Identify what this is - Page 1
Forum section: electronics / repair

author: najrao
author_rank: Regular Contributor
timestamp: December 13, 2017, 05:01:06 am
content: Anybody?Unit has 800W PFC , and also outputs two a.c. hf at perhaps 4000+ volts. Not enough tested due to dangerous voltages, PFC works, but no more known. Teardown shows the PFC (with its own output jack), and two independent, fairly conventional mosfet bridge pwm inverters driving two ferrite core transformers. The secondaries thereof end up at output jacks. There is are complicated controls, RS232, a 'sync' jack and switch.I can only think of neon signs using such output.The name on the unit appears to be a company no longer in business.Thanks in advance.

author: Gyro
author_rank: Super Contributor
timestamp: December 13, 2017, 04:24:03 pm
content: It says output 385V at 2A so I suspect it's for some other form of higher power discharge lighting, maybe metal halide, high pressure Sodium etc. Definitely not Neon. The 4kV+ voltage you are measuring is probably the lamp ignition pulses.The RS232 port implies that it has remote control and monitoring - illuminating a building or something like that?

author: tru3533
author_rank: Regular Contributor
timestamp: December 13, 2017, 04:38:31 pm
content: Hmm. my two cents is an universal CFL backlight driver for commercial display (advertizing?)

author: Nusa
author_rank: Super Contributor
timestamp: December 13, 2017, 05:50:04 pm
content: Maybe shots of the input and output jacks would tell us what kind of equipment it is intended to interface to.What do component date codes tell you about the age of the device?Is the RS232 port generating an output? Perhaps there's a text stream that's revealing. If you're really lucky, a full-fledged menu system.The fact there's an h-sync switch and adjustment suggests analog video processing.The switch chart suggests older projection display sizes and lamp sizes with PWM brightness/power control.

author: najrao
author_rank: Regular Contributor
timestamp: December 14, 2017, 04:00:48 am
content: Thanks friends.Other than the 385V dc, the only outputs are at two small jacks visible at top left in the first picture. Each of these is just a 6pin header with only the end pins retained. I have the connecting wire harness too, not showing in the pics, and the high voltage wires are just 24AWG Sumitomo 105C with only 0.5mm Insulation thickness. I cannot see how they will stand the expected several kV.I have NOT attempted to measure the voltage. Nor do I know how to use the RS232 signals if any. Sad.Lamps, yes, but what sort? Each output seems good for at least 300W, and there is the high frequency to consider.It is likely that the 385V dc output is available ONLY if the others are turned off, and there is a mosfet switch inside which can do this. Thus, the maximum power is limited to 770W.The pcb has a date code 09.10.09.I really need to get into it some more, especially the RS232; I can certainly establish the pwm frequency and look at the voltage on the primary side. I do have an AVOmeter which can take 2kV a.c., and may be able to augment the range by external dropper. Need time.Do think out of the box, and let me know if more pictures/detail will strike a.chord.

author: TerraHertz
author_rank: Super Contributor
timestamp: December 14, 2017, 07:00:09 am
content: Have you tried googling for the model number? I can't make that out in your pic.Date codes on parts, or on PCB will help make guesses on what it was intended for.To me it looks like something intended to drive one or two fairly large cold cathode fluoros, probably backlighting something.Something that needed precise and complex control of the illumination level.Something like a medical X-ray film scanner, maybe? Or an astronomical film digitizer/blink comparator?

author: najrao
author_rank: Regular Contributor
timestamp: December 14, 2017, 07:40:00 am
content: Yes, I have too, no results though by the Google route. The faded model number is OUSSIPdV2. The Korean characters don't help.This unit has had to be made in thousands, considering the quality of tooling for the case (aluminum alloy) and circuit boards.TerraHertz's suggestions are possible but I do not know enough about such sources of illumination.The table of switch positions on the case (see photo) says "lamp"; numbers 16, 20 --- 57 could indicate types (of lamps). Still, 300W each? Are there discharge lamps of whatever kind at this power level? What price the high frequency fed direct? Unless for some mysterious reason, there are rectifiers and things built into the 'lamps'.I already gave a date code, on the pcb: 09.10.09.I have just powered it up in a safe mode, and the PFC works well. With the correct switch chosen, the 385V dc shows up at the output, but only after a long time delay. Cause unknown, may even be intentional.The inverters appear not to turn on, with any switch combination as in the table; but the LED indicator marked "inverter" blinks rapidly, perhaps indication a fault. I suspect this 'fault' is external, i.e., in that it cannot work into an open circuited load, which is my test condition. I base this on having discovered that, while there is no voltage feedback, there appears to be a CURRENT feedback from the traansformer secondary. Each transformer has two secondary windings, connected at their low ends to the a.c. input of a small diode bridge. There are what must be current shunts as 51R resistors, feeding into a LM324 op amp. It is very difficult out to trace the actual connections.Now, I must find some way of loading the secondary to prove my point. Since the working ratings are not known even as guesstimates, I am at a loss to select a loading resistor. If indeed it is constant current device, a high load resistor is most inappropriate!I do not know of any discharge lamps that have a working voltage of more than a couple of hundred volts. Some, e.g., may need a starting voltage of 2kV or more to strike the arc, but this should drop to 100 to 150V thereafter. I want to stand corrected if I am wrong.

author: massivephoton
author_rank: Contributor
timestamp: January 13, 2018, 03:06:52 am
content: There's contact info for E-An Hightech on google:http://eanhigh1284.gobizkorea.com/catalog/about.jsp?blogId=eanhigh1284&pageNo=1&pageVol=12&listStyle=AEDITAlthoughthe contact says it manufactures CT and CAT monitors,maybe they could confirm after a phone call. [The OP already said they seem to no longer be on business]Keep us informed.Regards.

author: Cyberdragon
author_rank: Super Contributor
timestamp: January 13, 2018, 05:22:37 am
content: Quote from: tru3533 on December 13, 2017, 04:38:31 pmYes, I think it's a CCFL tube driver for something, which explains high voltage and high frequency. I see what appears to be inches on that chart, which I would assume refers to tube length.

author: stevelup
author_rank: Regular Contributor
timestamp: January 14, 2018, 06:14:38 pm
content: Those numbers are, coincidentally, very common LCD panel sizes (40", 46", 52"), and the number of lamps per screen look about right.

author: najrao
author_rank: Regular Contributor
timestamp: January 15, 2018, 04:16:27 am
content: I agree with steveIup, the numbers must be display size, diagonal.I am unable to get the inverters going without any loads connected. This may be intentional. However the dc output of the PFC gets going.I was wrong in asserting that each a.c. output is 300W, it is possible that they are meant for smaller loads. The PFC may be used to power other converters separately. We just do not know.To drive discharge lamps, the driver has to be a current control ballast, with high voltage available to strike the arc initially. In this case, it seems that the necessary inductance is offered as leakage inductance of the output transformers. There is no other component. The output winding is placed entirely clear of the primary, on the outer limbs of the EI core. The winding has a high resistance of 120 ohms, and cannot carry more than say 400mA limited by heating.

author: kathy45
author_rank: Newbie
timestamp: January 16, 2018, 03:49:32 am
content: Quote from: stevelup on January 14, 2018, 06:14:38 pmYou are right Stevelup . I agree with you. the numbers should be show size, diagonal..