[time-nuts] Fluke monitor

GandalfG8 at aol.com GandalfG8 at aol.com
Wed May 12 19:32:21 UTC 2010

In a message dated 12/05/2010 17:45:16 GMT Daylight Time, Leigh at WA5ZNU.org  

The  monitor is a recent model and has the regulator. I left it on 
overnight,  in its original case and out in the open, hooked to a 13.5V 
supply. I had  it on a ammeter the whole time, and it never draws more 
than 0.02A.   The backlight is fine and the display works.

Something doesn't seem right with that current consumption.
Mine's not in use at the moment, as my test area is still stripped down,  
but when it was I measured a consistent 47mA once the regulator had a high  
enough supply to ensure it was regulating, in my case I was using 12 volts  
but the current is determined by the regulator output voltage so shouldn't 
vary  much anyway.
The display is what was fitted originally fitted to the iCruze module but  
the processor board has been changed so that Didier's Tbolt Monitor code can 
be  used.
The processor module circuit is pretty basic so I wouldn't have  thought 
there was too much room for a design error.
I'd be inclined to start by separating the processor board from  the 
display and then reconnect using a temporary link of flexible wiring so  as to be 
able to check if the processor circuitry is actually drawing  current, then 
I'd probably continue by looking for quality issues, bad  joints, solder 
bridges, etc.
If that turned up nothing obvious then a more in depth examination of what  
the processor is doing would be my next step, in particular it would be  
interesting to know how it's handling the RS232 interfacing just in case it's 
a  comms issue.
Given that Didier's code is freely available, and the processor board  
schematic is easily traced, it shouldn't be too difficult as a last resort just  
to build a replacement.

More information about the time-nuts mailing list