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  1. Arouse1973

    Help with frequency divider

    Isn't' it interesting the use of Vss and Vdd for CMOS IC's even buy chip manufactures. Voltage source and voltage drain, where the extra d and s come from anyone know? But interesting, an invertor IC labelled as such has the source of one of the transistors connected to the supply. So really...
  2. Arouse1973

    common emitter amp design

    Thanks Kris, yes series feedback I think it's called isn't it? I didn't know that about a.c distortion, I assume your on about clipping and not purity of the waveform in normal use? Thanks Adam
  3. Arouse1973

    Power source help

    Two things, make sure you have 12 Volts from the adaptor. Use a multi meter if you have one. Or you could wire an LED with a 1K resistor and see if it lights up. That won't tell you it's 12 Volts but will indicate some voltage is on the output. The other thing is to check the polarity of the...
  4. Arouse1973

    12V - 36V 30mA Converter using LT1173

    Your 1K will be dissipating 24.7 mA^2 * 1000 = 0.6 W if the resistor has a thermal impedance of 120 deg C (Check your data sheet) per Watt, then the temperature will be 70 deg C + ambient. Adam
  5. Arouse1973

    How a BJT Transistor works (base current version)

    Yep I also use the base current method.
  6. Arouse1973

    Power Source Model 40 Schematic Help

    Got any pictures? Adam
  7. Arouse1973

    Boost converter current calculation

    Oh Kris you do make me laugh PSML :) Love it Adam
  8. Arouse1973

    H-Bridge

    Oh dear! Could have a slight issue with that one.
  9. Arouse1973

    Vacuuming and ESD

    No Probs :)
  10. Arouse1973

    Light measurement

    Many times Adam
  11. Arouse1973

    common emitter amp design

    You have set yourself a gain of 33. This leaves you with a fixed ratio of RC and RE. A good rule of thumb is to choose RE so it drops 1V across it, or better still 10% of the supply voltage. But you won't be able to do this. So if RE is 1K then RC will be 33K. The resistor values should be...
  12. Arouse1973

    Light measurement

    Yeah sorry I should have removed VF1 and labelled VF2 as output. It was a modified circuit from a previous design. Cheers Adam
  13. Arouse1973

    Vacuuming and ESD

    Looks like carbon loaded attachments and the brush on the end should also be carbon impregnated. Looks good to me. Don't forget your wrist strap. Remember an ESD event does not always fail components right away. They can fail over time, many months can pass and then it fails. You say oh well...
  14. Arouse1973

    Vacuuming and ESD

    It's better to have the hoover running also to catch as much of the dust as possible. Do not use a standard compressor without a very good moisture trap, your asking for trouble otherwise. Adam
  15. Arouse1973

    Vacuuming and ESD

    Yes Anti Static spray. Buy the proper stuff but an old trick is clothes washing conditioner which is anti static to help prevent clothing from producing static. Adam
  16. Arouse1973

    Vacuuming and ESD

    The static is produced by the motor spinning around and also the air and pollution molecules whizzing inside the hover and it's tubes can cause static. If the nozzle is plastic or painted metal then no not really. Plastic is not a very good conductor generally so any static build up on the end...
  17. Arouse1973

    Light measurement

    Hi Bob I do agree with you both another op-amp would be better, Sometimes is nice to get on with something you have been working on for a while rather than waiting another day or so for the postman. It's nice to offer alternatives with the components they have. If he had more than one 741 then...
  18. Arouse1973

    laser ablation of PCB resist

    Look forward to seeing the photo's
  19. Arouse1973

    Vacuuming and ESD

    The strap is for you, and you should be using one anyway really. The vac probably has semi conductive hose and nozzle which is why it is more expensive. Adam
  20. Arouse1973

    Help with frequency divider

    What about a CD4059 divide by N counter? Adam
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