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Muhammad Abu Bakar

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Posts posted by Muhammad Abu Bakar

  1. Dear Friends,

    I have got to power my laptop from a 12V battery. I have a couple of ptn04050 dc/dc converter modules lying around. The converter operates at 5v and boosts it to -15V (adjustable). Could I use it to get 19V?

    My first  thought is dividing the Battery voltage to 6V using capacitor divider and then drive the laptop with ptn04050 output in series with battery. Please give your suggestions.

  2. Cascade ?: one way is to connect c_out to c_in of the next one
    or else if u want then to count in sequency, try

    May be use 1 master 4017 which gets 1/10th of system clock and its output used as display en-able for all other '17s which are all clocked from same (I say system) clock. Unfortunately disp-en function isn't onchip so u have to plan ur external circuit. Transistors could be used to power individual '17s.

  3. Aslam O Alaikum Shaiq,

    Why not use the centrifugal force of a body rotating in circle. Acutual mechanical may consist of a continuously rotationg arm. Rotating at one end with a hand on the second end. Hand grips the ball till ball's w is sufficiently high and then release the ball. Analogy of the game where a player throws the hammer first by rotating himself in circular motion.

    I think this way you'll need lesser force to grip the ball while ready to be released than the case in which you apply a force to push the ball. I mean a plunger type grip.

  4. Hello!

    I am also an EE. I graduated 6 months back and immediately got a telecom job as  Management Trainee. I have great interest in electronics but can't do more than enjoying it as a hobby.

    The days of an EE designing a new circuit or troubleshooting complex systems is long gone

    I had never much of this kind of work in my country. But I never thought that you can't find a Design Job of your interest anywhere else :-[
  5. Hello Mike

    Just like most people like to mount through hole parts all on one side of the PCB and call it the top.  If a part doesn't fit one way, why not try mounting it from the bottom? Presto, a reverse pinout!

    I realy do so. Once I had PCB's printed from wrong side(acutually flipped). Then I had to solder DIPs at the bottom side. However I got ZIPs on top side with moving the legs at opposite sides.

    About the matter of IC pins I personally feel:

    1. All i/p pins should be grouped togather (Mechanicaly in a row).
    2. All o/p pins should be grouped togather.
    3. Power supply pins should be neighbours.
    4. The pins performing control functions should come in line.

    Perhaps it might put PCB designers on a Holiday  ;D
  6. Hello!

    I have found a power supply which has some fault, so I need its circuit details. The information written on one of the stickers is:

    Ericsson                      LZF083 60/2L RB
    Article Code                  BMJ 141 020/31
    R-STATE                          R2A

    FACTORY                      YEAR                      PERIOD
    A8                                  93                          15

    Please help me!!!

  7. Then you have a faulty stepper motor or some other kind of motor! Stepper motors will even whiteout shorting the wires have clearly noticeable steps, and when shorting the leads it will be very sluggish! Unless of curse the magnets or the windings are gone, then it will spin easy!

    Yes my stepper motor whiteout shorting the wires have clearly noticeable steps. I have experienced difficulty in spinning the motor while on. But just shortning the wires has no effect. Ante have you experienced it yourself?
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