Dual Voltage Monitor Project

I wanted a module that would display the outputs of my envelope generators and designed this module around the LM3914 dot/bar display driver.  I included multiples so I could fan out to multiple modules.  The LEDs are calibrated on the half volt.  (e.g. +1 is on for 0.5 to 1.5 volts). [Update - 16 years later I built a second module and have a much better camera so photos are updated!]


I made this on a prototype board that directly mounts all the LEDs. It is hard to wire as I mount the LEDs first to get the spacing correct and then wire around them.



It is a pretty simple design. The LM3914 handles the lower 10 LEDs and a separate comparator handles the +5V LEDs. Three trimmers set the adjustments.

DJB-005 FrontPanelExpress design file

DJB-005 schematic