Search:

Type: Posts; User: betwixt

Page 1 of 20 1 2 3 4

Search: Search took 0.11 seconds.

  1. Closed: Re: PIC serial port receive Problem, please help

    Remove the two lines that contain 'GIE', they are not needed and could cause other problems including possible 'deaf' periods where serial data is lost.

    I think you are trying to capture all the...
  2. Closed: Re: PIC serial port receive Problem, please help

    Are you confusing FT232 and MAX232 perhaps?

    FT232 = serial to USB converter
    MAX232 = Voltage level converter usually used in serial TTL to RS232 applications.

    Normally you don't need a voltage...
  3. Replies
    12
    Views
    315

    Closed: Re: Problem with using ic uA733

    What puzzles me is the pins of TX1 suggest it is a metal can package with pins to fit a 14-pin DIL profile. That almost certainly means it produces TTL level outputs. If I'm right, TX1 pin 8 should...
  4. Replies
    7
    Views
    246

    Closed: Re: IC TDA2004R Electrical specifications

    TDA2004 was never a good device. It was designed to go in low cost record players and tape recorders. I think it went out of production in 1996!

    The specifications shown are "Absolute maximum...
  5. Replies
    10
    Views
    432

    Closed: Re: CRT Hitachi turns off

    That is a good sign, for the scan to be full width but that voltage so low indicates a problem in generating the 200V line. The lower that voltage is, the brighter the screen will be and the less the...
  6. Replies
    3
    Views
    156

    Closed: Re: LT3083 lab PSU question

    1K is fine if 1V is the minimum output. There is an explanatory note at the bottom of page 1 showing 909 Ohms for 0.9V.

    The instability could be due to several things, as it has a floating...
  7. Replies
    10
    Views
    432

    Closed: Re: CRT Hitachi turns off

    Sorry for the delay, I've spent the last day in hospital so I couldn't write back!

    I suspect the problem is the +200V supply to the video amplifier stages is missing or has dropped very low. ...
  8. Closed: Re: PLL and LCD: LCD shows garbage while PLL is used

    Likewise but I wonder if the PLL in question is the internal clock multiplier. It would be useful to have some more information.
    If it is the internal multiplier, the chances are the timing signals...
  9. Replies
    3
    Views
    156

    Closed: Re: LT3083 lab PSU question

    Are you observing the minimum load current requirement as shown at the bottom of page 3. The load current must be >1mA over the whole voltage range you have under your control. Basically, add a...
  10. Replies
    3
    Views
    246

    Closed: Re: Looking for a single SMD pin header

    Why not simply use copper pads?

    Brian.
  11. Replies
    5
    Views
    264

    [PIC]Closed: Re: Code for dspic33fj32mc204

    You didn't look very far. There is a register in that device specifically for setting PWM deadtime. Look at page 170.

    Brian.
  12. Replies
    3
    Views
    252

    Closed: Re: Specifications beyond data sheet...

    No guarantees of course but I would guess it would work over quite a wide range. The lower limit is usually decided by internal gain dropping due to capacitors in the silicon, the upper frequency by...
  13. Replies
    10
    Views
    432

    Closed: Re: CRT Hitachi turns off

    I've traced the schematic. My first guess is C756 is faulty.
    Do you have a voltmeter if I ask you to take measurements?

    Brian.
  14. Replies
    10
    Views
    432

    Closed: Re: CRT Hitachi turns off

    Those a 'flyback lines', it's the dots that normally make the picture as they scan back to the top of the screen ready for the next visible raster. They are spaced out because the sweep back to the...
  15. Replies
    10
    Views
    432

    Closed: Re: CRT Hitachi turns off

    Can you post a picture of the horizontal lines or at least describe them please.
    Are they overlayed on a normal picture or are they against a bright background?

    Brian.
  16. Closed: Re: Need to ensure SMPS output filter has at least 10mR of ESR...use "ESR resistor"?

    One milliOhm is incredibly small, the chances are the ESR of the capacitors is higher than that already and the added resistance of the connection to it will make up any difference anyway. I don't...
  17. Replies
    13
    Views
    648

    Re: learning to detect radio signal.

    A spectrum analyzer would be a far better instrument for measuring at those frequencies!

    Brian.
  18. Replies
    13
    Views
    648

    Re: learning to detect radio signal.

    You stand absolutely zero chance of a multimeter reading that!

    Consider that when using frequencies in that range you need at the very least coaxial cables and more likely matched strip lines...
  19. Closed: Re: Questions of mechanical to electrical energy transfer

    Follow Brad's advice but please bear in mind that nobody makes a 'dynamo' charger specifically for the voltage and current you need. I cases like this you generally have to add some electronics to...
  20. Replies
    13
    Views
    648

    Re: learning to detect radio signal.

    Yes, an ordinary meter will measure voltage up to its maximum frequency. Typically for DVMs that will be a few KHz.

    You can rectify the signal and measure the resulting DC, this is how "field...
  21. Closed: Re: Rectifier diodes with bypass capīs & gounding speaker basketīs

    That is just a normal toroidal transformer with primary and secondary on different bobbins. That construction is normally used when very high voltage isolation is needed between primary and secondary...
  22. Replies
    6
    Views
    334

    Closed: Re: Repeat Cycle using timer application

    I'm still confused about what this code is supposed to do and in particular how it produces the display. Am I correct in thinking the lines:

    #define DISPCLK RB5
    #define DISPDATA ...
  23. Replies
    35
    Views
    875

    Closed: Re: uc3842/3843 Vcc problem in smps.

    Looking at data sheets and application notes, the snubber capacitor values range from 3.3nF up to 10nF, 103pF still seems unreasonably low to have any significant effect.

    I see some designs using...
  24. Replies
    35
    Views
    875

    Closed: Re: uc3842/3843 Vcc problem in smps.

    If the schematic is to be trusted, shouldn't C1/R2 be across the rectifier?
    Is D5 doing anything?
    103pF in the snubber circuit seems far too small, should it be 1nF?
    All other points made by...
  25. Replies
    6
    Views
    334

    Closed: Re: Repeat Cycle using timer application

    I explained the timing issues to nayakajit87 and how to structure the ISR efficiently in a previous post but it has been ignored.

    As well as that, I can't see where 'LED_MS_Flag" gets reset...
Results 1 to 25 of 500
Page 1 of 20 1 2 3 4