good evening YouTube so I'm taking a look inside my variable AC power supply here I'm getting ready
to install this pze ma0 21 a seat panel meter and that was going to replace the 0-60 one meter that
I had in here and I thought the installation would pretty much be a plug-and-play the only thing I
had to install on the Oh 60 one meter was I took this wire off the ammeter here and ran it through
the current transformer and I thought I could just simply cut this wire and run this current in and
out of the panel meter here so it's it shows here's your load current on the outside so I
thought I could just run that load current through there but one of the things I want to do with this
meter is I want to power this meter separately from the variable voltage so that I can read the
voltage down to zero volts to do that requires a little modification and I'll show you this in a
separate video but what I need to do is disconnect this capacitive dropper which is the power supply
for this meter and feed this need on the capacitor separately from this input connector so I have to
run a fifth wire out of here basically and I'll show you that in a bit but what that means is
I've got constant voltage coming in here and then in the center I've got line and neutral
that the meter is reading the voltage of so I've got basically two line connections but I've only
got one neutral connector so now all of a sudden it matters which of these pins is lying in neutral
because on this wiring diagram they actually don't label which one is lying in neutral because if you
wire it up like this long as you got lying on one side neutral on the other side it really doesn't
matter which is which so I'll show you a little diagram of this in a bit but the other thing
that matters is what is lying in neutral inside of this power supply how is it wired so here's
your incoming power cord got your green earth or ground wire and then the these two wires the
line and neutral come in and down here there's a fuse so the line goes through the fuse then
down at the bottom there's a double pole switch and those wires run over here to the isolation
transformer so there's the 120 volt winding down here and then there's a an isolated with a
plastic insulator a separate 120 volt winding up here so these are the isolated line and neutral
connections that comes over here to your very act this is where you get your variable voltage
this is the neutral connection and then a hundred and twenty so I actually labeled them neutral in
line and then this pin here picks up wherever this lighting contact picks up voltage all the way from
zero clear around to a hundred and fifty volts roughly yeah there I've tipped up the power supply
a little bit so here's your ammeter wire comes from the variable voltage on the very act to the
ammeter and then the ammeter the other side goes over to the power plugs the receptacles and feeds
the hot terminal and then the neutral terminal comes over here to the volt so the voltmeter
sits between the hot and the neutral or lying in neutral on the receptacles and then there's a fuse
down there right down here is a fuse and then that comes back over to here to complete the circuit so
that's your isolated neutral and then this is your isolated variable voltage to your plugs
here so let me show you a little diagram I drew up hopefully well show what we've got here so here's
the variable supply you've got your incoming line and neutral there's a fuse a double pole switch
this is your isolation transformer and then over here you've got your line and neutral connection
at the very act here's the sliding contact goes through the ammeter over here's your voltmeter
between the line and neutral here's your two receptacles the hot the line the neutral back
through the fuse back to the very AK that's your variable output side and then here's the the panel
meter and here's the four terminals so here's the back side of the meter here's your your four
terminals this is your line side both of these are tied together this is your neutral side and this
is a 1 milli ohm resistor so here's your 1 milli ohm since resistor an R 0 0 1 and then these two
terminals are right here shorted together that's your line this feeds a 1 micro farad capacitor
which is this yellow thing and then a 51 ohm resistor here and this basically feeds your
power supply that powers this meter so you can see this meter has the current sensing on the neutral
side it picks up the load back through the sense resistor and back to the neutral this power supply
has the sensing ammeter on the line sighs so what I need to do is I've actually got to cut two wires
so I've got to cut the ammeter wire this will be my line connection down here the other side of the
wire that I cut will go back in here that'll be connected back together because these two pins are
shorted right there and then I'll have another cut in the wire this side is the load returning and
then this side of the wire is the neutral the load here is whatever you plug in to your outlets here
and there should be another ground so these are your two receptacles and here's your this is your
power so here's my power connection so this this way the meter will be powered by 120 volts all
the time so yeah it gets a little bit complicated because this power supply is set up with sensing
current sensing on the line side this meter is set up with current sensing on the neutral side
and with this very hour everything's referenced to the neutral the neutral is the only thing that
stays constant the big thing is I want to see on this meter I want to have zero volts zero amps and
zero watts I want three zeros showing on there so that's the goal of this project we'll take a
look at that when I get to cutting some wire so yeah if you have any questions about that
post up in the comment section below and stay tuned for the next video you can subscribe to
the channel to be notified when that video is posted and as always thanks for watching