1diy issue18 dr100w pa

Heart Systems V1.0

PRELIMINARYdigital power amplifier module

LearningElectronics Project

Easy,

Fast & Fun...DDDDDiiiiiYYYYY Affordable

and EAF2

Heart Systems

The DR100W conCEPT

Welcome to DR100W conCEPT - thePower Amplifier Module. Issue No. sev-enteen is a continuation of isse 15 and16, dealing with the power amplifier - Ishould say, the “digital” power amplifiermodule.

Before that, in case you have not heardabout DR100W conCEPT --- what is it,you may ask.......... well, DR100WconCEPT is conceived basically forLearning analog and digital audio, poweramplifier hardware design, systems ar-chitecture and design and MCU firmwareprogramming.

Nahhh!!! Not those power amplifier youhave seen, the DR100W conCEPT is adiy (do-it-yourself) and fully bundled with:

Figure 1 : The DR100W digital Power amplifier of DR100W conCEPT

- designed for personal taste of stereo audio system- diy Assembly of equalizer, tone control, power amplifier & protection Modules- learning mcu programming- control via I2C protocol / TTL- systems integration & testing- product development

http://www.1diycentre.comNo.18DIY Issue No. Eighteen

Improvement

Power Amplifier Module

LCD display:you can display your name, your girlfriendname or the name of special someone onthe 20x4 LCD, its nice to see someonename “there - on the LCD”.

preset Equalizer/Tone Control:which adds quality to your listening plea-sure with the Turbo Bass - sometimes it iscalled Bass Boost, blended with +/- 14 dBof Bass and Treble. It has a 3D sound alsothat makes the stereophonic emphasis evenwith a close speaker distance. The effectin some “real stereo music” makes the soundrevolving as perceived by our ear.

digital Class D :it is blended with high efficiency digitalPower Amplifier with all the protectionneeded for your Speakers.

conCEPTDR100WEqualizer, Tone Control, PowerAmplifier, MCU Programming

In this issue diy issue 18, we will dis-cuss the Power Amplifier Module - wesimply called it - - - - DR100W_PA.

Preliminary

DR100W

Control ModuleEQ

Music SourcePower Source

Heart Systems V1.0



DR100W conCEPT Building Block

In DIY Issue 15, it discussed the DR100WconCEPT block diagram. Please check the DIYLearning & Improvement issue 15.

In this issue, DIY Learning & Improvement issue18, we will discussed mainly the digital power am-plifier along with the Protection Module, see theshaded block in green of Figure 3 and Figure 4.

To connect the idea of the DR100W conCEPT, youneed to read also DIY Learning & Improvement is-sue 16 which discussed the Equalizer and digitaltone control - the module that will drive the DR100Wpower amplifier, that module is called DR100W_EQ.

ipod

Mobile

MP3/MP4

STB

DR100w_EQ

Equalizer & ToneControl

digital Bass & Treble Left Speaker

RightSpeaker

Music Source Tonal Block Power Amplifier Speakers

Figure 3 : THE DR10W conCEPT simplified Diagram

digital EqualizerRock, Pop, Classic, Jazz &flat

digital Gain

digital Turbo Bassdigital 3D Sound

DR100W_PAClass DPower

Amplifier

Left

Right

DR100W_PMProtection

Module&

Power ControlLeft

Right

ProtectionModule

Woofer

Tweeter

Mid-Range

Control ModuleLCD, keyboard, Home Automation

Remote Control

What’s that calledClass “D”

In learing political science, there is this coursecalled “AB political science”. In Amplfier, there isalso called Class AB - simply, the combination ofclass A and B - a compromised performance for aHi-Fi (High Fidelity) music. In class A, the ampli-fier is in full conduction and consumed much power,it is the best performance in terms of distortion (high-est music fidelity). In class B, the amplifier is offconduction and will conduct only when there is asufficient audio input signal, making less powerconsuption but notorious in distortion (lowest mu-sic fidelity).

