Durst power supplies EST 301 and EST 450

The regulator board of the ES301 has been inspected, revealing that the PCB contacts of the current sensing resistors R42 and R43 are severely burned. There is a nearby group of resistors that also need to be replaced, but their values cannot be read due to significant darkening, similar to the surrounding PCB. Two inverters have been returned from CCI, which have been identified as having bad capacitors. If not for liability issues with the manufacturer, repairs could have been completed in a few hours instead of waiting weeks. In addition to Mouser and Digikey, Newark is a reliable vendor for specific parts, offering capacitors and resistors at competitive prices and often faster delivery. Durst Pro USA provides replacement regulated power supplies for both inverters (EST 1500N-24). An alternative consideration is to replace these regulated supplies with a TRA450/TRA500, which functions as a transformer in a box. This component can drop to zero output, making a regulated power supply ineffective in such cases. Previous discussions have indicated that the value of regulated supplies is questionable for black and white printing, as it is simple to repeat prints if power is interrupted. There are inquiries regarding issues experienced with the unregulated supply, with a noted minimal difference in printing time between two black and white prints when compared side by side. A power outage lasting five seconds during a 25-second exposure still results in satisfactory print quality.

The regulator board of the ES301 is a critical component that manages the voltage and current supplied to various parts of the system. The damage to the PCB contacts of resistors R42 and R43 suggests overheating, which can lead to failure in current sensing and overall system instability. The presence of burned contacts indicates that these resistors may need to be replaced with components that can handle higher power levels or improved thermal management.

The nearby group of resistors, which are now unreadable due to discoloration, may also play a role in circuit stability and performance. It is essential to identify their values, possibly through circuit schematics, to ensure that replacements maintain the intended functionality of the board.

The mention of bad capacitors in the inverters highlights the importance of reliable components in power supply systems. Capacitors are critical for filtering and stabilizing voltage levels, and their failure can lead to significant operational issues. The recommendation to source parts from vendors like Newark, in addition to Mouser and Digikey, allows for a more efficient procurement process, particularly when urgent repairs are necessary.

The suggestion to use the TRA450/TRA500 transformer as an alternative to regulated supplies indicates an understanding of the trade-offs between regulated and unregulated power supplies. While regulated supplies provide stable output, they may not be necessary for all applications, especially when the system can tolerate brief power interruptions without compromising output quality.

In terms of operational efficiency, the ability to maintain print quality even with momentary power loss is a significant advantage in environments where power stability is a concern. The observed minimal difference in exposure times further emphasizes the robustness of the printing process, allowing for flexibility in handling power supply issues without sacrificing quality.Checked already the regulator board of the ES301 and it`s clear that the PCB contacts of the current sensing resistors R42 and R43 and severely burned. There is a group of resistors nearby which I would like to substitute also, but it`s no longer possible to read the respective value, as they have darkened considerably, like the surrounding PCB.

I just got two inverters back from CCI. Guess what Bad capacitors! If I didn`t have to deal with the manufacturer for liability reasons, I could have fixed these in a couple of hours instead of waiting weeks. In addition to Mouser and Digikey, Newark is a pretty good vendor to deal with too. I only order a few specific parts from them, but I can get my capacitors and resistors cheaper here, and usually faster, than from the other two.

Durst Pro USA has a replacement regulated power supplies for both of those (EST 1500N-24). Another thought is to forgo these regulated supplies and look for the TRA450/TRA500 which is just a transformer in a box: Actually it can drop to zero, in which case a `regulated` power supply like shown will give zero output. As I posted previously it is of questionable value with B&W printing. Simple to just repeat the print when the lights come back on. Perhaps you are mistaking these PMW regulated power supplies with some sort of emergency power system.

I`m also wondering what kinds of problems you are experiencing with that unregulated supply. I can only tell a 1/3 stop difference in printing time between two B&W prints when side-by-side. This means with a 25 second exposure the power can go completely out for five seconds during my exposure and I`ll still get a good print. 🔗 External reference