Sunday, March 10, 2013

INSTRUMENTATION PROJECT PART SEVEN: ASSEMBLING THE PANEL

My original plan was to have four digital meter to read each battery voltage of the 48 volt electric propulsion bank. Because I decided to use a bigger box to house the meters I added a dc current panel meter. Since since the wiring and space would allow it I also added a meter to measure the  whole pack voltage too:

Here is the unfinished panel with the whole pack meter installed showing the position of the other meters:


Finally the panel painted with the completed meter cutouts and installed in the BUD Polycarbonate boxl:


I did a quick test of the panel voltmeters on the bench  before installing them in the panel:


A word here on the meters I choose. I purchased five digital panel meters that could read up to 99 volts like this one. I realize now that I only needed one of these not five because four of the meters would only be measuring around a nominal 12 to 14 volts so buying a meter that measures up to 99.9 volts was really overkill. I could have saved a few bucks by buying cheaper digital panel meters that only measured up to 30 volts or so  like these. The advantage being that they only had two wire connections as opposed to the meters that read up to 99.9 volts which had four. Though when using them in a 12 volt application you just twist the meter power and measuring lines together and the same with the two ground wires. So other than a few extra bucks out of my pocket it was not a real critical mistake. Still it was money I did not need to spend  but, oh well. So it goes.
Another thing about the panel meters I should mention is I choose red as the color for the display. The reason being since the meters would be installed at the helm in the cockpit I wanted to minimize the loss of night vision for the helmsman when checking the battery bank at night. More on the wiring the instrumentation panel in the next post.


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