Hello everybody.I have a question about the lm3914. I want to make a circuit that I can put a voltage in, and get a digital out,a simple a/d converter.The lm3914 works great because I can put a varying voltage in,and either get a bargraph output or a single led output all from just changing the mode on the chip.The problem is the 3419 gives a LOW(ground)(0v) output.What I want is the single LED output(not bargraph) and have the ouput be a HI(Positive voltage).I know that I can convert the output signal with extra components,but I am trying to keep it as simple as possible. Is there another a\d converter chip I can use that has a single input like the lm3914,and will meet the output characteristics as stated above.Thanks for the help...... :roll:........ :idea:

 

I don't know of any, but you could invert the input (so instead of going from low to high, it goes from high to low), this will make the outputs go from high to low - starting with the highest one. I don't know if the LM3914 outputs are open collector or not, but if they are you would need pull-ups on the outputs.

 

Thanks for the quick reply.I guess it is a different time of day over the pond...... .....Anyway,the output is low(0v)(ground) on the 3914.I managed to use a pnp transistor to invert the output.Would a good old 7404 work as well.Thanks again....... :shock: