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Recent content by tiki

  1. tiki

    DC motor to charge battery

    Hi, I agree with Lewish, that you should regulate/limit the current and voltage (a current source, supplied by a constant voltage source), additionally in dependence of the temperature. Look at the websites of lead acid battery manufacturers for the T/V-characteristics. Keep also in mind, that...
  2. tiki

    Stepper motor drive details

    Hi johnxavier, I'm also involved in a project to build up steering electronics for bipolar stepper motors. 3 channels, 60V, 2,5A, fitting onto a Eurocard (160mmx100mm) for an automotive stepper motor test bench. The same problem: heat. I found out, that the usual H-bridge-ICs do not solve this...
  3. tiki

    Basic Circuit Layout

    I agree with chancy99, also tried it with several layout SWs, like OrCAD (older DOS versions), Protel, PADS, pCAD, EAGLE, Integra (german) and TARGET (german). I found out, that a low budget system cannot satisfy the requirements of a (professional) layout eng. All systems have their problems...
  4. tiki

    Switching low level DC current?

    Hi DRWeig, what about analog switches, if the loop voltage is not too high? look at ADI and MAXIM. There will be no contact problem. tiki
  5. tiki

    Amplify signal level from microvolts to 5Volts

    Hi johnxavier, try this link: http://www.ece.concordia.ca/~dave/project/elec.html, a very "low level" ultrasonic transducer kit. Or: Maxim A0713.pdf (design showcase). For accurate distance measurement you will need high input impedance, high bandwith, low noise amps for amplification...
  6. tiki

    Searching for force transducer.

    Hi mooimooi, I believe, piezo transducers are the ones with the highest possible voltage output signal, if they are followed by a correctly designed charge amplifier, and only for varying forces (inside several seconds, with respect to the leakage currents of the electronics and the transducer...
  7. tiki

    Need to design a Photodiode amplifier circuit

    Hi Ejaz, take a look also at the BurrBrown (now TI) application notes, they describe photodiode solutions very clear, also with respect to noise problems. For TIAs with high gain look for OPA with very low bias current (significantly lower than dark current of the Photodiode) and gain unity...
  8. tiki

    buck boost converter

    All significant dcdc-ic manufacturers publish circuits for this "problem": SEPIC-circuits are one of the easiest solutions. Look at www.maxim-ic.com, they are specialists for those ICs. If the output voltage must be very stable (better than 1%), you should combine a reference and a low...
  9. tiki

    simple fast pulser

    Hi ojim, SN74AHCT1G02 (OR Gate) has typ. 2.4ns to 4.5ns switching times from input to output, but with the absence of heavy capacitive loads. Rise/fall times of the outputs are not defined, but should be inside these margins, input tr/tf must be inside 100ns. ACT Logic has output transition...
  10. tiki

    Xenon strobe sensitive to ambient light?

    Hi rads, sometimes some manufacturers use plastic encapsulating material for their components, which seem to be opaque, because they are black. But IR may be let through, see packagings of consumer IR-transmitters/receivers. First, try to wrap a thick cloth around the electronics (not the tube...
  11. tiki

    digital feedback controlled amplifiers

    Hi electron, this book, written by BB, seems to be interesting. Do you have any more information about it (title, year of publishing)? I know the BB linear applications handbook (1994) only. Thanks! tiki
  12. tiki

    digital feedback controlled amplifiers

    Hi lukeyd, look at http://www.ibtk.de/guides/prodguid.htm. Some years ago I built such amps. This one had a digitally controlled gain (feedback variaton) of 1.000 to 15.000, others are possible. I can send you an schematic by email, if you want. Just now I develop another precision amp with a...
  13. tiki

    axial flux

    Hello, look at these links: http://www.evt.ele.tue.nl/epe/onderzoek/projecten/Perm_magnet.asp http://www.wempec.org/users/lipo/1998pub/luo2Ias98.pdf http://helium.ee.tut.fi/p_research_we_files/weg_articles/ICEM2000.pdf http://sant.bradley.edu/ienews/99_4/Technology.htm...
  14. tiki

    thermocouple aray, thermal conductivity of snow

    Hi nbucska, if you measure the thermocouple induced voltage with a relatively high impedance, the impedance of the wires will be neglible, and it will not self-heat. But the small voltages may require a preamplifier with very good dc-performance (chopper). tiki
  15. tiki

    thermocouple aray, thermal conductivity of snow

    Hi clouddancer, If you want to know the surface temperature of the snow, a pyrometer would do the best, fast and reliable. You need to know the radiation coefficient of snow/ice. Wood, especially light wood like Balsa, has <0.2W/(m*K), glass has 0.6-0.9W/(m*K). Maybe, carbon fibre has a low...

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