schematic knowledge

We all know that brand names matter when purchasing car audio hardware. There are brands that are surely more reputable than others. When you are at the store and they offer choice after choice after choice, suddenly you feel overwhelmed on what really to buy. But you can be assured of one thing, if they offer you an Alpine car stereo you can’t go wrong with it.

Alpine car stereo and electronics, founded in 1978, is a world leader in the industry of high performance mobile electronics. They specialize in mobile multimedia, an integrated system approach incorporating digital entertainment, security and navigation products for the mobile entertainment.

Alpine car stereos are a new breed of units which feature the convergence of high performance audio, video, navigation and telematics in the form of Mobile Multimedia. Navigation systems act as the resource center of the Alpine car stereo Mobile Multimedia lineup. Intelligent Transportation Systems (ITS), DVD players, Dolby Digital systems, satellite digital audio radio, mobile data linking and communication through telematics devices will be fused with navigation systems to create a platform of products. Mobile Multimedia integrates Alpines innovative audio, video, security and navigation products, as well as its new GUI for Drivers, human interface and information communications technology.

To grasp what the Alpine car stereo Mobile Multimedia is, take a look at the IVA-D901 Alpine car stereo Mobile Multimedia Station/CD/DVD Receiver/Ai-NET Controller.

The IVA-D901 has 400% more pixels than a conventional in-vehicle display, meaning that it has 1.15 million pixel elements. It has 50W x 4 built-in power and 3 PreOuts (4 volt), SAT Radio ready, a Hard Disc Drive (HDD), and Alpine car stereo Navigation. Key features include:

- 7" Fully Motorized Wide Screen Monitor

- 18W x 4 MOSFET Amplifier

- Built-in Dolby Digital/DTS Decoder

- Bass Engine® Plus

- Subwoofer Level Control

- Bass Center Frequency Control

- Bass Band Width Adjustment

- Treble Center Frequency Control

- Subwoofer Phase Selector

- Bass Type Control

- 4-Ch Digital Time Correction

- 3 Position 12 dB/Oct Crossover

- MediaXpander™

- SAT Radio Ready

- MP3 Text Information Display

- Quick Search Function

- CD/CD-R Playback

- CD Text, Text Display, Text Scroll

- M DAC

- MaxTune SQ Tuner

- 3 Auxilliary A/V Inputs with Remote Control Input

- Dedicated Navigation Input

- Dedicated Camera Input

- 2 Auxilliary Monitor A/V Outputs

- Navigation Audio Mix

- 3 PreOuts (4 volt)

- MM Driver (Hard Disc Drive) Ready

- MobileHub Ready

- Ai-NET Control Center DVD/CD/MP3 Changer Controller

- "Digital Art" Spectrum Analyzer Display

- RUE-4190 Universal Wireless Remote Control Included

If these all seems too much for you, Alpine car stereos also have more conventional head units to offer. The CDA-9835 Alpine car stereo In-Dash CD Player/Ai-Changer Controller lets you fully customize both illumination and sound, with a range of 512 colors and super-versatile Bass Engine functions like digital time correction and parametric EQ. You can download audio parameter settings and connect and control as many as eight amps. The BioLite display, Menu key and rotary knob make operation extremely easy.

Like most Alpine car stereo units, it is also SAT Radio Ready, giving you a much greater choice of listening options than ordinary local AM/FM radio. You can select from among a wide range of music genres, news, sports, and talk programs with digital quality anywhere.

 

This is a very simple design circuit that can be used to check the hfe of transistors. Both PNP and NPN transistors can be checked using this circuit. Hfe as high as 1000 can be measured by using this circuit. The circuit is based on two constant current sources build around transistors Q1 and Q2. This is the figure of the circuit.


Operation of the circuit is the Q1 is a PNP transistor and the constant current flows in the emitter lead. The value of constant current can be given by the equation; (V D1 -0.6)/ (R2+R4).The POT R4 can be adjusted to get a constant current of 10uA.

The Q2 is an NPN transistor and the constant current flows into the collector lead. The value of this constant current can be given by the equation; (VD2-0.6)/(R3+R5).The POT R5 can be adjusted to get a constant current of 10uA.This constant current provided by the Q1 circuit if the transistor under test is an NPN transistor and by Q2 circuit if the transistor under test is a PNP transistor is fed to the base of transistor under test. This current multiplied by the hfe flows in the collector of the transistor and it will be indicated by the meter. The meter can be directly calibrated to read the hfe of the transistor. The Zener diodes must be rated at least 400mW. J1 and J2 are transistor sockets.