We understand that simple electronic circuits are very important. My friend said the large electronics project come of combining many small electronic circuits.

I also think that this passage is true. The some of your work may lack the small things. The small circuits will help it to work well.

Electronics are something near us. For example, cell phones, computers, televisions, etc.
Everything needs electricity as energy by plugging in a house or charging with AC adapter.

Inside these appliances consist of devices called those electronic components. They are connected in a manner known as the electronic circuit. Which using these appliances, we do not need to learn the workings of the electronic circuit inside it.

But learning electronic circuit is a very good skill or ability. The working principle of electronics may be tedious and useless.

Because of all the knowledge. It may be useless. If it is not used. We like the foods stored in the refrigerator. But it will not make full your stomach.

We have to bring it to cook or eat it.

If you have a passion for electronics works. We should learn electronics by using electronic circuits to create the fun projects. To solve everyday problems, is good, make your free time is useful.

Also, if you have technical skills. You can save money.  Because when the appliance is broken. You can repair first.

List of simple electronic Circuits

1A Fixed Regulator using 78xx

Usually, the main power supply of an electronic circuit is the battery. Because it is small, energy is clean and safe.

For example, most circuits use a 9V battery. When its power is gone. We need to buy a new replacement. It’s not convenient at all. Thus I make 9V power supply instead it.

The first choice we recommend using LM7809 from family IC-78xx as popular three-terminal linear regulators. In the circuit above.

The ACV 12V to 18V from a transformer is fed to D1-D4. To rectifier AC to DC.  Then, C1 filters to smooth DC.  Next,  the 7809 converts this unregulated DC voltage to stable +9V.

In addition, if you need other voltage levels. For example, 5V digital We use the IC-7805 instead of IC-7809. So IC-7812 = 12V DC output.

If you want to build this. You can see more simple electronic Circuits with PCB layout.

Variable power supply using LM317

Sometimes you need to use 1.5V power supply circuit. But you cannot use IC-7805. Or you need to use other voltage e.g. 13V or 4.5V.

The best way, you should use a variable Regulated power supply.  For beginner and easiest, we use LM317 (3 terminal positive adjustable regulators).

The LM317 is an adjustable regulator IC that designed to many supplies for 1.5A output and adjustable over 1.2V to 37V, and with current limiting, thermal shutdown, full protection.

This circuit is designed for you. It can supply voltage 1.2V to 30V at all range is about 1A.

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30 Minutes Transistor Timer

We use this simple electronic circuits. To learn the basic timer circuit. The working of the circuit is based on learning of the charge and discharge the capacitor.

And we can apply it to turn on-off electrical appliances. The application, just put relay instead of LED.

5-30 minutes timer circuit using IC 555

This timer circuit uses a 555 IC timer. This is small, compact and portable.

For the alarm by using the buzzer. We can select the time 5, 10, 15, and 30 minutes with S3 to S7 as the order.

It makes clear the brain is ready to continue to work.

Many friends like this. You may also like it. You can see more this 5-30 minutes timer with PCB layout.

Simplest Inverter circuit using transistors

When you need to use a small light bulb with a 12V battery.  But no light. Why? This light bulb requires high voltage,220VAC. How to convert 12VDC to 220VAC 50Hz?

You may have many ideas for this. But if you are in a hurry, here is another easy idea. It names the simplest inverter.

It just uses two power transistors, two resistors, and one transformer only. So easy! You may have them in store.

Parts list
Q1,Q2—MJ2955 PNP power transistor or equivalent.
R1,R2—68 ohms (or near value), 1-2W resistors.
T1—220V AC primary to 12V-0-12V, 500mA secondary transformer.

This circuit does not need to use the PCB. You can solder them directly leg to leg and wires.

Remember! The load should be light bulbs or lamps, max 10W.

Small high volts shock using 2SC1815 transistor

If you want to make a funny circuit for people. This circuit may make a laughter.  It is a small high volts shock circuit. The output is a low current. It is not harmful to people.

In circuit has a few components just two small NPN transistors, 2 resistors, and a transformer. So easy to builds and inexpensive!

Low watts Audio amplifier circuit with PCB

This is my first audio amplifier circuit. I use LM386 is main, it is a low voltage (5V-12V) amplifier designed specifically for audio applications. Which can be used with a small 9 volts Battery operated, Current use as little as 5 milliamps. And amplification up to 500 mW. The gain is internally set to 20. The gain can be increased to 200 by connecting a 10-uF capacitor across pins 1(+) and 8(-). Enough to expand the sound from a mobile phone to 3-inch loudspeaker easily.

Low watts Stereo amplifier circuit

This is my first stereo power amplifier circuit kits that can be used with a small 9 volt Battery Operated, Current use as little as 5 milliamps.And amplification up to 500 mW.

LED Chaser circuits using IC 4017 + IC 555

There are 5 circuits with PCBs about LED Chaser circuits or Running lights. They use IC-4017 to drive LEDs and IC-555 as oscillator pulse generator. It is best for a beginner or for kids to learn digital also my son loves them.

Dual LED Flasher using 2N2907

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

Simple music sound using UM66T

In the circuit basically usability base IC UM66T use the sound of music sweet-sounding origin and be usable easily. It uses just integrated one circuit and a loudspeaker, piezo buzzer, the small-sized, and have power supply 3V only.

Learn more : Simple Electronic circuits