This application is a great reference for electronic engineers. It will be useful for both beginners and experienced electronics enthusiasts.
This application contains more than 110 guides and calculators for various areas of electronics. The program is designed for light and dark themes and translated into eight languages: English, French, Spanish, German, Italian, Portuguese, Russian, Ukrainian.
The app contains calculators and guides:

Basic
- Omn law
- Power, voltage and current
- Resistive voltage divider
- Wheatstone Bridge
- RC circuit time constant
- Battery Life

Resistors
- Resistor color codes
- Resistor color codes
- SMD resistor codes
- SMD resistor codes
- EIA-96 Encoding
- Standard values finder for resistor
- Series resistors
- Parallel resistors
- E series

Capacitors
- Ceramic disc capacitors codes
- Film capacitors codes
- Capacitor working voltage codes
- Film capacitors color codes
- SMD Tantalum electrolytic capacitors codes
- Series capacitors
- Parallel capacitors

Inductors
- Inductor color codes
- Inductor color codes
- SMD inductors codes
- SMD inductors codes
- Series inductors
- Parallel inductors

Diodes
- Diodes introduction
- Rectifier diodes
- Signal diodes
- Varicap
- Zener diode

Transistors
- Bipolar transistors
- Metal-Oxide-Semiconductor Field-Effect Transistor
- Junction Field-Effect Transistor
- Darlington transistor pair

Thyristors
- Thyristors
- Gate Turn-Off Thyristor
- TRIAC
- DIAC

PowerSupplies
- AC parameters and rectified value
- Half-wave rectifier
- Full-wave rectifier
- Bridge rectifier
- Capacitive power supply
- Voltage multiplier

Voltage and current regulators
- LM317 Voltage regulator calculator
- Bipolar voltage regulator for LM317 and LM337
- LM317 Current Source calculator
- Zener reference voltage source

LED
- LED Single Resistor calculator
- LED Series Resistor calculator
- LED Parallel Resistor calculator
- 7-segment LED display
- Decoder (driver) for 7-segment displays CD4511

Photocells
- Photodiode
- Photoresistor
- Phototransistor
- Optocoupler

OP
- Non-Inverting OP Amplifer Gain calculator
- Inverting OP Amplifier Gain calculator
- OP Voltage integrator
- OP Voltage Differentiator
- OP Voltage comparator

Frequency
- Capacitor reactance
- Reactance of an inductance coil
- Gain conversion to decibels
- dBm to Watts conversion
- T-Attenuator
- Pi-Attenuator
- L-Attenuator
- Bridged T-Attenuator

Filters
- RC Low Pass Filter
- RC High Pass Filter
- RC Band pass filter
- RL low-pass filter
- RL high-pass filter

Multivibrators
- Astable multivibrator
- Monostable (waiting) multivibrator
- Bistable multivibrator
555 Timers
- Astable mode
- Monostable mode
- Bistable mode
- Schmitt trigger
- Connecting LEDs
- Light detector
- Relay control
Logic
- AND logic gate
- OR logic gate
- NOT logic gate
- NAND logic gate
- NOR logic gate
- XOR logic gate
- XNOR logic gate

This application's contents and languages are updated in new versions.

// Option A //

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You need enable the option "Unknown Sources".
1. Click on the above link to download Electronic circuits calculator mod APK.
2. Save the file in your device Downloads folder.
3. Now tap on Install and wait for the installation to finish.
4. Once it is done, open the game and start playing it right away.

// Option B //

To download Electronic circuits calculator from HappyMod APP, you can follow this:
1. Open your browser and download the HappyMod APK file from HappyMod.com - the only official website of HappyMod.
2. Open Android Settings and go into Privacy or Security.
3. Tap the option to Allow Unknown Sources and enable it.
4. Go to your Android downloads and tap the APK file.
5. Follow the directions on the screen to install it.
6. Search Electronic circuits calculator in HappyMod App.