To compromise between usage of power and mu

Heart Systems V1.0


INTERFACEKEYs

EEPROM

8051 / AVRcoreMCU

ISP ProgrammingIR

UART BLUETOOTH

MCUINTERFACE 20 x 4

LCD

Left

Right

DR100W_PA DR100W_PM

Left

RightLeftRight

SPEAKER

SPKR OffsetVoltage &Detection

MCUINTERFACE

Power RELAYStandby

MUTE &STANDBY

Left Right

StereoInput

DR100W_EQ

DigitalVOLUME

MCU INTERFACE

PresetEQUALIZER

Left

Right

Left Right

POWERAMPLIFIER

I2C

I2C & Logic LevelSPK1

SPK2DR100W_PM

Figure 4 : THE DR10W conCEPT Detailed Diagram


Heart Systems V1.0



sic fidelity, the class AB scheme is born. If youheard the stereo of your neighbor sounds so good,that is called Hi-fi or High-Fidelity. If, in some in-stances you heard your neighbor complaining be-cause of a 3rd party involved in their relationship,that is called “infidelity”.

So what is Class D? I bet - “D” means digital, notthe big Daddy-D at 1diy. Class D comes with digi-tal processing, not like the class A,B, AB, G and Hand other class which are analog processing.

If it is called digital - it process digitally, and whatbenefit we can get, if it is process digitally? It im-proved the efficiency, the input power from thetransfomer is processed at about 90%, which lesswaste of power loss during the amplification , ascompared to analog processing of about 45% effi-ciency.

In DR100W_PA, we voted the Philips solution(NXP), a chipset claimed to delivered 100Wrms/channel at a specified test condition. The chipsetis the TDA8920BTH - a class D digital amplifier.

There is also called class T. This is another audiodigital amplfier with different digitral processing tech-nology, known as Tripath’s propriety Digital PowerProcessing (DPPTM) Technology, how is that?Google the TA2022 Tripath chipset to know moreabout class T.

How Class D AmplifierWorks?

Philips documented the TDA8920BTH in detailed,pin description, block diagram, processing defini-tion and applications circuit.

I would suggest that you should refer to this docu-ment, TDA8920B (do not use the TDA8920, itshould comes with a “B” like, TDA8920B), that is a34 pages to read and know about the Philips (NXP)TDA8920BTH - digital class D power amplifier.

How Class D differsfrom Class ABPersonally, this is just my own understanding (so,please, if I am not right, please send an email [email protected] and correct my mis-take - “salamat”). Let’s see the block diagram ofanalog process and digital process as shown inFigure 5.

Analog Process:The simplified illustration of analog process is shownin Figure 5 - a. The input signal of sine wave is fedinto the amplifier input stage, it then increased inamplitude by the Driver stage and finally fed forpower amplification by the Output Stage. The out-put stage will generate heat in processing the re-quired amplitude, it requires a heatrsink to effec-tively dissipate the heat, the bigger the heatsinkthe faster the ehat dissipate. If the heat generatedon the output stage will not dissipate and it willcontinue build up, a thermal run-away might occurwhere the output stage will damage. Most ICamplifier have a thermal sensor that will shut downthe amplifier when overheat occurs.

Digital Process:For digital processing, the same sinewave is fedinto the amplifier input stage, the analog siganl isconverted into Pulse Width Modulation (PWM) thenfed into the Control and Handshake block to drivethe High Driver Stage. An external low pass filter isrequired to recover back the digitized analog am-plified sinewave before it can be fed-in across thespeaker.

What is remarkbly noticed with digital amplifier isthat, the heatsink are small, due to the fact that,digital amplifier process the input power by about90%, it means, close 10% is generated as heat,so it reauires smaller heatsink or no heatsink re-quired at all. While in analog process, it requiresheatsink because about 50% of the input power iswaisted and converted into heat.

A good example between analog and digital pro-cess is the Linear and Switch Mode Power Supply(SMPS), the Linear Power supply requires heatsinkto dissipate the wasted power while the SMPS re-quires very little heatsink.

