Voltage change for Eltek Flatpack2 48/2000 HE R5.3 SW: 3.00 ...

Post by coulomb » Sun, 27 Dec , 07:08

If you require additional information, please visit kelingyizhi.

solamahn wrote: '

Sat, 26 Dec , 22:55

I was under the impression that connecting a laptop to the CAN bus was possible.

I apologize for overlooking the CAN bus during my earlier search. Connecting to it is quite feasible. Numerous wallet-friendly CAN to USB adapters can facilitate this. However, the challenge lies in the method of communication with the USB. Some adapters offer a serial interface, requiring you to transmit 12 bytes to convey one CAN message, with the first four bytes representing the CAN ID. Others may come with a DLL for interaction through function calls, which can vary in complexity. An alternative is employing an Arduino equipped with a CAN shield for interfacing or possibly offloading most of the work to the Arduino itself.

It's crucial to understand the structure of the CAN messages that the charger will respond to, which should be documented in the relevant manuals or guides.

Forum Index: Electronics: Driving Eltek 2kW Flatpack2 Supplies via CANbus

      Page 4 of 5       Posted: 10:30am
02 Jan

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nickskethisniks

Guru

Does anyone know if these PSUs can be directly powered by solar panels?
They feature a broad AC (or DC) input range and with a little ingenuity, I could convert one into a high-voltage solar charger.
I would place a (poida) MPPT controller behind it to monitor the solar voltage using an isolated op-amp or hall-effect sensor.

Posted: 06:49am
03 Jan

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wiseguy

Guru

Nick, that’s precisely how I’d approach it: keeping the solar PV power at its ideal operating point while charging optimally. Just ensure that the panels' open circuit voltage doesn’t surpass the Flatpack2's maximum input voltage of 300VDC.
I've demonstrated that they work perfectly with a DC input using a variac alongside a basic transformer/rectifier/capacitor setup.

Posted: 10:27pm
06 Jan

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nickskethisniks

Guru

Thanks!

Posted: 03:25am
25 Jan

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KENSTV

Newbie

I have the official Eltek schematic for the first page of the main board, but acquiring the second page would be beneficial as I’m also seeking the schematic for the control board. Although Wiseguy did provide some diagrams, they pertain to the original flatpacks, which have a significantly different control setup. I plan on modifying the circuit to consistently output a different voltage immediately upon plugging after the soft start. The Flatpack 2 HE’s control is managed by an ML56FT microcontroller. My intention is to manipulate the resistance for the voltage sampling back to the microcontroller's A-D converter, effectively misleading it into believing the output voltage is coded at 53.5V. There are four resistors concerning the output voltage and current feedback routed back to the standup board’s microcontroller—one of these should modify the voltage output sampling, so having page 2 would be greatly appreciated.

Keep in mind that these power supplies are sophisticated in design, with a highly intricate control circuitry, and the component scale is quite small, along with the multi-layer boards that add to the challenge of circuit modification. However, I believe this method is the most straightforward path to obtain a different output voltage without delving into coding, Arduino setups, and CAN interfacing.

It's essential to note that the modifications suggested in Thailand were meant for the older analog-controlled flatpacks, while the Flatpack 2 HE utilizes microcontrollers for monitoring and output control—there are two microcontrollers involved!

Posted: 08:21am
25 Jan

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poida

Guru

Are you aiming for 53.5V? This can be achieved without any hardware alterations, merely by sending Modbus commands.
A single Nano and a CAN bus module can do the job.

Should you require assistance, I'd be more than happy to help! It's quite straightforward.

Posted: 06:22pm
25 Jan

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KENSTV

Newbie

I sincerely appreciate that, Poida! As someone not particularly experienced with coding and unfamiliar with the Arduino Nano, guidance would be invaluable! My inquiries include:

1- Can you provide links to the files used on the Arduino-SPI to run the code? Does the SPI interface deliver the 60-ohm termination on the CAN lines?

2- Is it feasible to program the Flatpack 2 HE—version one—to retain the voltage configuration post power outage?

3- Does your code automatically retrieve the serial number, or do I need to identify the internal serial number and integrate it into the code?

4- I require a 50-volt output; what would be the necessary code for that voltage?

Additionally, I’ve noticed both microcontrollers have SPI interfaces on their respective edges, leading me to believe the parameters are established during manufacturing and that the firmware might not be tightly secured in those chips. The principal output control microprocessor is an MC56FV, whereas the smaller front-end microcontroller is a MC56F (which presumably oversees input voltage and fan control). Both are products of Freescale (acquired by NXP), and the 56F802X and 56F803X Peripheral Reference Manual is accessible, detailing the main microcontroller’s setup.

