I am a senior student in engineering and I am doing my project for my graduation. I am having a problem using one of the chips manufactured my National Semiconductor. I am building a exercise bike for handicapped children which gives output in terms of lights according to the speed they bike. I am almost done but I am stuck with circuit of LM3914. I followed the circuit given in the specs for the 0V to 5V bar graph meter, in there I just changed the value of the R2 to 8.2k with the help of the equation of Ref Out. However, the circuit does not work as I want it to work. Since my input is going to be from 1V to 10V, I am looking to see if each Led lights up to 1V. so the first one will come on at 1V and the second one at 2V and so one until the last led will turn on at 10V. Right now the circuit works only till 4V after that each volt is turning on two Leds instead of one. I am not sure if I am missing anything else or if I am using the wrong circuit. I will really appreciate if any one could give me any advice on this situation. My power supply for the whole circuit is 10V.
Thanks......