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  1. Hello, The transistor will detect if there is a current flow through the LED right? so if there is a current, then the +5V will be the output at the transistor right? Thanks...
  2. Thanks again Audioguru, I have Email you for another question. I still remember you said
  3. The data sheet can be found with the link bellow. http://www.datasheetcatalog.com/datasheets_pdf/L/M/3/9/LM3915.shtml bassiclly i understand the LM3915 basic operation about what is the LM3915 does. What i dont understand is, how does the voltage/current flowing out to the LM3915's pin as shown in the diagram bellow..
  4. i have this idea. Can i connect the signal to a ADC converter? let say i connect it to a PIC's ADC pin. we run the program to check the level of the converted signal.
  5. how if i operate the LM3915 in bar mode? is there is any method else then you have mention above?
  6. how about comparator? we can use comparator to compare 2 current right? comparator such as LM393 has a very low bias current. http://www.onsemi.com/pub/Collateral/LM393-D.PDF if logic not possible,do you have any suggestion?
  7. CMOS Logic is new to me. I haven't have any experiance with it. Now i'm reading about it. okey. now the question arise, which Cmos logic to use? i never uses any before. What is the model number?
  8. Hello Again. I come up with a new question. I'm planing to connect the 14th or13th (or 12th) LED to trigger the interrupt on my PIC16F84. I think that we can generate needed voltage for interrupt by connecting the signal form an LED to an logic gate. Here i use an AND
  9. Hello, The circuit work very well using the Average detector. figure bellow show how i supply my Rhi. When i change the R1 to smaller value (20k), the first 2 LED will lights. When i use 220k, the first 5th LED wont light up (dot mode). It starting on the 6th LED. Playing with the R1 value can give me a good result without knowing what is the true Voltage or current for the Rhi. Any comment about the diagram above? how i can supply my Rhi with 1.6v? btw, the capacitor seem does not affect The Rhi? am i right? How do i make the LED to discharged slowlly? i meant, the LED suppose to light up quickly(sensitive) but light off slowlly? increase the C8 value will do the job?
  10. Hello, i cannot figure out how the average detector work. It seem kind of half wave rectifier to me? well i'll try this out today. What value of the Rhi should I set? 2.5v?
  11. every ( inverted signal)circuit need dual supply? is this what do you mean? do you mean integrator Op-amp? hemm this mean i need another circuit for integrator?
  12. Hello, Can i use any average detector instead of the one in data sheet? I have some LM358. can i use them to build average detector for my LM3915?
  13. you mean. i dont need transistor Q1,Q2 and Q3? so the output signal from pin7 should connect to my average detector? the rectified signal should connect to signal input on pin 5 of LM3915 right? then i'll update you soon. thankx
  14. my bad.. i dint check the LM and LF datasheet :'( ok thanks for the advice. btw can i just replace your peak detector shown in the figure bellow(link) with the average detector? or do have some suggestion?
  15. hello again, i cannot see the dual supply for the data sheet. Where am i suppose to connect the negative supply? How to change the led lights so that it lights not too fast and light off not to fast also?
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