Search results

Search Forums New Posts
  1. Arouse1973

    4-20mA using XTR111

    Very neat trick Kris, although I think your formula works out that it has gain, how does this work? Cheers Adam
  2. Arouse1973

    scr driver circuit for battery charger

    Couldn't you bypass the SCRs and just use a 40 Volt PSU instead? Just a thought. Adam
  3. Arouse1973

    Adjustable voltage and current device.

    I was just going to suggest a PSU but you mentioned a battery as your power source. Adam
  4. Arouse1973

    Light measurement

    Increasing the feedback resistor will do this. Adam
  5. Arouse1973

    4-20mA using XTR111

    Yeah sorry I missed that bit duh! Apologies Adam
  6. Arouse1973

    Help to make a switch from an led and sensor pleasr

    Its what we call a break beam sensor. It has its own plastic moulding. You will have to tell us the voltage level that camera can take first. Is it active low or high? Adam
  7. Arouse1973

    4-20mA using XTR111

    You normally use a 250 Ohm resistor to give you 1 to 5 volts. Why do uou want 0.4 volts? Adam
  8. Arouse1973

    Is this layout good for a DC-DC converter?

    Ok dont look too bad. But I would move the feedback trace to the other side of the PCB or move it well away from the switching side of the inductor. You have done better than some I have seen from some engineers. You have kept the important components close together which is good. I always like...
  9. Arouse1973

    Why does longer probe cable reduces bandwidth

    If its distributed capacitance then within reason how does this matter versus length? Adam
  10. Arouse1973

    Fuel Gauge converted to Volt Meter

    Cant see how that will work. Your input is what is changing its not constant. Also your resistors are shorted. Adam
  11. Arouse1973

    Fuel Gauge converted to Volt Meter

    Ok so it might have internal supply. Connect say 50R to the sensor input and 0V.Measure the voltage then do the same with the resistor connected to 12V, then repeat with half the value of resistance, this will tell you if its a current source . We need to quantify the voltages that make the unit...
  12. Arouse1973

    Probe and impedance

    The scope probe is made up of usually these components: All of these will vary dependant on the probe. I am talking about the standard scope probe most people use. 1) Tip capacitance of say 15pf 2) Capacitor adjustment for waveform purity. 3) 9 M Ohm resistor near probe tip. 4)...
  13. Arouse1973

    Fuel Gauge converted to Volt Meter

    Thinking about it now. To maintain accurate readings with battery level variations they probably have a constant current output from the cluster. does the cluster have it's own dedicated power wire for a sender unit? Adam
  14. Arouse1973

    Fuel Gauge converted to Volt Meter

    This is what I mean, the bottom resistors are fixed and represent the input resistance of the cluster, but there will be only one in the real unit. I have shown it like this so we can see the difference between them. I just chose 100R of the top of my head it will most likely be different. For...
  15. Arouse1973

    Fuel Gauge converted to Volt Meter

    Me too, my misses says I run the marathon some nights in bed, you wouldn't think so looking at me :) Adam
  16. Arouse1973

    Fuel Gauge converted to Volt Meter

    Ok good. The cluster manufacture must know how to convert this in their equipment. So they must have a resistor inside that convert the current going through the sensor resistances to a voltage that they can measure. Are you able to reproduce these resistance with a POT and measure the voltage...
  17. Arouse1973

    Fuel Gauge converted to Volt Meter

    I am glad I am not the only one that does that. God Bob even after all these years you still have the enthusiasm. That's nice. Adam
  18. Arouse1973

    Fuel Gauge converted to Volt Meter

    Just thinking about this. The new cluster has an input for the fuel gage right? I know you did the tests with a 5 Ohm resistor but why did you think such a low value was needed. I struggle to understand this as in normal operation you would have a considerable current. Which would be wasting...
  19. Arouse1973

    Is this layout good for a DC-DC converter?

    Duh, I thought that was a cap. Yeah sorry. Adam.
  20. Arouse1973

    Is this layout good for a DC-DC converter?

    I meant I cant see L2 on the PCB. Adam
Top