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Posts posted by faizanbrohi

  1. Well in my country there are no Radio cops to whom i have interferance . so no problem there. about the R5 resistor yes the other end is backwards ,well i guess i have to redaraw the schematic and PCB with your settings now lets see .

    ok i will use a 0.1uf because i have one . for the inductors . well they are not the actual values i have approximatied them , please see the original website and see how they are made. And for The transistors , i think i will go with BF199, MPSH10, BF240 , 2N3926 , MRF237 will do fine as all are RF Transistors. i think bf199 and bf240 are fine RF Transistors and easy to find.

  2. Here is a PCB layout and shcematic for my latest TX-500 500mW FM Transmitter i am building for my RC Remote controlled car using DTMF Signals to control it .
    I have not build it but this will hopefully be my 3rd transmitter project . from 40mW and 10mW to 500mW . Well hope this works . I found the schematic on www.electronics-diy.com and then redrawned it and made a PCB . Later i will make the Reciever and the DTMF Encoder and Decoder.

    THere is one problem the 4.7uF capacitor is i think a non polar  and the 47uF is also a non polar capacitor but well i can go with a 4.7uf to be non polar but a 47uF , i don't think so or it might be bipolar.

    The Red connection on the PCB Layout is for a jumper that was not routed correctly . it might be connected on the bottom side using insulated copper wire.





  3. Hello Everyone , this is faizanbrohi again to discuss yet another project design . actually it is related to building a Power supply for car audio using a IC UC2577-ADJ and fits the need Perfectly for a 12V battery step up psu.

    Main Page : http://focus.ti.com/docs/prod/folders/print/uc2577-adj.html
    Datasheet : http://www-s.ti.com/sc/ds/uc2577-adj.pdf
    Application Note : http://www-s.ti.com/sc/psheets/slua181/slua181.pdf

    The application note discusses a supply for a automotive application but has less voltage specification and less current specification . The absoulute maximum rating is good for my design as i require +55V and -55V @3A or @6A so since this is a single mode supply , We can make two identical units and then joing them serialy like two voltage sources producing +55 and -55V . Sounds Really Good , But SOme Calculation is needed . The Datasheet is very comprehensive in providing the adequate information for each and every thing. THere is only theoratical Calculations THat need to be done .

    The Pictures For the Block Diagram are included and the Absoulte Ratings along the Note .



  4. i think a evaluation board is neccesary to implement this . but the problem is that i cannot buy the evaluation board in my country , one of my relatives live there in toronto but i bet they don't know the location , audioguru you also live in canada , can you check out the Texas instruments distributer in toronto and look if they have an evaluation board for the TS5152 - 5508 , because iin the texas instruments site , it only says status : PREVIEW for it . but you can buy it from the distubuter , better go check it out... thnx

  5. Hello and i am really really happy today it was raining. i enjoyed the rain very much . after all those warm and humid days , finally the weather is really good now .

    Well Here is a look at the LM3915 again , and now it is is using DC 12V with a half wave peak detector circuit . i am just asking if the sensitivity can be adjusted and since it can , will it work good when connecting it to the TL071 preamp .
    THere is one dotted line , does it need to be shorted or not??


  6. Well HEllo again , i have modified the schematics and well here is a schematic for the bass and treble control and the Aduio VU LED Meter , i want to keep the circuit as simple as possible. because i don't have enough space.

    So , the first circuit as you said i have used the input coupling capacitor of the preamp to the bass treble control and then back to the audio taper / power amp .

    The second circuit is a simple LED VU Meter because i just want to use a it after the Preamp , so is there any problem.



  7. Well Hello again Audio Guru  , how r u . well i have built the power amp successfully , now i am thinking to add flavour in it and found some problems with my flavours . One is the Bass and Treble Control and the other is a Audio VU meter , i want to keep the circuit as simple as possible . here is a illustration for it , as you can see in the first diagram , i not need first opamp as i have the preamp control and i don't even need a mixer after the bass treble control because there is only one input , and my amp is mono.  FOr the second circuit it is using AC , i don't have any ac input , only DC from other Power supply , can i use dc for its VCC and i also need a dual VCC - and + so i will use a ICL7660... So any suggetions ideas .



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