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Electronics base: LEDs, resistors, transistors, microchips and others

Hi everyone! In this article i tell you about basic electronic components – LEDs, resistors, transistors, capacitors and microchips. You will read base information about this component, who are they and what they can do. Let’s go =)

Introduction into electronics

Electronic devices are around us every day – from smartphones to smart houses and electric cars. If you know the basics of it, you can make your own electronic devices. In this article we will talk about the main components – LEDs, resistors, transistors and microchips – and we will learn how to use them in our projects and schemes.

Basic electronic components

1. Resistors

Permanent resistors, these are 510 Ohms

Resistors — components for decreasing Ampe power in circuit. Used for safe small components, which needed little Amper power, for example, LEDs, or for making signal.

How do resistors work?

  • Ohm rule: V=I×RV=I×R, where VV — voltage, II — current, RR — resistance.
  • Example: If to the resistor 100 Ohms applied 5 V, the current will be I=5 V/100 ohms=0.05 AI=5V/100 ohms=0.05 A.

Types of resistors:

Changeable resistor – potentiometer, 10 kOhms.
  • Permanent: fixed resistance (for example, 220 Ohms or 10 kOhms).
  • Changeable: potentiometers, for change volume or brightness.

Color marking of resistors:

ColorMeaning
Brown1
Red2
Orange3
……

Advice: I recommend to use special calculators for counting resistance of concret resistor by color mark – for example, with my own calculator.

2.LEDs (Light Emitting Diode): Light and color for your projects

LEDs convert electricity to light with high effectivity.

Features of work:

  • Polarity: Anode(+, long contact, input) and cathode (-, short contact, output). Wrong connecting of power to the LED will destroy it.
  • Power: Usually 1.8–3.3 V needed for LED, it can vary from the color of your LED – blue, green and white colors needed 3-3.3V. Red, yellow and orange colors needed 1.8-2V. It’s important to apply a little Amper power – not more than 15-20 mA (0.015-0.020 Ampers). You can apply also 5 V, but Amper-power must be very little – 5-10 mA.

Calculating resistor for LED:

Usually, for LEDs are used 300-1000 Ohms resistors in Arduino, but, how more is Ampre-power in your circuit, applied to LED, the resistor must be more powerful. If resistance of the resistor will be very large, your LED will light not bright.

Formula for calculating the resistance of a resistor: R – resistance of the resistor, A – power voltage (V), B – needed voltage for LED, C – Amper-power in circuit (Ampers, not milliAmpers. 1 Amper = 1000 mAmpers).

Формула расчёта сопротивления резистора: R – сопротивление резистора, A – напряжение питания (V), B – необходимое питание для светодиода (V), С – сила тока в цепи (Ah).

R = (A−B) / C

You can use my calculator here.

Used in:

  • Indication – usually are used small and unpowerful LEDs, only for color indication. For example, on Arduino board indication LEDs are ON, TX and RX.
  • Light – usually are used bigger an powerful LEDs, for more light,. Usually the are white color. For example, LED headlights in cars, projectors and flashlights.
  • LED-matrix – are used indication LEDs for view any information on group of LEDs. For example, seven segment displays, 8*8 LED matrix and other.

3. Transistors: Amps and switches

Transistors can control strong power with a little signal.

Basic types of transistors:

  1. Bipolar (BJT):
    • NPN and PNP. Controls BASE power.
    • Example: 2N2222 (NPN) for motor control.
  2. Polar (FET):
    • Are controlled by power on TRIGGER (for example, MOSFET IRF540).

Example circuit:

Base → Resistor (for safe) → Control signal (Arduino)  
Collector → Power (motor, LED, lamp)  
Emitter → GND

4. Microchips: “brain” of electric circuits

Integral schemes (IS) contain thousands of components in a miniature box.

Popular microchips types:

  • Analog: operation uppers (LM741), power stabilizators (LM7805, AMS1117).
  • Digital: Logical elements (AND, OR), microcontrollers (Arduino UNO/NANO/PRO MINI – ATMEGA328P, ESP32).
  • Combined: Timer NE555 (signal generation).

Example of using NE555 timer:

Blinking LED or stroboscope:

  1. Connect capacitor and resistor to the timer to set frequency of blinking.
  2. The output of the timer controls LED.

5. Other components

  • Capacitors: Collecting power, filtration (electrolitic, ceramic).
  • Diodes: One-way conductivity (convert variable power to polared).
  • Relays: Electric-mechanical switches for control strong power (control 220V with Arduino and relay).

Practical advices

  1. Soldering and breadboard: Start from breadboard for prototyping.
  2. Multimeter: Measure voltage, current, and resistance. Multimeter is must-have if your hobby is electronics.
  3. Safety: Don’t change circuit components, when it is connected to power.

Ending

Once you have learned the basic components, you’ll be able to create complex devices from automated lighting fixtures to robots. Experiment, use simulators (for example, Tinkercad or Wokwi), and don’t be afraid of mistakes!

FAQ

Q: How to select resistor’s resistant for LED?
A: Use formula R=(Vpower−VLED)/ILEDR=(Vист​−VLED​)/ILED​. Usually, if voltage in circuit is 5 volts on Arduino or 3.3V on ESP/STM, you can take 500-1000 Ohms resistor.

Q: Why MOSFET are better than bipolar transistors?
A: MOSFETs are more effective in controlling powerful loads and heat smaller.

Q: Where can I buy electric components?
A: Internet-shops (AliExpress, ChipDip), local radio-shops.

Good luck in your electronics beginning =)

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