Posted: 11:07pm
25 Jan

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poida

Guru

Firstly, I'm not completely adept with these yet, so there might be some inaccuracies in my recollections.
Parts utilized:
A basic Chinese Nano with the CH340 serial-USB chipset.
Driver for Windows:
CH34x_Install_Windows_v3_4.zip
A MCP CAN to SPI module.



Software:
Arduino IDE (my preference is for the legacy version 1.8.19).
CAN - SPI board library (attached below).

Program for the Nano:

Eltek_set_perm_voltage.zip


Steps:
Install the Arduino IDE.
Add a library in the .zip format; specifically, add the aforementioned MCP_CAN library.
Install the CH34X driver.
Connect the Nano and ensure you can load and run programs. Usually, it's required to select "ATmega328 (old bootloader)" as the processor.

Connect the MCP module to the Nano using six wires: ground, 5V and the 4 SPI connections: chip select, clock, MISO, MOSI.
The program contains the SPI to Nano pin information.

The core of the program revolves around sending a single Modbus command.

..
unsigned char setdefaultvolt[5] = {0x29, 0x15, 0x00, 0xc0, 0x12};
..
CAN.sendMsgBuf(0xC04, 1, 5, setdefaultvolt);
..

The last two bytes of setdefaultvolt represent the voltage we want, starting with the low byte.
Thus, 0xc0 and 0x12 represent the default voltage value, which translates to 0x12c0 in decimal form, equating to the desired voltage in hundredths of a volt.

Initially, to enable operation of the Eltek setup, it must first "log in" utilizing the serial number located on the Flatpack's label.
My serial number appears as:

To initiate communication, the serial number forms part of the login procedure.

..
unsigned char login[8] = {0x16, 0x36, 0x71, 0x07, 0x03, 0x76, 0x00, 0x00};
..
CAN.sendMsgBuf(0x, 1, 8, login); ' '// id = 1; thus, XX = 04
..

Eventually, it is necessary to adjust the program to accurately reflect your distinct serial number, in addition to revising the default voltage values as needed.

After modifications are completed and uploaded, power up the Flatpack, observe the output voltage, and then reset the Nano. This will execute the program and halt.
IMPORTANT: Disconnect power from the Flatpack and wait 20 seconds to ensure the CAN bus within the Flatpack ceases operation entirely.

Once power is reapplied, the modified output voltage should be visible.

I recently set up a makeshift configuration to validate everything.


You must connect Eltek's CANBUS signal ground to the MCP ground—this is crucial, or the MCP module may malfunction. I believe if this isn't done, it may lead to failure or other unforeseen consequences. I typically connect the ground to Eltek's CANBUS signal ground.



Responses to inquiries:

Refer to the provided code above. You must join two pins on the MCP board to establish the requisite resistor termination, or else it won't function.

It's indeed possible to program a new voltage that persists through power interruptions.

My code does not auto-read the serial number; I haven’t bothered with that aspect. The code fulfills its purpose; simply ascertain the label, then adjust the code.

For a 50V output, convert the value to hundredths, referencing the appropriate byte order in the setdefaultvolt array.

I trust I have facilitated your tasks significantly.

Posted: 11:21pm
25 Jan

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KENSTV

Newbie

Thank you for the straightforward guidance. I have already placed my order for the boards.

Posted: 11:31pm
25 Jan

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poida

Guru

FlatPack2_Schem.png.pdf

And I managed to find more schematics as a bonus.

Posted: 06:24pm
01 Feb

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KENSTV

If you wish to delve deeper, please check out our site at eltek flatpack2 voltage adjustment.

Newbie

I appreciate you preventing me from modifying it unnecessarily. I possess an extensive range of skills and tools for soldering and rework; however, working with lead-free solder in these Flatpacks necessitates considerable heat, which would have complicated the task at those control board pins. I'm confident I could have merely adjusted the feedback voltage sample to the microcontroller, but programming time is more pragmatic.

I've noted that the red beacon symbol LED is now blinking, suggesting the Flatpack is attempting to communicate with the controller. According to the manual, the red LED signifies that the "Alarm LED is ON (shutdown or similar critical alarm)." I do not recall the red LED lighting upon initial power-up.

Perhaps the Flatpack requires an ID number assigned, but I’m uncertain if the code accomplished this.

Additionally, the fan is excessively loud; I plan to reduce voltage using a resistor. The four-wire fan relays information back to the microcontroller regarding its operational status. The other two wires connect to a hall effect sensor, which, as I suspect, doesn't measure pulses but rather detects the absence of pulses.

