or 10mm Yellow LED
• T1 & T2: BC547 NPN Transistors
• C2 & C3: 10uF/25V Electrolytic Capacitors
• P1: 20KΩ Trimpot
• R1 & R4: 620Ω Resistors
• R2 & R3: 33KΩ Resistors

Note that these part numbers are not very critical. Therefore you can change the values of the resistors and capacitors (R1-R2-R3-R4 and C2-C3) to alter the flashing velocity and/or the operating voltage.

This LED flasher can be used in flashing adornments, nameplates, signboards, miniature toys, models etc. 

Although a 9V battery is preferred, it will work from any 6 to 12V dc power supply. The total power consumption at 9V dc input is around 20mA only.

The little circuit is called an astable multivibrator (AMV) as it does not remain in one of its two well-defined states.

That is, the circuit oscillates between one of two states where the right LED only lights up when the right transistor is active. Likewise, the left LED turns on whenever the left side transistor is active.

So, the circuit switches between these two states to an indefinite extent as long as it is powered!

Using the same values for C2 and C3 and R2 and R3 results in symmetric on and off times for both LEDs.

In principle, you can work out the on/off times of the LEDs (T) by using the formula:

T = R x C = 33KΩ x 10uF  =  33000Ω x 0.00001F  = 0.33s (neglecting the potentiometer's resistance).

So, each LED in this circuit will stay on and off for approximately 0.33 second.

OK, now you have a simple alternating flasher circuit which is a fantastic project for getting started with electronics engineering.

Not to mention it comprises only a handful of commonly available and inexpensive components.

The circuit might seem trivial at first, but upon closer inspection, it introduces a fantastic playground for figuring out and practicing computations in real-world electronic circuits. Have fun!

Avalanche Transistors

Avalanche transistors are semiconducting devices that utilize the avalanche breakdown principle!

Avalanche breakdown is a unique phenomenon that occurs when a high voltage is applied to a p-n junction, to switch from an off state to an on state.

Avalanche transistors are broadly used in various high-voltage and high-frequency electronic circuits like:

• Fast (High-Speed) Pulse Generators
• Microwave Frequency Generators
• Laser Diode Drivers for LIDARs
• Fast Edge Switch Generators...

Avalanche transistors are similar in structure to conventional bipolar junction transistors (BJTs), consisting of three layers of semiconductor material that form two p-n junctions. These layers are known as the Emitter, Base, and Collector.

The working of an avalanche transistor is characterized by the breakdown of the collector-base junction. When the voltage across the collector-base junction exceeds the breakdown voltage, the transistor rapidly switches from off to on, allowing a large current to flow.

Nowadays, Avalanche Transistors specifically designed for low voltage Avalanche Mode operation is also available from various vendors. The FMMT411 NPN Avalanche Transistor, available in SOT23 SMD package, is a good example (click below image to enlarge).

Even for an electronics student or hobbyist, fast pulses are sometimes required when measuring slew rate or propagation delay, and for sampling. In such cases, an avalanche transistor circuit can be used to generate pulses with sub-nanosecond rise and fall times.

Avalanche transistor applications in the hobby electronics world was made popular following the application note -A Seven-Nanosecond Comparator for Single Supply Operation - by analog guru Jim Williams.

Many people have built such avalanche pulse generators for practical applications like oscilloscope bandwidth measurements.

It's worth noting that using a fast-rising pulse to measure rise-time leans to render too affirmative rise-time estimates because the pulse may not have reached its peak before falling off due to the short pulse width and the limited bandwidth of the oscilloscope under test.

If you'd like to build another Avalanche Pulse Generator yourself, you will get a simple build idea through an article scheduled to be posted here in a few weeks. Anyone else interested?

Self-Defense LED Strobe Light Build Idea

Strobe Lights are widely used to temporarily blind and disorient targets. Do you need a strobe light for self-defense? 

This post explains the construction of a quick-and-easy microcontroller-based strobe light!

The idea is centered around the commonly available and cheap Digispark ATTiny85 Development Board but almost all Arduino Uno/Nano microcontroller boards works equally well here.

This is the schematic (click to enlarge):

The hardware setup is pretty simple so you can rig it up within a couple of minutes.

The P1 I/O of Digispark (U1) is configured as an output pin to drive an LED through a N-channel logic-level power Mosfet IRL520N (Q1). The next I/O is wired to the wiper of a 10K potentiometer (P1). This potentiometer lets you switch and control the LED in a convenient way - from fully off to fully on, and strobe effect (~ 2Hz to 25Hz) in between. The slide switch (S1) is the master power on/off switch.

The Digispark board has an onboard 5V fixed voltage regulator chip (78M05), so you can safely apply a DC voltage in 7.4V to 14.8V range through its VIN pin header (the onboard voltage regulator might work anywhere from about 7V to 35V, though at 35V it would overheat the voltage regulator chip very quickly).

This is the schematic of the Digispark ATTiny85 Microcontroller Development Board (click to enlarge):

This is the Arduino-Style Sketch (Code):

[code]

int driveLamp = 1; // Lamp Drive O/P = P1

int val = 0;

int onTime = 0;

int offTime = 0;

void setup() {

pinMode(driveLamp, OUTPUT); //P1 as O/P

}

void loop() {

val = analogRead(1); // Potentiometer I/P = P2

onTime = val;

offTime = (-2000000 / (onTime + 1000)) + 2000;

onTime = onTime / 4;

offTime = offTime / 4;

if (onTime > 12) {

digitalWrite(driveLamp, HIGH); }

delay(onTime);

if (onTime < 250){

digitalWrite(driveLamp, LOW); }

delay(offTime);

}

[/code]

The code simple and moderately straight forward.

