1/8th Watt Resistors OK?

Parts Questions
1

I only see one mention of them in the Deutsch forum. Around how much are the average i/o pins looking for with stuff like this (pullups on the DINs and LED current limiters)?

Just being safe. :wink:

George

2

1/8 watt is fine if they are pullup resistors.

Anyone disagree? letā€™s seeā€¦ .125 is 1/8 watt soā€¦

I=V/R

5V / 10000 = .0005

^volts ^resistance ^current

Each resistor lets through .5mA (amirite?)

P=IV

.005 * 5 = .025

^I      ^V  ^P (watts)

Each resistor dissapates .025 watts, 5 times less than the max of a 1/8th watt

Yep. I hope.

3

Thanks!

So Iā€™m fine on 10k pullups then.

What does the average 3 or 5mm ā€œstandard powerā€ LED pull?

(sounding lazy as s*** right now)

George

Iā€™ll look around a bit anyway. :slight_smile:

4

Hey again,

Around the middle of this page:

http://www.opamp-electronics.com/tutorials/special_purpose_diodes_3_03_10.htm

thereā€™s a 6V LED circuit with a 220ohm, and he calculates it to 88mW and says the 1/8W is enough, so I guess Iā€™ll go with those.

Take Care,

George  (building a giant Digikey order and a drill press and a MIDIBox simultaneously ā€¦perhaps)