Heart Systems V1.0


Figure 5 : Analog versus Digital Process


InputStage

DriverStage

OutputStage

InputStage

ExternalLC

Filter

PulseWidth

Modula-tion

Control&

Hand-shake

HighDriverStage

Heatsink

(a) Simplified illustration of analog process of power amplifier

(b) Simplified illustration of digital process of power amplifier

Heart Systems V1.0



DR100W_PADesign Source:The DR100W power amplifier schematic diagramis shown in Figure 7. It is basically the same asthe recommended by Philips on Figure 9, page 21of the Philips datasheet.

Well . . . . . Philips makes our design work easyby offering recommended circuit, sounds like plugand play design, making the design EASY, FASTand FUN (but not Affordable since this IC still ex-pensive to us) not like in the 70’s - you start fromscratch. China market offer the component sys-tems . . . . making the whole thing easy.

A “bit” explanation how the TDA8920BTH works according to the DR100W designThe DR100W_PA solution is highly Integrated so-lution packed into a single IC in HSOP24 SMDpackage, see Figure 6 below.

The stereo input signal is fed into the input stagevia pins 8,9 and 5,4 for stereo, and it is internallyprocessed. I do not know “exactly” the signal be-ing processed under the blocks of PWM, Controland Shake and the High Power Driver Stage. WhatI know is that, the analog input signal is convertedinto a PWM with carrier Frequency between 300KHzto 350KHz.

The input signal which is converted into PWM willthen passed to the Control and Handshake blockto drive the High Power Driver stage to provide highlevel switching signal about the same level as thepower supply.

At +28Vdc supply, the output signal at pins 16(and 21) is high power PWM about 28Vrms asshown in Figure 8.

Figure 6 : The TDA8920BTH HSOP 24 Package

From the output waveform, we can see how thePWM react to a varying sinewave input signal. Thewaveform in Figure 7 is low input signal (low level),the waveform shown in Figure 8 is medium inputsignal,

Figure 7 : The PWM output at pin 16

Figure 8 : The PWM output at pin 16 at medium input signal

The waveform in Figure 9 is relatively high inputsinewave signal causing the output nearly at clip-ping. Now, can you see the difference how thehigh powered PWM looks like? We have idea nowhow the processing inside the IC.

Heart Systems V1.0

PRELIMINARYdigital power amplifier moduleconCEPTDR100W

Equalizer, Tone Control, PowerAmplifier, MCU Programming

Another thing you might notice in Figures 7,8 and9 is the Vrms voltage of the PWM, as :

Figure 7 : 28.0 VrmsFigure 8 : 27.9 VrmsFigure 9 : 25.8 Vrms

At low input signal, it consumed just little powerfrom the Power Supply, at high input signal, thesystem will draw large power from the power sup-ply, unfortunately my power supply cannot deliverthe power required by the TDA8920BTH, so thevoltage will drop, the result of this is that, theTDA8920BTH cannot deliver the real power to theload. I conclude then that, a good Power Supplyis required to drive the TDA8920BTH into full power.

Now, the output of TDA8920BTH is high powerdigital PWM as shown in Figure 7,8 and 9 cannotbe used to directly fed into the speaker, otherwiseyour speaker will complain of feeding him an un-clean sinewave signal, just like a baby is expect-ing a milk where in fact you give him a vodka (whata wild explanation, I guess) the baby will definitelycry, for your speaker I guess it will heat up andeventually burned the voice coil.

To return back the sinewave signal, it need a 2ndorder LC filter, the result is shown in Figure 10,indeed, a boosted replica of the input signal.

Figure 9 : The PWM output at pin 16 at nearly the maximum power

What I noticed is that, if you zoomed the signal,you see that, there are other signal “ride on” intothe sinewave as shown in Figure 10, I tried to cap-ture it but then, my camera gone crazy, wheyyyy!see Figure 11.

Figure 10 : Signal across the 4 ohms Load at mid power level

Figure 11 : extra signal across the load

Zoom waveform to see the extrasignal ride on into the Sinewavesignal

Figure 12 : further zoom

Heart Systems V1.0



Actually, in real world, the LC filter did not filter out(removed) all the high frequency carrier of the PWM,a 349 KHz signal still “ride” into the 1KHz sinewave,and eventually it fed into the speaker.

Is this good or bad? Definitely it is “not desirable”.This can be minimized by adding another filter whichwill further “filter” the high frequency. With theDR100W_PA design, the system is not perfectbut it can function as it was intended.

