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  1. Arouse1973

    How a BJT Transistor works (base current version)

    This is basically what I am saying yes. But you say at low speeds of 1Hz, but you have to consider the rise time and not necessary the period of the square wave. The rising edge will contain lots of harmonics as you know. But I think from all the initial discussions this one and previous we had...
  2. Arouse1973

    How a BJT Transistor works (base current version)

    Hi Claude. Yes please explain your findings later. I think I see what you are trying to explain here and I think we have to be very precise in the terminology we use which is where I think it's gone a bit wrong. What I think you are saying is that the voltage difference between the base and...
  3. Arouse1973

    How a BJT Transistor works (base current version)

    Thanks Claude. I'll look at this a bit later. It's late over here. Cheers Adam
  4. Arouse1973

    How a BJT Transistor works (base current version)

    I'll be interested to see Professor Lutz (Lvw) reply on this one. Adam
  5. Arouse1973

    How a BJT Transistor works (base current version)

    That's because I thought the circuit you sent me was the one to simulate. You didn't mention about it being different. So forget the pulse for a minute, do you agree with the fact you can see a change in Ie which has a very similar slope to Vbe in my first plot. Cheers Adam
  6. Arouse1973

    How a BJT Transistor works (base current version)

    It's simple the circuit you sent me has a reactive component in the CE path, a capacitor across R2. So the easiest thing to do was to insert a 100R in series with the capacitor. Got rid of the spike. Adam The circuit you sent me didn't have R7. Top plot without resistor and bottom plot with...
  7. Arouse1973

    How a BJT Transistor works (base current version)

    Hi Claude It was the schematic you emailed which was very different from your thread schematic for some reason.Your original statement I think was Vbe still increases even though Ie has reached a steady state. It doesn't do this from looking at the plot. Thanks Adam
  8. Arouse1973

    Different answer using inverting op-amp and KCL?

    Because it's inverting. So you have to change the sign to minus. -96/32 = -3 or 96/-32 Adam
  9. Arouse1973

    Different answer using inverting op-amp and KCL?

    Because it's an inverting amplifier so the output will go negative for a positive input. Adam
  10. Arouse1973

    Need help design UV Curing heads

    Some more http://www.ebay.co.uk/bhp/led-pcb
  11. Arouse1973

    Need help design UV Curing heads

    This the sort of thing you need. http://www.ebay.com/itm/3W-365nm-UV-LED-ultraviolet-LED-chip-light-High-Power-bead-with-20mm-pcb-/221264871940 Adam
  12. Arouse1973

    Need help design UV Curing heads

    And I am in Cornwall :) I know a few people who will place the part down for you. It might be more cost effective to have more than one made. Let me look into this for you. Adam
  13. Arouse1973

    Hello, world!

    Hi Kyle and welcome :) Adam
  14. Arouse1973

    Need help design UV Curing heads

    I think it's worth a try. You will probably need a small PCB made and the device assembled correctly to the PCB so any heat can get away as soon as possible. You might be able to find one on a PCB already that you just connect power to. Manufacturers have been combining heat sinks into PCBs for...
  15. Arouse1973

    E2V Argus thermal imaging camera battery/charger help

    No you must not connect a power supply straight to the batteries unless it is current limited. You could damaged the cells. A proper charger is always the best option but if you have some electronics knowledge you could make a constant current charger for 160 mA quite easily. The cells really...
  16. Arouse1973

    Stage Line 500W amp repair project

    Not a chance lol BGA needs special equipment. Adam
  17. Arouse1973

    E2V Argus thermal imaging camera battery/charger help

    No not sure. The third pin might be a temperature sensor for the pack. This was quite common for chargers for Ni-cads. this was used as a charge termination method if the delta V method didn't work. Adam
  18. Arouse1973

    E2V Argus thermal imaging camera battery/charger help

    Ok so you are going to have to take it a part if you can to replace the batteries? Adam
  19. Arouse1973

    E2V Argus thermal imaging camera battery/charger help

    These batteries will last longer. I have tested these batteries and found them to be very good. They replace Alkaline with Lithium technology. Adam https://www.google.co.uk/?gws_rd=ssl#q=lithium+iron+disulfide&tbm=shop
  20. Arouse1973

    Sensorless BLDC motor driven synchronously.....hrmmm...

    Hi ya I think your reasoning is justified for the small motors operating at low currents where the inertia of the motor is greater than the repulsive force given by a incorrectly switched pole. And yes the efficiency is going to be down. When you start to increase the current in the coils to...
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