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  1. OLIVE2222

    DC power supply

    Hi, I mean avoiding to have a voltage setted when powering the supply up whatever the potentiometer position will be. The aim is to avoid burning things because of over voltage. Olivier
  2. OLIVE2222

    DC power supply

    Hi, maybe a system ensuring that the suply start at 0V at power up can be a nice feature. Olivier
  3. OLIVE2222

    Wanted: wanted - a copy of certain articles from wireless world Magazine

    Hi, here you are madevan: http://www.vintagecomputers.btinternet.co.uk/comp80/ Olivier
  4. OLIVE2222

    Can I use 2 x transformers?

    Hi Paul, If it's match your current needs you can made a symmetrical 24V supply with only one of your transformers. See the idea here under: http://freecircuitdiagram.com/2008/08/14/regulated-15-15-volts-symmetric-power-supply-from-12-volt-transformer/ You need to leave the center tap...
  5. OLIVE2222

    Can anyone name this connector?

    Hi, looks to be AMP Micro Match: http://be.mouser.com/Search/Refine.aspx?Keyword=micro+amp+match&OrgTerm=amp+micro+match&NewSearch=1 Olivier
  6. OLIVE2222

    Basic RF relay switch help wanted

    Hi Toddie, There is a big difference between a wireless door bell and a key finder! On the door bell there is a push button, mean that the emitter don't draw any current when not used. On the key finder the receiver is always supplied mean that after few days you run out of battery. So as...
  7. OLIVE2222

    Basic RF relay switch help wanted

    Hi Toddie, Welcome to this forum! technically you can use such modules to made a key finder. The range will depend on many factors, however it' easy to try, the main caveat is the battery life. The receiver is 5V powered not close from standard batteries voltages. Such project can more...
  8. OLIVE2222

    8051 internal adc

    According to the uC data sheet here under (page 87) "The channel select bit in ADCF register define which ADC channel/port1 pin will be used as ADCIN. The remaining ADC channels/port1 pins can be used as general purpose I/O" http://www.keil.com/dd/docs/datashts/atmel/t89c51ac2.pdf You you...
  9. OLIVE2222

    Project: Vibration Measuring Device

    Damien, The PICAXE is for more oriented for Tiny projects. I recommand Arduino if you want to build a mockup with an LCD and a (mini) SD card. They are huge amount of Arduino (and compatible) boards. You can also go for Arduino hardware platform and use the free AVR studio as C IDE. To be noted...
  10. OLIVE2222

    8051 internal adc

    Hi, The 8051 don't have any ADC. You maybe use an improved µC based on 8051 core. Please specify the exact IC reference. Olivier
  11. OLIVE2222

    Project: Vibration Measuring Device

    Hi Damien, The LIS3L02AL is declared obsolete by ST (as many analog accelerometer). You can have a look on mouser or digikey for other parts. Basicaly an analog accelerometer can be connected with minor adaptation to a voltmeter module for each axis. More practical setup will involved an analog...
  12. OLIVE2222

    how to convert analog output voltage (3V to 5V and 4.6V to 5V) to (0V to 5V)

    Hi maxima_diesel, To map arbitrary signal range to something like 0-5V you can use a normalizing amplifier. The procedure is explained on page 16-17 of the following document: http://www.ece.ucsb.edu/courses/ECE002/2B_W11Shynk/PracticalAnalogDesign.pdf Both the offset and the gain can...
  13. OLIVE2222

    atx smps help

    Hi milan3210, The voltages outputs must be within +/- 5% tolerances see, page10: http://formfactors.org/developer%5Cspecs%5CATX12V_1_3dg.pdf However it' s will depend on the measurement (load) conditions and indeed you need a calibrated instrument. The displayed values seems OK to me. Olivier
  14. OLIVE2222

    LED down count

    Hi Viad, I use 74HC14 based debouncing circuit many often but for a one "channel" application a 555 based circuit will be OK. For the records: http://www.edn.com/contents/images/196470.pdf Olivier
  15. OLIVE2222

    K8055 Interface Board & Breadboard

    Hi Chris, This board have a ULN2803 as output driver: http://www.velleman.eu/downloads/0/illustrated/illustrated_assembly_manual_k8055_fr_rev3.pdf So you have to connect the led as illustrated on page 19 by providing a positive supply and, imperatively, adding a resistor to the led. Olivier
  16. OLIVE2222

    LED down count

    Hi Viad, Yes, with a relay you should use a debouncing circuit. Olivier
  17. OLIVE2222

    Cut heatsink tab off 7805

    Yes the TO92 package can handle the 0.3W, but adding a zener diode at the regulator input can give a bit more headroom (without being too bulky). Olivier
  18. OLIVE2222

    Mt8870 dtmf decoder circuit

    yes I have worked with in the frame of a phone call locker. Olivier
  19. OLIVE2222

    Mt8870 dtmf decoder circuit

    Hi atollp and welcome to this forum ! The 8870 is an industry standard component for tone decoding. It' a proven and easy to work with part. Olivier
  20. OLIVE2222

    Cut heatsink tab off 7805

    Hi Kickit2, You can cut the tab off. Doing the thermal dissipation calculation with this tool, http://www.daycounter.com/Calculators/Heat-Sink-Temperature-Calculator.phtml for the TO263 package (close to your cutted TO220) http://www.ti.com/lit/ds/symlink/ua7805.pdf give less then 40°C of...
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