The 349 KHz cannot be heard by our ears, it willnot contribute also as high frequency noise (I amtalking to the DR100W_PA hardware including thePCB design), thus, it is accepted.

Here, an output signal of the DR100W_PA whenboth channel driven by 4 ohms load with SMPSpower supply. See Figure 13.

This waveform give us an idea how clean (how dirty)the waveform at a certain voltage swing (6.18 vrms)at the load. This voltage swing at the load pro-vides real power of 9.8Watt for that channel, thatis, 6.18x8.18 / 3.89, my load resistance accord-ing to my ohmmeter is 3.98 ohm. Oh! This is notthe maximum power it can deliver, its just a mid-level power for “soak test” - a test condition thatnormally we used most of the time. This test per-form for 24 hours (1diy standard) and yet, we got awarm heatsink temperature. Oh yeah, 20Wrmsstereo at your home is enough for most users.

Disecting the Design :I should say, lets have the design review............

(a) Removing non-standard capacitorThe design can say low cost, since it removed thoseexpensive components. In the Philips document -Figure 9, page 21 - application schematic, theCapacitor C8, C16 and C38 were removed.

These capacitor requires higher voltage more than60Vdc, for the standard capacitor voltage value inthe market, perhaps it is 20Vdc, and it is expen-sive.

Figure 13 : Output signal - both channel driven at 4 ohms load, how clean the voltage

swing at the load when using a SMPS as power supply and soak test for 24hrs

Figure 14 : Low cost design by removing the high voltage capacitor

Heart Systems V1.0


(b) Removing the Ferrite Bead at Supply LineThe Ferrite Bead were also removed, please seeFigure 9, page 21 - application schematic, L1 andL2 Bead.

In our applications, the filter used is 10,000uF / 35volts.


These components were intended for Power Sup-ply filtering. What is the expected effect after re-moving these components? Well, it remains un-known and to be known after subjecting into anintensive testing including reliability test.

(c) Protection CircuitIn the DR100W concept - this is called ProtectionModule or DR100W_PM. This is a circuit blockthat will prevent the speaker from damage whenthe amplifier gone crazy -- when the dc voltageoutput at the speaker (dc offset voltage) is higherthan what the speaker can handle (frankly, we havenot experienced yet our DR100W amplifier to acti-vate the protection circuit).

Let see the circuit in Figure 7. Google is reallycool, please use it to download the PC1237 or theNTE7100 document because it will help us a lot inthe explanation - a details information can be foundon the datasheet.

In our applications, we decided to use +12V a regu-lator power supply using the LM7812, though theIC can be used up to 60Vdc.

The interesting part here is the Overload function(pin 1) which I am interested how it function andwhat it can do - - - it is unfortunate that, due topatent problem (see page 5 of the NEC document),it is not included.......... The team redefined thefunction of this pin, it says that at 0.6V, it will latchup the relay (break the relay -- like disconnectingthe speaker from the amplifier). Using a TTL signalfrom a MCU of the DR100W_CM, we can com-mand the Protection Module (PM) to forced to dis-connect the speaker from the amplifier by sendinga logic 1 signal, and, at standby mode, we cansend a logic 0 so that the PM will not consume toomuch power.

If you have other external application circuit thatmake pin 1 to function as it was originally con-ceive, or you designed a circuit that can make itwork to “protect” the speaker like Clipping detec-tion, I would be glad if you can share it with us,thank you.

Furthermore, we wanted that every module is su-pervised by the DR100W_CM, our prototype useMCU to reset the PM via its pin 3. When the pin 2detect “+” or “-” high offset voltage, it will discon-nect the speaker. To connect back the speakerwhile making it sure that the dc offset voltage isnot preset, we used MCU. (Actually - is a part ofthe Learning process discussed on DR100W con-cept) but then, we learned that, the uPC1237HAcan do that by itself, so, we let this IC handle theresetting for simplicity.

We used the reset, that, when the dc offset is gone,it will latch (reset itself) without any external trig-ger. The other reset available is that, you need toreset the Protection circuit - power off and poweron the supply.

