Christmas Decoration Project

This project flashes 18 LEDs at three different rates and you can use these to create a Christmas decoration of your choice. The circuit is kept simple (and cheap!) by using the 4060B IC which is a counter and oscillator (clock) in one package. The circuit requires a 9V supply, such as a PP3 battery. It will not work with lower voltages and a higher voltage will destroy the LEDs.

The preset variable resistor can be used to adjust the oscillator frequency and this determines the flash rate of the LEDs. The IC limits the current to and from its outputs so the LEDs can be safely connected without resistors in series to limit the current. The stripboard part of the circuit is easy to build but the wiring for the LEDs needs care so detailed instructions are provided below.

Download this schematic diagram.

Parts Required

• resistors: 10k, 470k
• preset: 47k (this could be 100k if necessary)
• capacitor: 0.1µF
• 4060B IC
• 16-pin DIL socket for IC
• LEDs × 18, 5mm diameter, any mix of colours: red, orange, amber, yellow or green
• on/off switch
• battery clip for 9V PP3
• stripboard 13 rows × 18 holes

Download list datasheet semiconductor parts. (PDF Format)

1. CD4060B

Electronic Timer Switch.

This electronic timer switch project is a good project to build to simulate the presence of occupants in a house. In these days when security is becoming more of a concern when no one is at home, having this device will deter the thief from breaking in. When power up, after 60 minutes, the relay will turn ON for 100 secs, OFF for the next 100 secs, and ON again for 100 secs before OFF again for the next 60 mins. This sequence will be repeated. A device such as a lamp that is connected to the relay will turn ON and OFF according to this timing.

Schematic Diagram

The schematic of the project is as shown below.

Download this schematic diagram.




Parts List

Download datasheet semiconductor component. (PDF Format)

1. CD4060B
2. IN4148
3. IN4003
4. 2SC2002

800W Audio Amplifier with MOSFET

Here the schematic diagram of 800 watt audio amplifier with MOSFET.

This amplifier can be used for practically any application that requires high power, low noise, distortion and excellent sound. Examples would be Sub-woofer amp, FOH stage amplifier, One channel of a very high-powered surround sound amplifier etc.

For detail explanation about how this circuit works include the large schematic diagram, power supply schematic diagram and complete component listing, download this complete article

http://circuitdiagram.net

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.

Download this schematic diagram.

Download datasheet semiconductor component. (PDF Format)

1. TDA2052

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

35W RMS x 3-Channel Power Amplifier System.

Design Objectives This design is intended to drive the rear (stereo) and center channel speakers for surround-sound applications. This project combined with the 60W+60W power amplifier, which will drive the main stereo (front) speakers, gives a full 5 channel surround sound systems (Total power = 225W RMS). The power supply circuitry, PCB size and dimension should be designed to match nicely with the 60W+60W power amplifier so that later they may be nicely cased togather.

System Operation & Description The LM4781 3-channel audio power amplifier are configured as non-inverting amplifier which has a gain of 20V/V per channel, which is high enough to maintain stability and not too high until increasing the noise and THD+N performance. The inputs are taken from the RCA jacks which then feed to three high quality 1uF metallized polyester capacifor with 63V rating. The outputs are wired to the speaker terminals directly.

The schematic diagram is taken straight out from the National Semiconductor's referance PCB design schematic. However I have omitted the muting switch and replaced it with the soft start circuit, as explaned in the LM4781 datasheet. I have also added the L//R network (L=0.7uH, R=10 ohms 2W) at all the outputs.

For detail all discription, click here.