99+ Simple electronic circuit for beginners

Two LED flasher circuits

This calls for more Free Running Multivibrator work to resemble Flip Flop, which encourages itself repeatedly. The Q1 and Q2 be Transistor PNP be usable general (2N3906,2N2907, etc.)

Learn more: LED blinking circuit using transistor

Flashing Bicycle LED Taillight Circuit

Using transistors instead of ICs because they are simple and economical. It is quite simple because there are few components. But learning its working principles is very interesting.

Read more: DIY bike light

LM386 Audio Amplifier Circuit

This is my first audio amplifier circuit. I use the LM386 as the main amplifier; it is a low-voltage (4V–12V) amplifier designed specifically for audio applications. Which can be used with a small 9V or 3.7V Li-ion battery operated with as little current as 5 mA and amplification up to 500 mW. It is enough to expand the sound from a mobile phone to a 3-inch loudspeaker easily.

Non-Contact Voltage Tester circuit

Do you want a tool to check the AC main without touching it?  This circuit can do it. In a simple way, in-circuit use transistors without IC. You can hear a sound, and show it with an LED display.

Automatic Solar Light circuit

Let’s create a simple automatic solar light circuit or a Solar Night Light Circuit. My kids made it for daily use and to learn electronic circuits. They worked well, so we are happy.

Simple Condenser Mic Preamplifier Circuit

The mic brings to change the sound into electrical signals. it is a basic circuit and uses a 9V battery

5-20 Minutes Timer using 555 timer

This timer circuit uses a 555 IC timer. It is small, compact, and portable. For the alarm by using the buzzer.  We can select the time 5, 10, 15, and 20 minutes with S3 to S7 as the order. You can read more: 5-20 minutes 555 timer with PCB layout.

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Gel cell battery charger circuit

It can charge any size of the Gel cell battery and extend the life of the Gel Cell battery. While the circuit is running, the LED indicates charging

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Simple AC inverter circuit

When you need to use a small light bulb with a 12V battery. But no light. Why? It requires an AC line of 220 volts. How do I convert 12 VDC to 220 VAC? There are many ideas for this. But we are in a hurry. Try this circuit, the simplest inverter, with just basic components, 2 power transistors, 2 resistors, and one transformer. So easy!

Automatic LED Night Light circuits

Try making a simple automatic LED flashlight with only 5 basic components. And, we would have learned about the transistor, LDR, LED, and more that work together as a voltage divider.

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TDA2822 stereo amplifier circuit

Try making a simple automatic LED flashlight with only 5 basic components. And, we would have learned about the transistor, LDR, LED, and more that work together as a voltage divider.

Simple Water Level Alarm Circuit using a Transistor

It worked by sounding an alarm when the water level rose to the set level. So we can close the water valve in time and prevent an overflow with only basic electronic components.

Solar-powered Plant watering alarm circuit

It will sound an alarm whenever the soil is dry. So, we can water the plant to prevent it from dying. The solar cell works like a 6V DC power supply to save us money by not requiring batteries. It can be built easily with a few parts (without IC).

30 min Transistor Timer Circuit

We can use these simple electronic circuits. To learn the basic timer circuit. The working of the circuit is based on learning the charge and discharge of the capacitor. And we can apply it to turn on-off electrical appliances. In the application, just put a relay instead of an LED. 

Simple Motion Sensor Alarm

If you have your own private space and do not want someone to intrude, this motion detector alarm circuit will definitely reduce your worries.

Continuity Tester Circuit with Buzzer and LED

This is a continuity tester circuit with a buzzer and LED. Also, I like this circuit. Because unnecessary to take my eyes off the tested circuit. We will hear the buzzer and see the LED glow. READ MORE

Simple 1.2V AA Ni-MH Battery Solar Charger circuits

Create it with common parts for charging 1.2V AA, So easy and cheaper. READ MORE

Constant current circuit using transistors

Learning experiments with a simple constant current circuits using transistors, and a few plain parts, was so helpful, especially the Ni-HM battery charger.

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1.5V LED flasher circuits

It’s efficient enough to last for 1 year. These circuits only use a few components consisting of two to three transistors, four resistors, and three capacitors.

LM317 Power supply

Sometimes you need a 1.5V power supply instead of a battery. Or other levels like 13V, 4.5V, 7.5V, etc. Use this variable-regulated power supply. Which is my first power supply. It has still worked well after 30 years.

3.7V to 5V Boost DC converter

Here is a 3.7V to 5V boost converter or step-up switching circuit using MC34063 and a few parts,1N5819,100uH. For 200mA-300mA of load current.

9V Regulator circuit using 7809

Let’s create a 9V regulated power supply circuit to replace a 9-volt battery. These circuits can deliver 10 times more current than a battery and saving us time and money to replace it when it dies.