Figure 14 : Low Cost design by removing the Inductor bead at the power supply

Heart Systems V1.0



C210000uF35V

C110000uF35V

R310

Vdda

Vddp

Vssp

Vssa

23

20

17

14 Vddp

Vssp

1

3

12

10Vdda

Vssa

C190.1uF

C200.1uF

C210.1uF

21

22

16

15

Figue 15 : Schematic Diagram - Amplifier Section

VsspVddpVsspVddp

C220.1uF

C260.015F

C230.1uF

C250.1uFC24

0.1uF

C270.68uF

C30220pF

C29220pF

C18220pFC17

220pF

C160.68uF

C150.1uF

C140.015uF

9

C7220pF

C6u47F

C9u47F

R65K6

C8220p

5

4

C12220pF

C10u47F

C13u47F

R75K6

C11220p

8

VsspC50.1uF

24 19 13

8

7

Vssa

RoutLout

2 11L

RG

C30.1uF

R55K6

R430K

C40.1uF

IC1TDA8920BTH

AC

ACGND

R110 R2

10K

R85K6

R910 R10

10R1110 R12

10

VR110K

ac1

ac2

Mode

6

Please refer to PhilipsSchematic Diagram,

Figure 9, page 21 of theTDA8920BTH datasheet(this schematic is not

yet verified by ourTeam)

L1

L2

CON1

CON2

LED1RedD1

1N4007-T

C280.1uF

C310.1uF

22uH

22uH

Heart Systems V1.0



Figue 16 : Schematic Diagram Speaker Protection Section

C35100uF35V

1 2 3 4 5 6 7 8

R1647K

Overload

Latch / Reset

Offset D

etect

AC O

ff Detect

GND

Relay D

river

Vcc ON

VCC

R153K3

R1847K

R1947K

Rout

Lout

C39100uF16V

+12V

ac2

ac1

+12V

D31N4007

D41N4007

D51N4007

IC2LM7812

IC3uPC1237 / NTE7100

C38100uF16V

C374u7F16V

SPK14 Ohms

SPK24 Ohms

RLY1Relay

R1710K

+12V

C364u7F16V

Mode

R135K6

R145K6

Vssa

D25V6

C31100uF16V

Please refer to NECuPC1237 SchematicDiagram and applica-

tions, This schematic isnot yet verified by our

Team)

CON3

Heart Systems V1.0



DR100W_PAPower Requirements

According to Philips specifications, you must usea voltage of +/-12.5 to +/-30Vdc for the operation ofthe TDA8920BTH.

That is the voltage, what about the current? Thespecifications did not “really specify” the currentneeded to produce a desired output.

For example, it says that, at +/-27Vdc with 4 ohmsspeaker load, you can get 86W with a 10% distor-tion, again, what is the current needed? Or, whatwould be the transformer current rating to producethis power?

Our visiting friend (a former 1diy member) makehis hand dirty on our work bench, his test showwith different power transformer as shown in Figure17.

He noticed that, EI and Toroid transformer will tendto decreased the voltage being supply to theDR100W_PA board at maximum power, he con-cluded that, these power transformer cannot de-liver the exact “power” the TDA8920BTH requires.(Pertaining to our transformer only, EI core = 18-0-18Vac @ 3 Amp., Toroid = 20-0-20Vac, 250W,SMPS = 30-0-30Vdc @ 3.5 Amp)

Please note, however that, this is only true at maxi-mum output signal, where, in reality, you will notgoing to maximized your power amplifier alwaysfor a normal listening pleasure, unless, you are inthe battle of the band and strictly hate that yourPA cannot deliver 100Wrms per channel.

Only the Switch Mode Power Supply (SMPS) candeliver the greatest power, but still cannot obtainedthe 100Wrms per channel at 4 ohms load (200WrmsStereo) as specified by DR100W conCEPT speci-fications, not even the Philips (NXP) specificationsof 86Wrms per channel.

Well.... well... well.... I will leave that for the Tweakand Modifications (if there is any) - something thatwe can diy to do - to perform trial and error modifi-cations with an aim to improved it.

