ILL HELP YOU WITH ELECTRONICS QUESTIONS

MY WEB SITE IS HTTP://BBOOTHE.VR9.COM


EMAIL ME WITH ANY QUESTIONS YOU MIGHT HAVE




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  • : MY WEB SITE IS HTTP://BBOOTHE.VR9.COM



    : EMAIL ME WITH ANY QUESTIONS YOU MIGHT HAVE

    :

    :

    Dear Dr. Boothe,

    I need some help. I'm building an infrared mouse. I got problem for transmitting infrared pulse with high enough current while maintaining the pulse's DC for 50%. My transmitter system using micro AT89C2051 as controller. It uses +5Vdc power supply. The micro read 6 input buttons and transmit the button status trough serial data transmission. The transmission at 2400 bps, 8 data-bits, 1 stop-bit, no parity. Output port from controller connected with a 555 timer. The timer act like modulator. The NOT gate is placed between port and 555 timer. The gate function is to prevents false transmission of pulse when no data trasmitted from the controller. (The UART of controller maintain the serial output port in logic high when no data is being tranmitted.)

    I'm using Harris 7555 timer.

    The 555 timer is designed to transmit 40 kHz square wave pulse with Dc=50%.

    The output gate connected with pin 4 of 555 timer.

    pin 2 and 6 tighted together with a 4n7 capasitor to ground. The 1k ohm R and 10k VR connected in series. One side of the R is connected to pin 3, and the other side of VR is connected to pin 2 & pin 6. From calculation the timer can produce a square wave CD=50% with freq bettween 17 kHz to 96 kHz. The transmitter is tuned in 40 kHz.

    Output pin 3 of timer (+4V when high) is connected with pin GATE of MTP3055E. Pin DRAIN is connected at +9Vdc. Pin SOURCE with two IR LED in series to ground.

    I use the mosfet to get enough current for driving my IR LED. When measure the output pin 3 from timer using oscilloscope, it supposed to be 50% DC 40 kHz square wave. But I got unreadable freq (it's like osilation) and DC around 60 - 75% with voltage level of +4V.

    I've check the osciloscope setting, the circuit, the mosfet and replace the timer. But I got the same waveform. The output current from pin Source is around 120 mA. It's quite good.

    Why I got such waveform? Is there something missing with my circuit? Please help me, Dr.

    If Dr. need my circuit schematic, please send me an email.

    I really need your help, Dr. I'm looking forward for you're answer. Thank you.



    Sincery,

    Sansan.






  • : MY WEB SITE IS HTTP://BBOOTHE.VR9.COM



    : EMAIL ME WITH ANY QUESTIONS YOU MIGHT HAVE

    :

    :



    I need help desgining a ISA card Sound IO card.

    The sound uses a Crystal 4235 chipset and a small amp. there are 7 outputs.

    I am willing to pa`y for this work.

    Simon


  • Hey i was wundring if you could help me with a remote for my computer? i'm useing a phototransister and a high output led




  • : : MY WEB SITE IS HTTP://BBOOTHE.VR9.COM
    :
    : : EMAIL ME WITH ANY QUESTIONS YOU MIGHT HAVE
    : :
    : :
    : Dear Dr. Boothe,
    : I need some help. I'm building an infrared mouse. I got problem for transmitting infrared pulse with high enough current while maintaining the pulse's DC for 50%. My transmitter system using micro AT89C2051 as controller. It uses +5Vdc power supply. The micro read 6 input buttons and transmit the button status trough serial data transmission. The transmission at 2400 bps, 8 data-bits, 1 stop-bit, no parity. Output port from controller connected with a 555 timer. The timer act like modulator. The NOT gate is placed between port and 555 timer. The gate function is to prevents false transmission of pulse when no data trasmitted from the controller. (The UART of controller maintain the serial output port in logic high when no data is being tranmitted.)
    : I'm using Harris 7555 timer.
    : The 555 timer is designed to transmit 40 kHz square wave pulse with Dc=50%.
    : The output gate connected with pin 4 of 555 timer.
    : pin 2 and 6 tighted together with a 4n7 capasitor to ground. The 1k ohm R and 10k VR connected in series. One side of the R is connected to pin 3, and the other side of VR is connected to pin 2 & pin 6. From calculation the timer can produce a square wave CD=50% with freq bettween 17 kHz to 96 kHz. The transmitter is tuned in 40 kHz.
    : Output pin 3 of timer (+4V when high) is connected with pin GATE of MTP3055E. Pin DRAIN is connected at +9Vdc. Pin SOURCE with two IR LED in series to ground.
    : I use the mosfet to get enough current for driving my IR LED. When measure the output pin 3 from timer using oscilloscope, it supposed to be 50% DC 40 kHz square wave. But I got unreadable freq (it's like osilation) and DC around 60 - 75% with voltage level of +4V.
    : I've check the osciloscope setting, the circuit, the mosfet and replace the timer. But I got the same waveform. The output current from pin Source is around 120 mA. It's quite good.
    : Why I got such waveform? Is there something missing with my circuit? Please help me, Dr.
    : If Dr. need my circuit schematic, please send me an email.
    : I really need your help, Dr. I'm looking forward for you're answer. Thank you.
    :
    : Sincery,
    : Sansan.
    :
    :
    :
    hey i need some help with a IPDS for detection system on my robot that i'm building i useing a high out put led and a phototransister and for the pulses i useing a simple 555timer
    but the phototransister is not picking up any of the trasmision and i don't know why i hope you can help my E-mail address is Danjb15987@excite.com thanks


