Search results

Search Forums New Posts
  1. R

    What's the best way to learn any programming

    Hi I think C is a good language to learn. I would start with a good book and start off with console as the output i.e. printing your name. Learning all the commands such as if-else, for loops, arrays, pointers, case statements, structures etc. This would give you a good grounding. I would get a...
  2. R

    Square wave to DC level

    Hi Harald, Many thanks for the schematic and waveform simulations. This is basically working as required i.e. when there is no pulse the capacitor charges via R2 and once it crosses the voltage set by R3/R4 it will be a high at the output of U1. Otherwise the output stays low because the...
  3. R

    Square wave to DC level

    Thanks for the info. Much appreciated. I wanted the cheapest way to do this as cost might be an issue also PCB space is a problem. Hence the 7V signal through a resistive voltage divider, then RC low pass filter and into the PIC ADC or PIC comparator input.
  4. R

    Square wave to DC level

    Hi, Yes it is a 7V square wave signal, 50-50 mark to space and 4kHz. I need to reduce this to around 3V (for A/D or comparator of PIC micro) - I was thinking potential divider, then a RC filter (as explained above). Would I need a voltage follower after the RC filter? It is feedback from a...
  5. R

    Square wave to DC level

    The frequency will stay the same at 4KHz. The duty cycle is 50% on off. I will have a loo at the peak detector too. Thanks for the help.
  6. R

    Square wave to DC level

    Thanks will have a read. Its a square wave input.
  7. R

    Square wave to DC level

    Hi all I have a 0 to 7V square wave signal. Frequency is 4KHz. I want to convert this into an 0 to 3V signal to be read into PIC A/D or Comparator. My initial solution was to use a voltage divider to reduce to 3V, This still leaves me with a 3V square wave. Can i use a low pass filter then to a...
  8. R

    Opamp to pic a/d

    Thanks for correcting me Bob. Thanks for your help
  9. R

    Opamp to pic a/d

    Thanks. Is he reason i dont have to worry because the op amp has low output impedance?
  10. R

    Opamp to pic a/d

    Yes i was going to divide using voltage divider then feed into a voltage follower. If i choose my impedance (voltage divider resistors in parallel) to be less than 10K. Then would that seem reasonable?
  11. R

    Opamp to pic a/d

    Thanks for the replies. I have just learned that the signal is DC only after doing some work. So my question is the bedt rechniques to bring 7V down to a readable input of the PIC A/D? 1. Is it ok to use a potential divider and the centre pin of the resistors straight to the PIC A/D? 2. The...
  12. R

    Opamp to pic a/d

    Oh thanks for this. I thoughtbthst you cant exceed the levels of the pic by +/-0.3V of Vdd and Vss. So you cant go to 5.3V or -0.3V
  13. R

    Opamp to pic a/d

    Adder circuit. I was thinking in the lines of diode clipper circuit fed into the A/D so the negative part of the signal is nit tajen into account. Does that sound reasonable?
  14. R

    Opamp to pic a/d

    Hi Thanks for your reply. I was going to use a 5V single sided op amp. The gain i need is roughly 100. I am now confused when you mention resistor attenuator? If i did have a negative signal for example (say -0.7 to 1V), how could i use it with the PIC? What techniwue voukd i use to bring the...
  15. R

    Opamp to pic a/d

    Hi I just wanted some advice. I have a signal of 25mV. This i want to feed to a PIC A/D pin. However i eant to amplify this to say 2.5V. Would it be ok for me to use a non inverting opamp and suitable resistors to provide the gain/amplification? Do i need any care in selecting the resistor...
  16. R

    Clamping circuit for PIC A/D

    Please could you explain.
  17. R

    Clamping circuit for PIC A/D

    Thanks for your help. Could you show me a circuit diagram please. My idea was a zener to clamp the voltage say to 3V9 then use a GET as source follower. But this is info that I am not sure how to implement 100%. I' A bit confused you mention high impedance Load to source. If the PIC had...
  18. R

    Clamping circuit for PIC A/D

    Thanks. Is my zener method not good
  19. R

    Clamping circuit for PIC A/D

    Yes it is just to see if the piece is working bit it delivers 60V pk to pk..but I am not sure on your circuitvto reduce this to 0 to 5v.
  20. R

    Clamping circuit for PIC A/D

    Sorry frequency is 4Khz it is from the feedback pin of a piezo. I thought the easiest option was to clamp this using a zener but was unsure what would happen to the A/D input of the PIC. The signal detects if the piezo is working or not.
Top