How LM3914 can be set up to work with a symmetrical input given these parameters?

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Joined Mar 13, 2009
I came across with this riddle, Can LM3914 which is a bar led driver be used as an exclamation point and alarm flasher when there is over voltage?.

The requirement which I have is that an input going from -5V to +5V, the chip has to indicate over range for both. i.e lets say if the input is -6V, the bar indicator has to begin with the "center at zero" and go up to -V (given that half of the range from +V to 0 remain all leds off) and to flash as means to indicate over range. This same procedure to be applied for i.e +6V turning on the leds from 0 to +V and flashing to indicate again over range (given the other half from 0 to -V to be turned off).

Is it possible to arrange that led driver to work as the desired requirement? There are no any other caveats, so op amps and level shifters if required can be used.

I tried to inspect in the datasheet from that specific chip and I found only the recommended set ups for exclamation point and alarm seen below.

Regarding the part where it is pictured if that given the resistors value if it can be used for 5V too I think it would be okay as the base current for the transistor that I intend to use 2N3904 the max collector current is 200 mA and with 1 kOhm seems good to go. Although any clarification would be greatly appreciated as well.


Joined Oct 2, 2009
It would be too much trouble to convert an LM3914 to be centre zero with exclamation point display.
Use a microcontroller chip instead.