  • : MY WEB SITE IS HTTP://BBOOTHE.VR9.COM


    : EMAIL ME WITH ANY QUESTIONS YOU MIGHT HAVE
    :
    :
    :

    I am interested in electronics but know virtually nothing about them. I am interested in eventually learning to build a computer (from scratch if possible although that will probably take years to lean). Is it possible to learn from a book? If so, what book?thanx in advance
    a beginner


  • : : MY WEB SITE IS HTTP://BBOOTHE.VR9.COM
    :
    : : EMAIL ME WITH ANY QUESTIONS YOU MIGHT HAVE
    : :
    : :
    : Dear Dr. Boothe,
    : I need some help. I'm building an infrared mouse. I got problem for transmitting infrared pulse with high enough current while maintaining the pulse's DC for 50%. My transmitter system using micro AT89C2051 as controller. It uses +5Vdc power supply. The micro read 6 input buttons and transmit the button status trough serial data transmission. The transmission at 2400 bps, 8 data-bits, 1 stop-bit, no parity. Output port from controller connected with a 555 timer. The timer act like modulator. The NOT gate is placed between port and 555 timer. The gate function is to prevents false transmission of pulse when no data trasmitted from the controller. (The UART of controller maintain the serial output port in logic high when no data is being tranmitted.)
    : I'm using Harris 7555 timer.
    : The 555 timer is designed to transmit 40 kHz square wave pulse with Dc=50%.
    : The output gate connected with pin 4 of 555 timer.
    : pin 2 and 6 tighted together with a 4n7 capasitor to ground. The 1k ohm R and 10k VR connected in series. One side of the R is connected to pin 3, and the other side of VR is connected to pin 2 & pin 6. From calculation the timer can produce a square wave CD=50% with freq bettween 17 kHz to 96 kHz. The transmitter is tuned in 40 kHz.
    : Output pin 3 of timer (+4V when high) is connected with pin GATE of MTP3055E. Pin DRAIN is connected at +9Vdc. Pin SOURCE with two IR LED in series to ground.
    : I use the mosfet to get enough current for driving my IR LED. When measure the output pin 3 from timer using oscilloscope, it supposed to be 50% DC 40 kHz square wave. But I got unreadable freq (it's like osilation) and DC around 60 - 75% with voltage level of +4V.
    : I've check the osciloscope setting, the circuit, the mosfet and replace the timer. But I got the same waveform. The output current from pin Source is around 120 mA. It's quite good.
    : Why I got such waveform? Is there something missing with my circuit? Please help me, Dr.
    : If Dr. need my circuit schematic, please send me an email.
    : I really need your help, Dr. I'm looking forward for you're answer. Thank you.
    :
    : Sincery,
    : Sansan.
    :
    :

    Hi Sansan

    I am woking on Infra red Communication. As since i had seen u r discriptive Information it seems there some conversion chip is to be used. If u can send the circuit schematic i will give the detail working of information about Infra red mouse communication.

    I think there should place a coneversion chip . If u can send circuit schematic i can help u out u r cause.

    Mail circuit schematic to lokesh_ns@rediffmail.com OR lokeshs@myw.ltindia.com
    ALL THE BEST

    Best regards
    Lokesh
    :
    :
    :

  • : : MY WEB SITE IS HTTP://BBOOTHE.VR9.COM


    : : EMAIL ME WITH ANY QUESTIONS YOU MIGHT HAVE
    : :
    : :
    : :
    :
    : I am interested in electronics but know virtually nothing about them. I am interested in eventually learning to build a computer (from scratch if possible although that will probably take years to lean). Is it possible to learn from a book? If so, what book?thanx in advance
    : a beginner
    :
    :
    :


    isbn: 0-13-031486-2


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