electronics-amplifier tutorial

This audio amplifier circuit, connected to 32 Ohm impedance mini-earphones, can detect very remote sounds. Useful for theatre, cinema and lecture goers: every word will be clearly heard. You can also listen to your television set at a very low volume, avoiding to bother relatives and neighbors. Even if you have a faultless hearing, you may discover unexpected sounds using this device: a remote bird twittering will seem very close to you.

Skema Rangkaian 1,5V Earphones Audio Amplifier

The heart of the circuit is a constant-volume control amplifier. All the signals picked-up by the microphone are amplified at a constant level of about 1 Volt peak to peak. In this manner very low amplitude audio signals are highly amplified and high amplitude ones are limited. This operation is accomplished by Q3, modifying the bias of Q1 (hence its AC gain) by means of R2.

A noteworthy feature of this circuit is 1,5V battery operation.
Typical current drawing: 7,5mA.

This audio amplifier circuit works up to 2 x 22Watt with main power IC TDA1554. The circuit has only very few components and works best with a 4 Ohm speaker.

IC TDA1554 must be connected to a heat sink. A computer cabinet fan can also be used in addition. Any way better the cooling better the performance.The circuit roughly draws 6A current at 12 V at full volume.So the power supply must be any thing more than 6A.Up to 18 V can be used

Skema rangkaian TDA1554 audio amplifier
2 x 22W BTL

This is circuit of 15W BTL stereo channel audio power amplifier based IC TA 8215 developed by Toshiba. In this power amplifier circuit, two TA 8215 ICs are used. This is for obtaining four channels that is two channels from each IC. TA 8215 is an IC with power amplifier stages and preamplifier integrated inside it.

The power supply required for this amplifier is single 12 V DC supply. The maximum output power delivered from each channel of this amplifier is 15 W to a 4 ohm speaker and hence the name 4×15 W power amplifier.

Skema rangkaian Car Audio Amplifier
15W BTL Stereo

TA8215 IC

R1 with R2 forms a voltage divider that attenuates the input signal by 24dB. Considering the chip's 50dB gain, that still leaves 26dB overall gain, slightly more than enough to fully saturate the amplifier when the sound card works at maximal output. C1 blocks DC at the preamplifier input. C2 is the ground return of the feedback circuit. These two capacitors need to be in the ratio shown, in order to suppress switching clicks when powering the circuit on and off. The output pins 15 and 16 are connected directly to the speaker, while C7, R6, C8 and R7 provide the proper load phase shifting to avoid high frequency instability.

The power supply is decoupled with a rather small 100uF capacitor. That's enough for higher frequency decoupling, and at lower frequencies anyway the large capacitors in the PC power supply are fine. Pins 10 and 17 supply the power amplifiers, while pin 9 provides power to the pre stages. This power is filtered by C3. The power control pin 4 allows to shut down the amplifier, an option not used here, so it's tied to 12V. Pin 1 is a muting input, also not used, and left open.

The Nokia X3-02 Touch and Type is the first phone from Nokia to feature both a touch screen and the more traditional keypad. This best-of-both-worlds approach allows users to have all the fun of the touch screen experience, while keeping the undeniable practical benefits and ease of use that a keypad provides.

In terms of outward appearance, the Nokia X3 isn’t really breaking any new ground, but the 2.4” touch screen and super-slim design give the phone a modern, sleek look. Add to this the brushed aluminium cover, available in a range of 5 colours, and Nokia have a phone that would look good in anyone’s pocket.

Despite two sets of controls, though, the X3 Touch and Type is one of Nokia’s thinnest devices: it’s 9.6mm deep, 106mm tall, 48mm wide and weighs just 78g. The brushed aluminium finish and choice of five colours are also likely to appeal to fashion-conscious mobilists.