Simple 12V DC Power Supply

If you are looking for a 12V AC adapter. You can create it yourself even as a newbie. It can supply all circuits that require a 12V DC source under 2A. For example, the TDA2004 Audio Amplifier. Especially, it is built with a hammer!

Toy Organ circuit using transistors

Let’s play with a simple toy organ circuit. A daughter of mine is interested in piano. But at the moment we are not ready to study it. Believe it or not, we can create a simple piano circuit by ourselves.

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Making Simple Buzzer circuit

Let’s make the electronic buzzer circuit in simple ways. But useful and well worth it and the price is lower than 1$. By using just a 9-volt battery only.

Police siren circuits

It is easy to do that. They have 3 circuit ideas for you.

Signal injector circuits

 It can be a tool or accessory for repairing television or radio receivers, amplifiers, etc. It will produce a small-frequency signal. It uses a 1.5V battery power supply.

Triangle wave generator circuit using Schmitt-Trigger

It can create a Square or Triangle wave at the output with just a small number of electronic components. I made this a while back to learn about CMOS Gates and an Astable Multivibrator.

60 Hz Clock Generator Circuit using MM5369

It uses MM5369 and crystal as the main components. So, they can be used as a calibrator for standard frequency. They also give 1HZ, 1/60Hz, and 3.579MHz at TP.

ICL8038 Function Generator circuits

If we need a function generator circuit. We have many ways to do it. Using the ICL8038 waveform generator is a great option. It is easy to use and inexpensive.

FM wireless microphone circuit diagram

AM radio receiver circuit diagram

Simple Automatic Motion Sensor Light Circuit

Is there a way we could save as much electricity as possible?

LED Chaser circuits using 4017 + 555

There are 5 circuits with PCBs for LED Chaser circuits or Running lights. They use CD4017 to drive LEDs and IC-555 as an oscillator pulse generator. It is best for a beginner or for kids to learn digital also my son loves them.

LED chaser circuit using transistors

Since my daughter has tried making the LED chaser using ICs (CD4017 and NE555), it has worked well. But recently, she has been learning how to use transistors.

Simple Coin Toss Game circuits diagram

It is a type of simple electronic game that simulates a real coin toss with LEDs. You could build it in your free time to play and enjoy with others.

Outdoor 12V solar light circuits

If we need lighting around our home at night. But those areas are without an AC line because it is hard to do the wiring there. And we also want to save on electricity costs.

Automatic Plant Watering with a Solar Cell

Using a solar cell, a DC pump, a 555 timer, and an LM311 comparator. It worked well and was also very efficient, requiring only power from the solar cell rather than a battery. 

OFF Delay timer circuit

The easiest way is to turn on the light only when needed and turn it off when not. But in practice, we often forget to turn off the lights even when they are not needed.

Simple Speaker Turn-on Delay Circuit

Every time you turn the OCL power amplifier on, within the first 3 S, you hear a loud “tlub” sound. It is annoying. Also, caused by a voltage spike that can damage the speaker. But this circuit can help us.

10 Key Code Lock Switch Circuit

We do not need to carry a load key and do not worry about your keys being lost. We just must remember to commit to code only.

Digital Electronics Projects using Flip Flops

I am going to show you these Flip-Flop Switch Circuits. Imagine you can use your life is better with your own electronic project.

Battery Voltage Monitor circuits

When the voltage level is lower below 12.4V. To extend the lifespan of the battery, we should always bring it to be fully charged. The circuit will alert us.

The Op-amp IC tester circuit

You can use them to fast-check the many op-amps IC good with blinking LED circuits. It has a few parts so cheap and easy to build.

7805 Constant Current Battery Charger circuit

7805 has many helpful. One thing is we can use them as constant current regulation. It is so easy and more convenient than using transistor circuits.

3.7V Li-ion Battery Charger Circuit

We made the circuit with commonly used components such as the NE555 timer and TL431 shunt regulator. It uses the principle of charging the battery with a low-current pulse signal. Making it a safe and impressionable performance charger.

LM317 Ni-MH charger circuit

Here is a constant current and voltage AA Ni-MH battery charger circuit. 

6V, 12V, 24V Lead acid battery charger using LM317

This lead-acid battery charger project is for 6V, 12V, and 24V batteries. Although there are many methods to choose from. But you may be missing If not read this post to the end.

5V Low Dropout Regulator Circuit using transistor

The 6V input voltage can make the output regulator 5V 0.5A. So, the voltage across it is 1V only.

Read more: 5V transistor Low Dropout Regulator Circuit

1.5V or 3V Step-up Switching regulator circuit

5V 0.5A Simple Switching Regulator circuit

Basic Amplifiers

• 4 transistor audio amplifier
• 3 transistors Audio Amplifier
• Simple transistor intercom
• Simple speaker delay