500W Inverter 12V DC to 220V AC

This is inexpensive inverter circuit which able to convert 12V DC become 220V AC. IC CD4047 is use to generate the square wave of 50hz and amplify the current and then amplify the voltage by using the step transformer.

How to calculate transformer rating

The basic formula is P=VI and between input output of the transformer we have Power input = Power output

For example if we want a 220W output at 220V then we need 1A at the output. Then at the input we must have at least 18.3V at 12V because: 12V*18.3 = 220v*1

So you have to wind the step up transformer 12v to 220v but input winding must be capable to bear 20A.

60 Watt Amplifier using TDA2052

This is HiFi audio amplifier system. This amplifier is AB class amplifier and has very low distortion that's why this amplifier can be used for HiFi audio system. TDA2052 has mute and st-by functions so it can be controlled by external digital circuits. Very high temperature and output short circuit protections are included. You should use a heatsink to dissipate the excess heat.

Functions of the Components:

1. R1 - Input Impedance
2. R2,R3 - Gain (32dB)
3. R4 - Input Impedance in Mute Mode
4. R5 - Standby Transition Time
5. R8 - Output Frequency Balancing
6. R9,R10 - Discharge Resistors
7. C1 - Input Coupling Capacitor
8. C3 - Feedback Coupling Capacitor
9. C4 - Standby Transition Time
10. C5 - Output Frequency Balancing
11. C6,C7 - Supply Stabilizing Capacitors
12. C9,C10 - Supply Filter Capacitors

Component List:

Component	Value	Number
R1,R2,R4,R5	11k ¼ W	4
R3	560, ¼ W	1
R6	7.5 K, ¼ W	1
R7	1 K, ¼ W	1
R8	4.7 , ¼ W	1
R9,R10	1.2 K, ¼ W	2
C1	2 uF/25 V	1
C3,C4	10 uF/25 V	2
C5,C9,C10	100 nF	3
C6,C7	1000 uF/40 V	1
U1	TDA2052	1

1.5 Watt FM Transmitter

This is the the schematic diagram of 15 watt FM transmiter. The range should be 1-2Km with normal FM receiver.

Components List:

R1	220K
R2	4.7K
R3,R4	10K
R5	100ohm
C1,C2	4.7uF electrolytic
C3,C4	1nF
C5	2-15pF
C6	3.3pF
Q1	BC547C
Q2	2N2219A
P1	25K
MIC	ecm series

60W Power Audio Amplifier with 2N3055

This circuit is simple and inexpensive:

This is a class B amplifier, this means, that a current must flow through the end transistors, even if there is no signal on the input. This current can be regulated with the 500Ω trimmer resistor. As this current incrases, the sound of the amplifier gets better, but the end transistors are more heating. But if this current decrases, the transistors are not heating so much, but the sound gets worse.

you can download the document version here

Infrared Modulation Identifier

This is the schematic of Infrared Modulation Identifier Via Remote Control.

The circuit illustrates how the modulated carrier of infrared is measured by displaying the waveform on a frequency counter after the signal received is amplified.

More explanation, visit this page.

10 Band Graphic Equalizer

This is 10 band graphic equalizer for one channel (mono) audio system. You need build 2 similiar circuits for 2 channel (stereo) audio system.

This equalizer build based on TL074 low noise JFET op-amp which will give you high quality audio output.

Part List

R1....20= 10Kohms C4= 10nF polyester C18= 68pF polysterine R21....40= 1Mohms C5= 47nF polyester C19= 360pF polysterine R41= 10Kohms C6= 4.7nF polyester C20= 36pF polysterine R42= 1Kohms C7= 22nF polyester C21= 4.7uF polyester R43.....52= 2.2Kohms C8= 2.2nF polyester C22-23= 33pF polysterine R53.....62= 47Kohms C9= 12nF polyester C24= 10uF 25V R63-64-66-67= 47Kohms C10= 1.2nF polyester C25-26= 47uF 25V R65= 10Kohms C11= 5.6nF polyester C27...32= 47nF polyester R68-69= 47 ohms 1/2W C12= 560pF polysterine IC1...3= TL074 RV1....10= 100Kohms lin FADER C13= 2.7nF polyester S1= 2X4 SW for stereo RV11= 10Kohms log. C14= 270pF polysterine C1= 180nF polyester C15= 1.5nF polyester C2= 18nF polyester C16= 150pF polysterine C3= 100nF polyester C17= 680pF polysterine

Multi Channel Audio Mixer using JFET 2N3819

This is multi channel audio mixer using main component JFET 2N3819. You can add the input as many as you need for your project.

2N3819 is an n-channel JFET especially manufactured for RF and mixer applications and provides very low noise, very low distortion and excellent high frequency gain.

6 Channels Audio Mixer

This is 6 Channel Audio Mixer circuit. 3 channel for microphone input and the others 3 channel for audio input like CD player, computer, or television. There will be 6 potensiometer to control the volume of each channel.