Figure 17 : Using different transformer to power the DR100W_PA

Heart Systems V1.0


DR100W_PA Tweak & Modification

The DR100W power amplifier circuit design is notperfect in terms of performance and specifications,thus, a room for improvement is “waiting” on tehcurrent design.

If you like to make it the best, you need to adjustsome component value, perhaps add componentsand see if you can benchmark or supass the Philipsspecifications described in their datasheet.

Those values and modification, we do not know yet,but we will play around with this module, we willdo Trial and Error to make it the best - at least tomy level and expectation as diyers.


DR100W_PA conCEPTRequirement for PAThe DR100W conCEPT requires that, the poweramplifier can be controlled with :

(a) Standby(b) Mute

In Figure 16, you can find the mode control but notspecified exactly how to use it. Going back toPhilips datasheet, on page 21 Figure 9, pleaselook at S1 and S2, when S2 is close which forcedpin 6 to logic zero, the amplifier will be in thestandbymode.

If S2 is closed, the mode pin will be in Mute state.By design, we can also perform a digital mute onthe part of the DR100_EQ - which we believe abetter choose of mute. Real life applications willdictate which mute will be used.

Mode

R145K6

Vssa

D25V6

C3147uF16V

R135K6

Rs100

Rm5K6

Mute

Standby

Intel 8051Core MCU

DR100W_CMControl Module

Figure 18 : Implementing Mute and Standby control on the DR100W_PA circuit

Standby mode

active mode

Heart Systems V1.0



Diy Constructing theDR100W PA

Here we go............. make our hands dirt, readyfor the manual insertion and assembly.

<<<<sorry for the inconvenience, the assemblyinstruction is under cooking, we will publishedvery soon>>>>>

To be Continued.......

Heart Systems V1.0



APPENDIX

Page i

Heart Systems V1.0



DR100W conCEPT Learning Platform

Heart Systems - the “tiny” company located inBaguio City, who established the 1diyTeam, pro-mote & support : diy Learning, it created sev-eral low cost Trainer Kit platform generally forlearning hardware design and interfacing, MCU pro-gramming and systems integration - - targettingthe Starters with zero background.

The DR100W conCEPT is the latest platform inthe field of Audio and Music reproduction.

What do we have here? The conCEPT will let youlearn the following :

Audio :Equalization reproduction with different mode ,Rock, Classical, Pop, Jazz (hardware)Effects : Turbo Bass and 3D SoundBass and TrebleDigital gain, volume and balance controlDigital Power Amplifier

Hardware :Digital processing technique control by I2CAnalog and digital InterfacingModular and Systems IntegrationSolutions to Noise and IssuesHardware and Software compromise and optimizationHardware assembly / debugging

MCU Programming (Software) :Man Machine Interface (MMI) implementationI2C Protocol and logic control, UARTLCD DisplayingProgramming technique and problem solving

Testing :Parametric Test, Tone Control signal testingHardware & Software Test / Reliability TestAutomatic Test Equipment (ATE)

Project Management:Project MilestoneLadder Systems Product Development

We are talking to our brilliant fellow hobbyist tohelp us to deliver this Trainer Platform.

Digital Audio ToneControl (DATC) Trainer KitDigital Audio

STARTERMCU-EB8051Assembly LanguageGeneral Trainer Kit

H o b b y i s tCentral OfficeS i m u l a t o r(Hob-COS)Trainer KitTelephony

Night Eyes SecuritySystems V2(NE2ss) Trainer Kit (Security)

Figure i : THE 1diy Learning Platform - Proudly made by true blooded hobbyist for the

general Hobbyist courseware & shareware

Page ii

Heart Systems V1.0


Page iii

Photo Gallery :

Engineering Design - LSPD1 :Digital Tone Control and Volume Control

Engineering Design - LSPD1 :Checking the Equalizer Performance

Engineering Design - LSPD1 :Writing its program Hand Made Sample - LSPD2 :

The finished EQ on its standard PCB

Hand Made Sample - LSPD2 :Testing the EQ with Avril Lavigne Concert


Heart Systems V1.0


Page iv

Hand Made Sample - LSPD2 :Testing a candidate Power Amplifier : Class AB

Hand Made Sample - LSPD2 :Testing a candidate Power Amplifier : Class D

Hand Made Sample - LSPD2 :Let’s see some MMI (Man Machine Interface)


