Hey all, i was wondering the diffrence between carbon film and metal film resistors. And if one is better than the other.
Metal Film = Lower % of value accuracy, ie, a 1Mohm 2 % resister could have a value between 1M +/- 20K Carbon File = Higher % of value accuracy, ie, 1Mohm 10 % resister could have a value between 1M +/- 100K Metal Film cost more. if just doing a i/o pin pull up, Carbon is fine, but if building a 555 timer circuit, and need precise timing, then metal file would be the way to go.
If does depend on what you are going to use them for. However for about 95% of things carbon film resistors are going to be good enough (common tollerance is 5% anyway and 2% are not that much more expensive). Unless you need high precision (which for most things is unlikely, common metal film tollerance is 2 to 1% ) or a circuit that requires low noise (which for decent audio circuits you would). As for a 555 timer circuit, you would be better off with a 4060 IC with a low frequency ceramic oscilator...
or use a microcontroller (avr/pic, etc) with programmable pwm a 4060/w an oscillator would be nice if you didn't need to adjust the frequency via a variable resister., but yes, if you needed a perfect "100Khz" signal, i would not use a 555 timer, i would build something more robust, and divide it down. , ie, 1Mhz / 10
Yes... just dont get some old ones from 1960 that are the dark brown, and the size of a cigarette butt.
LOL i dont think they are from 1960. I just ordered the ones i need from mouser electronics. Thanks everyone for the help!!!! This forum is awesome!!! Scott
