Voltage lost difference?

[alparent]

Is there a difference in the voltage lost (is that what the Vf is?) between using a 1N5817, 1N5818 or 1N5819 as a polarity safety device?

[PRR]

Datasheet

[alparent]

I did look at the datasheet.....that's why I'm asking if the Vf is what I should be looking at?

[Mark Hammer]

Bottom of page 2, you'll see that the 5817, 18, and 19, will lose you .32, .33, and .34v, on average.  Of course, that's only 10mv, which could easily be the difference between any two specimens of a 5817.  So, if one was planning for a commercial product, such average ratings would provide some guidance as to the specs for the rest of the design.  On a one-off basis, wit 9v batery-operated circuits such as what you or I do, there is really no predictable impact.  Figure on about 1/3V, and leave it at that.

[alparent]

Sorry for that stupid reply  

I didn't see that image when I looked a the reply from work  

For some reason I don't see some images when I'm at work?

Thanks for the reply PRR and Mark  

So if I look at the other differences in the datasheet. If I wanted to use them as a simple in series polarity protection for 9v effects. The 1N5817 (.05 cents) should do the job? No need to go to 1N5819 (more Vf but only .03 cents.) Right? Or will they actually be no real difference in the Vf and I should go with the 1N5819?

What's do you guys think?

[PRR]

> .05 cents .... .03 cents
What's do you guys think?

You are asking if you can save TWO CENTS?

I think you are OVER-thinking.

Throw in a 1n400x. Can you even notice the drop in your particular circuit?

[alparent]

I don't think I'm over-thinking. I'm trying to learn!
I don't want to just build effects by numbers......I like to think and ask questions.

I'm not trying in to save 2 cents. I'm asking if there will be any actual difference in the actual power drainage of the battery if I use one or the other.

I'm asking 'cause I value the opinion of knowledgeable people.

I know I could throw in any 1N400? (or I could go without any polarity protection for that matter!)
But If I can educate myself and build a better effect and make it consume less of my batteries power......why shouldn't I?

[darron]

the diode isn't actually using that small voltage, it is just not allowing it to pass. so power 'drained' isn't really changed the way that it sounds like you may expect. in theory giving your circuit that fraction extra of a volt with a 1N5819 might make it consume a little more as it is fed a higher voltage.


in most cases it shouldn't make an audible difference. for example, feeding an opamp 0.6v or so extra will probably have the exact same sound. feeding transistors in a fuzz face or similar will raise the gain a tiny, tiny bit.



sound right to everyone?

[alparent]

HAAAAAAAAAA!!!!!!!!

I get it now!

Thats a perfect example of what I was saying............I'm here to learn........and I've learned.

Thanks a lot Darron.