Golden Mini monitor

[menace]

I would like to get this little sucker up and running--its a toei Tc-V806A monitor and I have the transformer that went with it but not the connectors.  So what I need to know is what leads on the transformer correspond to input (from the wall) and output (16VAC to the monitor)  Shot in the dark here but I might get lucky.

[fredster]

I have no Idea what kind of game you are talking about, but isolation transformers usually have an up and down.

The down side has 2 or 3 posts. The two post is the AC IN,  the top ones are AC out.  

[Edgedamage]

I would like to get this little sucker up and running--its a toei Tc-V506A monitor and I have the transformer that went with it but not the connectors.  So what I need to know is what leads on the transformer correspond to input (from the wall) and output (16VAC to the monitor)  Shot in the dark here but I might get lucky.

Hmm sounds like I gotta get my butt over to my folks place AKA storage. And get you pinouts I will try ASAP.

[MonitorGuru]

Sounds like he's not only talking about an isolation transformer but also a step-down one.

I assume said "Mini" monitor is a tiny sub 9" monitor that could have been powered by batteries like portable televisions?

In that case you need a step down transformer that will first isolate from the mains (any standard transfomer does that) but also decrease the voltage due to different amount of windings on the primary and secondary side of the transformer.

You'd need a 7.2:1 to 7.7:1 to convert 115-125 VAC to 16VAC

I would assume the transformer has numbers on the side of each post.  If you could post a picture of it I'm sure I or someone else could tell you what is what.

Without a picture , here are some GENERALITIES.  Take them with a grain of salt and test before plugging in to ensure correctness.

1) The 120VAC input side *MAY* have thicker wire leading to the terminals (either from the outside to the terminal if any was left on it, OR leading "into" the transformer)   The 16VAC output would have thiner wire.  (But that does assume an amperage drop--thickness of wire = amp carrying ability and NOT voltage)

2) The 120VAC input side will generally have 2 or at most 3 terminals. One would be labeled N (eutral) or 0V and the other 110V,115V,120V,125V or H (ot). Another one may be labeled G (round) in RARE cases, though this is normally the frame of it.

3) The 16VAC side will generally have more terminals, but if a straight converter, it will only have 2 out.  There may be a third labeled "center" which takes out half (8 volts) or there may be many others furnishing who knows what output... e.g. it could be a 32 volt transformer with outs at 8, 16, 24 and 32, giving you 5 pins or something similar.  These should be labeled approprriately.

4) On units I've seen , the input is generally on the BOTTOM (against the board it's mounted on) for AC in, and the output is on the top, but this is not always the case.


You can test the resistance of the windings to find out which ones are connected together and which arn't (just set your digital ohmmeter to OHM and with nothing plugged into it touch every combination of tabs.)  Those with a higher resistance will mean the wire is longer or narrower and could help you determine what is what. Those with infinite resistance will not be connected together and usable as a pair for input or output.   Be sure you set your ohms at low ohm readings and not Kiloohms as you might get "0 resistance" readings even though there is some because the meter isn't at a sensitive enough level.

[menace]

Edgedamage:  any pics you can get of the insides or whatever would be GREATLY appreciated  

here's what I'm taking about: the transformer

[menace]

the tube back (the pins in lower left hand corner are for power in--but what pin is what is what i want to know)

[MonitorGuru]

Ahh... you don't have a block transformer, you have a switch-mode power supply of sorts.

(Though I can't see a mini on-board isolation transformer, so I think you may still need to supply power to this in isolated form--perhaps Ken Layton can provide more info)

The AC in appears to be at the top of the picture... the 3 wire plug, red, green? black.

There are a couple large filter capacitors, and what looks like a bridge rectifier (the large flat silver/black thing sticking up in the upper left--a grid of 4 diodes).. This leads me to believe that this is converting AC into DC since that's the component used (or 4 discrete diodes).  I think this is more an AC->DC power supply and not an AC->AC converter

However I do see 2 sets of outputs? on the board. One on the left, and one on the right. Perhaps some are AC some are DC, but I dont know which.

Without seeing the traces and testing this myself, I cannot conclusively say what it is or what it does or how you connect it.  Perhaps Ken can shed some light.


As far as which pin does what on your monitor, you could figure out a couple basic ones by following traces.  The one leading to the fuses from the pin header is likely the hot wire, and the one leading to any frame or heat sink connections may be the neutral wire, but I see that there are more pins than that. Therefore it may be accepting more than one voltage, perhaps even one AC and one DC...

I'd suggest googling for data sheets on this monitor before you go much further, unless Ken has worked with these and knows for sure.

[Ken Layton]

I'm drawing a blank on this one. Toei monitors are extremely rare in my part of the country (Washington state).

[menace]

IT'S ALIVE!!!!!  I'm still amazed that a few new caps can breathe life into these things...Now what to do with it...

[menace]

one for perspective (25" tube in behind)