Even though it has a svelte profile, the X3 Touch and Type is full of features. It comes with four bands for voice, 3G, HSPA and WiFi for data, a music player and an FM radio. Mobile photographers get a 5-megapixel camera, with 4X digital zoom, which takes both still images and videos. The Communities app will keep you up-to-date with Twitter and Facebook.

The X3 Touch and Type has also got dedicated music and messaging keys for quick access to the music player and email. All the regular webmail and chat services are catered for by the included applications. Apps downloaded from the Ovi Store can be used through the 2.4-inch touch screen, so users don’t miss out on any of the latest games or productivity apps. They can also use the keys, of course, if they prefer, or adopt a hybrid approach.

PRICE: €125 (about £100)

SPECIFICATIONS
General
2G Network GSM 850 / 900 / 1800 / 1900
3G Network HSDPA 850 / 900 / 1900 / 2100
Announced 2010, August
Status Coming soon. Exp. release 2010, Q3

Size
Dimensions 106.2 x 48.4 x 9.6 mm, 45.2 cc
Weight 78 g

Display
Type TFT resistive touchscreen, 256K colors
Size 240 x 320 pixels, 2.4 inches

Sound
Alert types Vibration, MP3 ringtones
Speakerphone Yes
- 3.5 mm audio jack
- Dedicated music key

Memory
Phonebook Yes, Photocall
Call records Yes
Card slot microSD, up to 16GB

Data
GPRS Class 10 (4+1/3+2 slots), 32 - 48 kbps
EDGE Class 10, 236.8 kbps
3G HSDPA, HSUPA
WLAN Wi-Fi 802.11 b/g/n
Bluetooth Yes, v2.1 with A2DP
Infrared port No
USB Yes, v2.0 microUSB

Camera
Primary 5 MP, 2592 x 1944 pixels
Video Yes
Secondary No

Features
Messaging SMS, MMS, Email, IM
Browser WAP 2.0/xHTML, HTML
Radio Stereo FM radio with RDS
Games Yes + downloadable
Colors White Silver, Dark Metal, Petrol Blue, Pink, Lilac
GPS No
Java Yes, MIDP 2.1
- Windows Live Messenger, Yahoo Messenger, Gtalk
- Facebook, Twitter
- MP4/H.263 player
- MP3/WAV/eAAC+ player
- Organizer
- Voice memo
- T9

Battery
Standard battery, Li-Ion (BL-4S)
Stand-by Up to 408 h (2G) / Up to 408 h (3G)
Talk time Up to 5 h 20 min (2G) / Up to 3 h 30 min (3G)

What's so special? Well, first of all - a very low harmonic distortion. Usually, manufacturers indicate the maximum power of its regular ingenious handicrafts with the harmonic content of 10%. At the same chip, CT at the maximum specified power is only 0,5%! Thus, it is the most honest of all mikruha I encountered.

In the chip implements two identical amplifier channels and features are given for the stereo mode of the amplifier. Circuit can also operate in mono - in bridge inclusion. In this case, the output power at CT = 0.5% of 120 watts. Other features remain virtually unchanged.

Skema rangakain amplifier 60W stereo LM4780

Skema rangakain amplifier 120W Bridged LM4780

LM4780 IC pin

Skema rangkaian TDA 1910 audio amplifier

TDA 1910 IC Pin

The TDA 1910 IC is a monolithic integrated circuit inmultiwatt package, intended for use in Hi-Fi audio power applications, as high quality TV sets. The TDA 1910 meets the DIN 45500 (d = 0.5%) guaranteed output power of 10W when used at 24V/4W. At 24V/8W the output power is 7W min.

Skema rangkaian 20 watt audio amplifier TDA7240

TDA7240 IC Pin

This circuit of audio amplifier based IC TDA7240 can deliver 20 watts of audio output power into a 4ohm load. The IC has minimum external parts count and is available in the 7 pin compact Heptawatt package. The IC also has a lot of good features like loud speaker protection, short circuit protection, low noise, low distortion etc. The circuit can be operated from a 12V DC single power supply and this makes it very useful in car audio application