Final Sample - LSPD3 :Testing the TDA8920BTH : Class D TDA8920BTH

Final Sample - LSPD3 :Testing the TDA8920BTH : Live Audio Test

Final Sample - LSPD3 :Testing the TDA8920BTH : Soak Test

Heart Systems V1.0


Page v

Kit Version :The 1diyTEAM create an investment to get the com-plete materials for the DR100W conCEPT - spe-cially packed for Audio Hobbyist who would like tobuild the DR100W, Learn Software programming,systems integration, solving issues such as noise.. . . . . . . . . . . in general - anyone who would liketo feel and experienced the adventure with theDR100W conCEPT.

The Kit version will include the major hardware,such as :

a) Equalizer : EQb) Control Module : CM

and you can select the Power Amplifier Module (PA)based on your preference Power Output :

a) 10W Stereob) 40 Watts Stereoc) 200 Watts Stereo (official PA)

Feedback :We thank those guys who will feedback about ourDR100W conCEPT. I’ll be glad to hear from yourcomment, improvement and redesign - makingthe DR100W conCEPT a better Trainer Kit :[email protected]

d’ TEAM :Thanks to these guys - the dr100wTEAM :

Project Manager /Systems Architecture : F. DandySystems Integration : ArielSoftware Engineer : RomelTest / Hardware Engr. : Bryan / NoliMaterial Sourcing : Anna Chen

http://www.1diycentre.com

Final Sample - LSPD3 : 2 Channels DrivenTesting the TDA8920BTH : Max Output before Clip*** over voltage beyond supply max limit test ***


Final Sample - LSPD3 :Testing the TDA8920BTH : EI Transformer

Final Sample - LSPD3 :Testing the TDA8920BTH : Torroid Transformer

myhobby Educational TrainerEAF2 Electronics SeriesHeart

Systems

Heart Systems V1.0


Powered by :

Powered by :

Powered by :

Powered by :

Powered by :

HEART SYSTEMS

HEART SYSTEMS

HEART SYSTEMS

HEART SYSTEMS

HEART SYSTEMS

Digital Audio Tone Control.............................................

Digital Audio Tone Control( DA( DA( DA( DA( DATC )TC )TC )TC )TC )

------- DATC Version 1.5 -------

The Digital Audio Tone Control (DATC) isanother Educational Trainer - Project fromHeart Systems. The DATC can be use as aTrainer Kit for studying the 8051 core softwareapplication on digital Audio. The 8051 proces-sor is In-System Programming with 8K bytesof Flash Programmable ROM.

DATC Features:- MicroProcessor Controlled using the ATMEL AT89S52 (PLCC)- Using Digital Audio Processors : SGS Thomson - ST TDA7442 with Surround Effects- Push button adjustment of Volume, Bass and Treble- Push button Power On/Off- Push button Music / Surround Selection- Infrared Remote Control- 16x2 LCD with amber backlight- Stereo VU meter (optional)- Stereo Internal Headphone amplifier- 14 dB of Boost/ Cut Treble- 14 dB of Boost/ Cut Bass- Music Surround Sound On/Off Selection- Mode : Music / Simulated- 4 Stereo Inputs - RCA Jacks- 1 Stereo Outputs - RCA Jacks- Last Setting Memory- Real Time Clock- Programmable Turn on (automatic turn on)- Programmable Turn off (automatic turn off)- User's Programmable Control (User can program the Processor)- MCU programming on board (ISP)- External Control via Relay of amplifier Power Supply- External Control via Relay of Amplifier Speaker Systems- Power Supply Requirements : 12 Vdc @ 500 mAmps

Revival DATC

DADADADADATCTCTCTCTC m ym ym ym ym yfriendlyfriendlyfriendlyfriendlyfriendlyTone con-Tone con-Tone con-Tone con-Tone con-troltroltroltroltrol

my DATC

do diy MP3 Player for DATCdigital Tone Control

1diy issue18 dr100w pa

Documents