Recent content by TechSpec

  1. T

    GPS timebase signal

    Well, i consider GPS to be a harder task, but if we think that equipments should work anywhere in the world, i prefer GPS instead of radioclocks. Radioclocks seem to have different frequencies and different range, and even different protocols. And what i have found in my work and in generally...
  2. T

    GPS timebase signal

    GPS modules produce a very accurate 1 second timebase signal, rms differency of about 20nS. How do you suggest of using that to split it into a 1000 pieces = 1000Hz = 1000ms ? My idea is to make a generator with a quartz chrystal and drive it in to a counter module, carefully selected divide...
  3. T

    Phototransistor vs photodiode ?

    Actually, i skipped OP-circuits because some manufacturers offer ready made, highly developed amplifiers in one chip, like for example Atmel, those have built-in interference filter circuits and such as AGC(auto gain control) and ATC (auto strong signal adaptation) to be a complete amp unit, its...
  4. T

    Phototransistor vs photodiode ?

    HI all, i'm currently working with IR sensor diodes, and trying to find a proper device for my project, however i havent found a good unit which fills my needs. Now that i have extended my search to phototransistors, i wonder are they compatible with photodiodes? Im using Atmel's...
  5. T

    IR-light focusing and collimation

    I just red that a digital camera is a very sensitive to IR, but this is blocked away with internal filtering. If its not filtered, IR can cause unsharp images as it has a different focal point on lenses than visual light : http://www.naturfotograf.com/UV_IR_rev07.html On that link above...
  6. T

    IR-light focusing and collimation

    Visible led should have exactly the same radiation pattern and the housing to get the equal results between these two diodes. And because the IR has a different focal point than a visual light, the result would not be the same. TechSpec
  7. T

    IR-light focusing and collimation

    Hi, first of all, i made a simple illustrating picture what i was thinking. I put a file into here:Link The purpose is not just focus the beam into a spot, but focus it to an area of a size of that lens, about 30mm. Thatway the beam would be similar size on all of its lenght. That photodiode...
  8. T

    IR-light focusing and collimation

    HI, im thinking of how can i focus and make a home made collimation to an IR beam. I have a lens and an IR-led mounted to a center of a focal point. But its hard to collimate the beam properly without visual sight to IR. B/w-video cams are usually lit with a series of IR leds to have enough...
  9. T

    EMI and ESD on helicopters

    discharge i have seen some pictures where a helicopter has a discharging "wire" hanging from a bottom of its shell. Those pictures were taken in a helicopter landing area on a floating oil pumping station somewhere. Those discharging wires or plates are best solution as you can control the...
  10. T

    Air pressure and height

    True, but... That is the formula i found too, but it solves the pressure, not the height. And i have no method of opening that formula to solve the height with a given pressure.. so i made this really really really stupid method of doing it and it is highly simplified, but you can see the...
  11. T

    Can you 'fool' a proximity sensor?

    different type of detection Berkeman, i agree, AC loops wont work with earths magnetic field. However, there are different types of sensors available like Honeywell. They have sensors to detect vehicles with a different principle of detection. They are based on earths magnetic field variations...
  12. T

    Simple digital delay line

    RC delay i agree with xez, circuit should look like this. im not sure which capacitors are the most suitable for the circuit, as they all tend to have variations over temperature. But with a little search i found Murata ceramic capacitor type C0G which is extremely stabile over temperature...
  13. T

    EMI and ESD on helicopters

    Hi What kind of problems ESD can cause to a helicopter? Blades are usually made from a carbonfibre and they can cause electrostatic charge into a helicopter structure. Is there any method to prevent that to happen? If that charging occurs, what happens when heli is landing, will it discharge...
  14. T

    Air pressure and height

    Air pressure and height.... Ok, i have a hard time with the air pressure. I should do a calculation with the pressure and determine the height. I have a pressure sensor which i use for pitot-tube sensing and i have a static sensor of the same kind to measure static reference pressure. I can...
  15. T

    Can you 'fool' a proximity sensor?

    not easily done. Probably not, sensors which are based on earths magnetic field changes like traffic sensors, are hard to pass, anything that affects into a field may trigger the sensor. Even if trying to jam the field with an another field would be very difficult as you dont know the reference...
Top