resistor value,

I wish to replace the trimpot in the Adjustable 1.3-22V Regulated Power Supply with a fixed value resistor to give me 5v DC output. The input voltage is 12v DC. what value resistor
should I use to replace the trimpot with.
Ian

Wouldnt it be far easier to use an lm7805 fixed 1 amp regulator as opposed to replacing resistors which are going to possibly fail at some point Also how many extra components would you need Simply modify the circuit taking the center leg straight to ground on the lm7805, One input, One output decoupled with a 1uf tantulum cap rated at 16volt working, Input positive feed tied to diode 1n4001 so that you have reverse polarity protection Must be easier and far more sensible than what you are trying to do although not incorrect just better economics and stability

Resistors change value as they get hot or warm so output voltage will also change with this

Which is better do you think?

If you must do this then quick search on the net will reveal online calculator Here is the address

http://www.electronics-lab.com/articles/LM317/

To calculate the values of adjusting resistors use this program (see attach).

The answer is 330 ohms.

I think this is quite strange if you think about this Why can this person not look this up himself Is it me or does no one know how to use a search engine I suppose at some point some 20 years ago when the net was first introduced I didnt know to much iether but 20 years on and people are still asking questions here which if you think hard about this They can post comments upload files but for some obscure reason cant perform a search Ok id say fine if they couldnt read but they can otherwise they wouldnt be posting question Id say fine if they were blind Yes id understand this too although microsoft have brought out SAPI text to speach and visa versa so why i ask is this such a problem

Forgive my ignorance in this case I appologise for not being able to comprehend this in which case rightfully please educate me so that I do understand this

Thankyou

Mark

yes, it seems the power of the search engine has been negated by being lazy? forgive the term.

floy