Wanna to build an inverter circuit..? This is an ordinary transistorised inverter circuit capable of driving medium loads of the order of 40 to 60 watts using battery of 12V, 15 Ah or higher capacity. This inverter will convert 12V DC input to become 230V AC in output.

Transistors T1 and T2 (BC548) form a 50Hz multivibrator. For obtaining correct frequency, the values of resistors R3 and R4 may have to be changed after testing. The complementary outputs from collectors of transistors T1 and T2 are given to PNP darlington driver stages formed by transistor pairs T3-T4 and T6-T7 (utilising transistors BD140 and 2N6107).

This in a really simple electronic buzzer circuit based on timer IC NE555. The IC 555 act as astable multivibrator which will generate audio signal frequency. The frequency value is depended the value of 56K resistor and 10nF (0.01 uf) capacitor… you may replace the 56K resistor with a variable resistor to adjust the frequency.

This is a police alarm circuit.  The two 555 timer ICs used as astable multivibrators. The frequency is controlled by the pin 5 of the IC. Actually, the sound is genereted by combination of sound from both IC 555. One timer generated low frequency and the another generated high frequency. By varying VR1 you can set how fast the siren changes from high freq. to low freq. VR2 sets the siren frequency.

This electronic schematic diagram is simple, you can use this schematic diagram as your simple electronic project. It’s easy and fun.

The main part of this doorbell circuit are two NE555 timer ICs. When  some one presses switch S1 momentarily ,the loud speaker sounds a bell tone as long as the time period of the monostable multivibrator built around IC1.

When the switch S1 pressed, IC1 is triggered at its pin 2 and output pin 3 goes high for a time period previously set by the values of POT R4 and POT R5.When the output ofIC1 goes high it resets IC2 and it starts to oscillate to make a bell sound through the speaker.The IC2 is configured as an astable multivibrator whose oscillation frequency can be varied with the help of POT R5.By adjusting the values of R4 & R5, modifications on the tone are possible.

You’re a newbie in electronics and you need to practice your electronics knowledge and then I suggest you to build this LED Flasher (Flip-Flop). This circuit is very simple and very easy to understand…

INTRODUCTION:

Flashing circuits are very interesting. They grab your attention and can be used in many applications. They consume very little energy and a single cell can last as long as 12 months. This is the simplest circuit capable of alternately flashing two LEDs.

SCHEMATIC DIAGRAM:

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