Once more, thank you!
Edited -02-02 07:13 by KENSTV

Posted: 04:35am
12 Jul

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Sinar

Newbie

Hello,
I’m a radio amateur from Romania seeking to use the Flat Pack2 (48v-W) power supply for a power amplifier. Unfortunately, the default voltage is excessively high, and I'd like to make adjustments.
Kindly clarify how to connect the CAN transceiver to the Flatpack2. Is it appropriate for Can HI and Can LOW to connect to the -DC output, or should they go to the CAN bus's GND?
Thank you in advance,
Romeo - YO8RAW

Posted: 12:47pm
12 Jul

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KENSTV

Newbie

The ground for the CAN bus and the DC- are indeed interconnected. Just reference the board’s foil; the voltage only dwindles to a certain level—42V appears to be the minimum, but I can’t find my notes. Perhaps someone might recall the least programmable voltage option. It’s paramount to note that these power supplies are inherently noisy due to their fan assembly; if operating below higher currents, utilizing a quieter fan that doesn’t produce as much airflow could be advantageous. The power supply is notably efficient and remains relatively cool under lower loads, but the fan's noise can be intolerable unless situated in a distant location, like a cell tower installation!

Posted: 03:23pm
12 Jul

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Sinar

Newbie

I appreciate your prompt reply. I’ve crafted the board for power supply connections, granting me access to the relevant power supply contacts. Nevertheless, since modifying the output voltage rendered it unusable due to soldered wires, I discovered a substantial (infinite) resistance between -DC and GND CAN BUS. I'm uncertain about the construction of the connection boards available on eBay, yet after studying various forums, I find myself confused. I attempted to program the power source (not personally, but a friend helped since programming isn’t my forte), connecting -DC to both GND CAN BUS and CAN BUS transceiver ground, but I was unable to establish communication with the supply. It issued the message, "CAN BUS shield init fail," leading me to believe there might have been an error with my hardware connections. I have ordered an additional CAN BUS transceiver to see if that resolves the issue.

Thank you for your assistance,
Romeo

I apologize for using Google Translate.

Posted: 09:07am
13 Jul

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nickskethisniks

Guru

I developed boards utilizing separate grounds, although provisioned a resistor to connect with the power ground. In my case, the microcontroller and transceiver are powered via an isolated power supply, yet these two grounds remain unlinked. I believe I read somewhere that it's ideal to connect both power and CAN bus to a common ground, possibly through a small resistor interspersed if managing multiple devices in parallel.
Edited -07-13 19:09 by nickskethisniks

Posted: 09:23am
14 Jul

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Sinar

Newbie

nickskethisniks
I aim to use just a singular power supply for my application; however, I still don’t fully comprehend your explanation. If it’s not too much trouble, could you illustrate a connection diagram based on your setup? As of now, the noise from the fan is not an issue for me; the power supply shouldn’t operate in max mode continuously.

Posted: 12:39pm
14 Jul

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Ziki_the

Newbie

As the discussion unfolds, is it feasible for use with Eltek PSR 327? It resembles the older Flatpack model. I possess four units of 48V, 56A, 2.7KW currently stored and would think that adjusting them would be worthwhile. They could serve as a test setup...

Posted: 07:02pm
22 Jul

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Sinar

Newbie

Following the guidelines on this forum’s fourth page, I successfully adjusted my Flatpack to the desired voltage. Thank you for the help!

Posted: 04:29pm
14 Aug

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Arthur_Dent

Newbie

Greetings,
Has anyone gained experience with load sharing using the Eltek Flatpack 2HE Front End? (For instance, connecting two rectifiers in parallel for redundancy and similar applications)

I possess a couple of Flatpack 2 Front End Rectifiers featuring FCI/Berg style connectors. Among these pins is ISHARE, purportedly allowing "Systems to utilize the CAN bus for digital load sharing" (according to Eltek documentation, Issue 1, published 17-May-12). The V series rectifier guide elaborates further on this: "All rectifiers' ISHARE pins are interconnected on the system backplane to support load sharing. This connection can either be terminated between rectifiers or left un-terminated in settings where load sharing isn’t needed."

Is anyone aware of how this function operates?

I look forward to your advice.

Posted: 12:48am
15 Aug

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poida

Guru

I have no insights regarding the CAN bus share function

However, I have successfully operated them in parallel as anticipated. One unit delivers power up to its limit, followed by the other, contributing power to meet its capacity. Achieving an exact load distribution is nearly infeasible. One of the units will monitor the output voltage and shift to Constant Voltage mode before the other does.

Additionally, I have tested them in series without complication; the outputs remain isolated from the mains AC input, eliminating any issues. Nonetheless, caution must be exercised to ensure the CAN bus ground and signals are not interconnected while operating in series. Reaching 115V DC at 45 Amps presents considerable risks.

Posted: 03:34pm
15 Aug

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Arthur_Dent

Newbie

Hi Poida,
I appreciate the clarification. I believe this setup would work for my purposes.

Nonetheless, I'm still intrigued by the workings of the ISHARE feature—if anyone has insights, I'd appreciate learning more!

For further information, feel free to explore eltek always on and reach out to us for expert advice!