Basically, it’s simply coded to turn the LED drive pin (P1) on and off with delays in between set by the travel of the potentiometer (P1) which’s directly linked to the A1 (P2) analog input of the tiny microcontroller.

This circuit is able to drive most discrete LEDs and special LED modules.

But remember, after connecting an LED (together with its optical parts, if any), you may have to employ additional electronics demanded by the light source (and/or the power source) chose for your particular application.

We used a 12VDC pink LED module to test our experimental 12VDC breadboard setup - it worked nice!

Finally a word of advice: For most people with epilepsy, exposure to strobe/flashing lights at certain intensities or to certain visual patterns can trigger seizures.

This condition is known as Photosensitive Epilepsy which's more common in children and adolescents!

That’s it. We hope you found this post informative and helpful!

Water-Cooled Breadboards

From Wikipedia, A breadboard, solderless breadboard, or protoboard is a construction base used to build semi-permanent prototypes of electronic circuits.

Unlike a perfboard or stripboard, breadboards do not require soldering or destruction of tracks and are hence reusable.

For this reason, breadboards are also popular with students and in technological education.

A variety of electronic systems may be prototyped by using breadboards, from small analog and digital circuits to complete central processing units (CPUs).

OK, this post is a quick introduction to water-cooled breadboards, which may be a little unfamiliar to many beginners and hobbyists!

Thorlabs' Water-Cooled Breadboards are versions of their anodized aluminum breadboards that have been plumbed to accept a water or coolant supply.

They feature a standard 1" (25 mm) hole pattern and are ideal for applications involving sensors, detectors, lasers, LEDs, or other apparatuses that may require temperature stabilization.

These water-Cooled breadboards can be used in applications requiring cooling or heating.

• Cool or Heat Work Surface via Internal Water Channels (0 to 60 °C)
• Matte Black-Anodized Finish Reduces Reflections
• Through-Tapped Mounting Holes

Below is the image of Throlab's MBC3030/M Water-Cooled Breadboard (300 mm x 300 mm x 12.7 mm, M6 Taps).

More details, drawings, and documents are available. Click Here → MBC3030/M

Maybe we will go into this a little more in a later post. See you then!

Electronics Blog Update!

Dear Readers & Visitors...

As you know, this electronics blog started a few years back.

But due to our busy professional schedules and some other reasons beyond our control, we were not able to satisfy you with valuable contents till now.

At this moment, we are extremely happy to announce that we are now back on track with the support of a few veterans around us.

So, from now you can see awesome technical (especially electronics) content here. Our blog posts are scheduled to be posted every Tuesday and/or Saturday.

• CIRCUITS
• DESIGN IDEAS
• REVIEWS
• PROJECTS
• TEARDOWNS
• TUTORIALS
• INTERVIEWS

& More interesting things to come... Stay Tuned...

Thank you for your valuable cooperation till date. Looking forward to your continued support.

It is often the small steps, not the giant leaps, that bring about the most lasting change!

--Team electroTEKSNiX 

Sharp Optical Dust Sensors

The GP2Y1010AU0F and GP2Y1014AU0F from Sharp are the most common and widely used optical air dust sensors tailored for sensing dust particles.

An infrared emitting diode (IRED) and a phototransistor are diagonally arranged into these devices, which allows detection of the reflected light of dust in air. It is very effective in detecting very fine particles like the cigarette smoke.

These Sharp products are probably true for all the cheap (i.e. hobbyist) optical dust sensor using the infrared light scattering technique. The sensor module has a 6-pin connector and the electronic inside the shell is split in two parts, the IRED (emitting part) and the phototransistor (receiving part).

The provided analog output is proportional with the concentration of the dust particle in the air.

See the DATASHEET

Geiger-Muller Tube - Mullard ZP1481

The Mullard ZP1481 Geiger-Muller Tube is a halogen quenched metal tube with a thin end window!

It is used for detecting alpha, beta and gamma radiation and is recommended as a general purpose tube for use with radioactive sources in schools.

A removable protective mesh cap of plastic is fitted over the window and the body has a thin plastic coating.

Mullard ZP1481 Features:

• Sensitive to alpha, beta and gamma radiation
• Threshold voltage: max. 400V
• Plateau length: min. 100V
• Recommended supply voltage: 450V
• Operating temperature: -40 to +75°C
• Dead time (at 450V): 120μs
• Anode/cathode capacity: 3.5pF
• Sensitivity for 1mR/L radium: 1650 counts min-1
• Window thickness: 2.5 - 3.0 mg cm-2
• Dimensions overall: 76mm x 26mm diameter
• Life expectancy at approx. 25°C: 5x10¹° counts

An appropriate Geiger-Muller Tube Holder is essential to start experimenting with this GM Tube. Usually GM Tube Holders are sold separately.

This post is based on information found at https://www.findel-international.com/ 

And, below is the link to get more details about Mullard ZP1481

https://www.findel-international.com/product/science/physics/atomic-structure/geiger-muller-tube-mullard-zp1481/e8a49724

According to Wikipedia, The Geiger–Müller tube or G–M tube is the sensing element of the Geiger counter instrument used for the detection of ionizing radiation.

It is named after Hans Geiger, who invented the principle in 1908, and Walther Müller, who collaborated with Geiger in developing the technique further in 1928 to produce a practical tube that could detect a number of different radiation types.