Volt & Ampmeters:
The voltmeters and Ampmeters were purchased from different suppliers and require separate 5v power supplies. (Separate 5v power supply for the voltmeters and a separate one for the Ampmeters.
Can be purchased at
www.mpja.com and require an external 5v DC power supply:(YOU MUST GET
SEPARATE 5V SUPPLIES TO POWER THE VOLTMETERS AND THE AMPMETERS!! DO NOT
USE A COMMON 5V SUPPLY TO POWER BOTH A VOLT METER AND AMPMETER!)
Under Panel meters -> Digital -> Model 12308 ME
Can be purchased through www.ebay.com from the following supplier: http://stores.ebay.com/watershop168
They are listed all the time and when current ones end, new ones are posted.
They usually have some that are listed at $9.90 with $7.50 shipping ($17.40
total) and others that are buy it now for around a total price of $22.00 or
more. The thing to do is just place a bid for the $9.90 and let the
auction end. From my watching these for some time before I bought mine,
everyone just takes their turn and does not compete for a single meter.
I've purchased four and received all very quickly, despite the fact they are
shipped from Hong Kong.
5V DC Meter Power supplies:
Can be purchased through www.mpja.com .
Power supplies(various Wall plug types):
The 5v DC one I purchased last time:
Under Power supplies -> Plug supplies -> Model 16172 PS
How to install the meters: (VERY IMPORTANT, MUST READ)
As stated before, it is critical that you use a separate power supply for the voltmeter(s) and a separate one for the ampmeter(s). You can power multiple voltmeters with a single 5v power supply and multiple ampmeters with a single power supply.
The voltmeters have two separate pairs of board contacts on the back that are clearly marked to indicate which set is for the + & - of the 5v power supply and which is for the + & - for the sense input from the power supply that is to be monitored. Simply solder the correct wire connections from the 5v power supply and power supply (monitored) to the correct locations and you are good to go.
The Ampmeter is marked to show the proper polarity of the pins on the back for
the 5v supply (and that it is for the 5v input), the other sense side has a +
and - designation and the + goes on the side of the shunt that connects to the
track and the - goes on the otherside of the shunt that runs back to the power
supply. The big key is the shunt goes inline on the Negative wire not the
+. YOU WILL BLOW THE METER IF YOU INSTALL THE SHUNT INLINE IN THE +
I blew my first one when I connected my Ampmeter to my voltmeter 5v DC power supply and installed the shunt it inline in the 24v train powersupply + lead. The Ampmeter and one of my voltmeters blew before I could get it turned off. (After I had my my meter meltdown, MTH_Jim explained to me what I did wrong. Thanks Jim.)
5v Power supplies:
These will typically come with a single round plug on the end for use in some standard device they were intended for. Simply cut that connector off, plug into an outlet and probe with a voltmeter to determine which wire is + and which is -. This is critical, as you will blow your meter if hooked up incorrectly! Next, strip back the insulation and solder to back of the voltmeter or connect to the provided wires of the ampmeter.
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