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I saw on this group .... somebody wanted to know the
difference between the LM 3914 / 3915 / 3916 ?? I
accidentally erased that original email so I can't
recall what the original question was!!

Anyways.....

You're right ... that schematically, the LM39XX chip
ARE the same. The ONLY difference is the CALIBRATION.
The 3914 is a linear-ly calibrated device. It's
output changes one-per-volt (or per-amp or per ohm or
whatever)

The 3915 is LOGRITHMILLY (maybe someone could correct
my spelling!) CALIBRATED.

The 3916 is calibrated by dB's (like in audio/VU
metering etc). It's output changes
one-per-(audio)dB.

Now I'm NOT sure what the difference is between
LOGRITHMILLY (again, spelling) and DB calibrated is.
I've always thought that dB's WERE log.

I just know that because once upon a time a project
required me to read the spec sheets and that is what
it said. So I thought I'd pass it on.

Hope that helps!!

Curtis

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--- Curtis Sakima <electronichobbyist@y...> wrote:

I saw on this group .... somebody wanted to know the
difference between the LM 3914 / 3915 / 3916 ?? I
accidentally erased that original email so I can't
recall what the original question was!!

[snip]

You're right ... that schematically, the LM39XX chip
ARE the same. The ONLY difference is the CALIBRATION.
The 3914 is a linear-ly calibrated device. It's
output changes one-per-volt (or per-amp or per ohm or
whatever)

[snip]

The 3916 is calibrated by dB's (like in audio/VU
metering etc). It's output changes
one-per-(audio)dB.

Curtis, that was me asking. Basically I was asking if
there was any benefit of one over the other. The original plan
was to drive a few (10-15) LEDs as a throttle position indicator by
using a linear slide pot to change the reference voltage. A few here
suggested the LM3916. In looking for the chip to purchase, it was
discontinued, but there were references to the 3914, and 3915 chips.
Now with your explanation, it seems the 3914, would be the chip to
use since I want to measure voltage?

Brian

Oh, I see what you're doing! :)

Yeah, I think the 3914 (in my opinion anyways) would
probably be your best bet. However, it's not "because
you want to measure voltage". It's 'cause of the
CALIBRATION.

Maybe an example would be in order.

If you were to use a 3914, engine idle would be, for
example, one LED being on. Move the throttle up, let's
say, a 1/4 inch ... and another LED pops on.

Another 1/4 inch ... another LED. Another 1/4 inch
... another LED. And so on. Until at full throttle,
all the LED's are on.

With the 3915 / 3916, the circuit would "still work".
In a sense that the "more throttle = more LED's".
It's just that the number of LED's per 1/4 inch would
not remain the same as the pot slid up. From zero to
1/4 ... from 1/4 to 1/2 ... from 1/2 to 3/4 ... it
would take more and more pot sliding to get "one more"
LED to switch on.

Curtis

--- battmain@... wrote:

Curtis, that was me asking. Basically I was asking

if there was any benefit of one over the other. The
original plan was to drive a few (10-15) LEDs as a
throttle position indicator by using a linear slide
pot to change the reference voltage.

Now with your explanation, it seems the 3914, would

be the chip to use since I want to measure voltage?


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Find a job, post your resume.

--- In Electronics_101@y..., Curtis Sakima <electronichobbyist@y...>
wrote:
[snip]

Yeah, I think the 3914 (in my opinion anyways) would
probably be your best bet. However, it's not "because
you want to measure voltage". It's 'cause of the
CALIBRATION.

Ok, I'm going to try the LM3914, and draw up a schematic. I'll be
back for critique when I get it drawn up. :)

Thanks,
Brian