(dang, TERRA kicked my post to nowhere)
Underneath of meters is a step down isolator(SDI-CS), unused third Tf in front of it.
(from single battery offline UPS, 14V primary)
Weight is few kilos and middle size stuff, between it and Tfs for 180V supply, is missing.
It's dropping less than 10%, so most likely within the range.
Simpson on right must measure day in day out to stay in a ballpark, now it's monitoring AC for meters.
AC must be one the edge somehow since those meters are starting in sequence when cold.
Topmost is different and is a slowest starter, but all are showing left half first, measurements are already going on in the background.
Maybe that can teach something.
SDI,
these plastic boxes are almost very practical, this one is not deep enough.
Thick red is a center tap and source for step up side.
Using blue wire, lower original output, for input will rise output too much, or maybe not but I like it more this way.
Side note,
if nothing else then that robust test clip show its robustness.
(low left)
China goods 7660S DC/DC negative converters have also arrived, front bag with barcode.
Everyone is overheating without output, price was less than 1/10 of a real one, but minimum amount was 10.
Quantity over quality, or how was it.
Boost converter is also here, so meters initiation as real TEs is for the future, since long time test is already on and so PXP-GL construction is on hold.
Voltage is around 188V and divider for voltmeter is set to 1.2mA, what is also a real consumption.
Currently connected are plus sign and keep alive.
Voltage over 150k limiting resistor can be measured against anode to be around 3V, against GND it disappears, but is still clearly more than nothing.
Don't know what this 20uA means, maybe cathode is so poisoned that this is all that can go through.
Obviously RS order is also here, and incomplete.
Capacitors came but regulators were dropped to backorder, January something.
Maybe I can add something without new P&P.
One other thing,
how do you differentiate panel display LEDs from not LEDs?
(both are pretty red when they are red)
I've used segment shapes and DP positions, it's obviously enough for these SP-things, but how it is with others.
Calculators seem to use single tubes or single full width modules.
(few expensive exceptions)
For now I think the 30A display will be somegraded.
Options are, for now, a VFD and other style of GDD.
LEDs would be too lame, for now.
One thing I did't understand first was minus and plus sign currents for 30A display.
Minus sign and DP are the same 135uA typical, but only DP is pulled through typical 270k giving ~167uA.
Minus sign has 62k, but it also goes through 2N5550 to ground and _POLEN is equally switched to GND.
DP tranny base is 5V through 100k so ~50uA when minus tranny has the same base resistor but from TTL output high.
If that output is say 3V it's still plenty for burning the segment, hFE 10 would already give Ic ~300uA.
Plus sign has higher limit but its tranny has also less than half of a collector resistor.
Then I read the manual and it's clearly a multiplexing thing, sort of.
Segment max is 250uA but can be increased to 650uA if multiplexed up to 1/4 duty cycle, says the manual.
But those resistor values are still too small, around 50%, and DP has also that same multiplexed anode.
Maybe I should test the display based on active current.
Seems that those panel meters have a change to do some real stuff alter all.
If I take the current route I obviously need a current limiter, clear case for under a volt measurements.
Then a historical anecdote,
Burroughs was greedy and wanted too much royalties, so Japanese companies created VFD.
And another other thing,
earlier blanked EPROMs are still blank, so pretty decent UV-lamp is that LED.
Then the last other thing,
one set of 3.81 spaced PCBs arrived.
Actually was only 1 of 5 and a wrong one.
E,
last picture was missing.
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Topic: Test Equipment Anonymous (TEA) group therapy thread (Read 35885493 times)
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