Note that the op’s application involves equipment rated for operation at either 50 or 60 Hz, and the frequency conversion is not required.
In order to support both 50 Hz and 60 Hz standards, the device needs to be rated to work at least within frequency range from 48.5 Hz to 61.8 Hz. This is because it needs to support allowed mains frequency variation ±3%.
If it really supports all frequency range which include both standard, then he can use 1:2 voltage transformer. But it requires that device needs to be carefully checked and tested in order to comply with both frequency standards.
Radiolistener, can you delete your posts?
Once again, did you read the thread? It was figured out already that the device is using switching power supplies which support both AC voltage and frequency variants on the input.
These PSU can be used directly. But this is just 750W power consumption.
There is also another possible issue which is critical for medical devices, even if he using PSU which all are compatible with all mains standards, it still needs to be tested with both mains frequency. Note that the mains frequency has leakage through PSU in a form of a ripple and/or interferences and can affect equipment functions, especially if this is device which uses sensitive measurements.
For example precise ADC can have configurable rejection filter which can be software configured for 50 or 60 Hz depends on user environment. And it needs to be taken into account very carefully especially for medical devices (which is the case for topic starter question). And this example is not abstract this is example of a real case for medical devices.
There is a mains input filter in the design. Described earlier in the thread.
Adding an external transformer voids the 60601 compliance.
You might want to plug the device into a Kill-A-Watt and measure the power consumption under full load. I suspect it won't be more than 1000 W, but this way you can measure it and find out.
I'm afraid that such approach is not acceptable for safety critical devices development because it don't guarantee that device will never consume more power under some specific conditions.
But if you can't identify and test what those specific conditions are, then the device could never be certified?
Also, it has not been specified that a robotic gait trainer is a safety-critical device. If it stops working for any reason, it is hard to see what harm would come to the person using it.
I'm afraid that such approach is not acceptable for safety critical devices development because it don't guarantee that device will never consume more power under some specific conditions.
Undefined/unspecified behavior of device is not acceptable because it is unpredictable and can make harm to the patient. This is uncontrolled potentially life threatening risks for the patient and it's presence shows serious issue in validation/verification process and broken quality management system.
The above two statements are in contradiction with each other. Either you can specify the designed behavior, or you cannot. If you specify the behavior, then you cannot also say, "but this is unacceptable, because it may behave in ways other than those specified".
In order to support both 50 Hz and 60 Hz standards, the device needs to be rated to work at least within frequency range from 48.5 Hz to 61.8 Hz. This is because it needs to support allowed mains frequency variation ±3%.
…Once again, did you read the thread? It was figured out already that the device is using switching power supplies which support both AC voltage and frequency variants on the input.
Radiolistener, can you delete your posts?Unfortunately, that would mean him admitting he's mistaken and going by his posting history, is something he appears to be unable to do.
In order to support both 50 Hz and 60 Hz standards, the device needs to be rated to work at least within frequency range from 48.5 Hz to 61.8 Hz. This is because it needs to support allowed mains frequency variation ±3%.
…Once again, did you read the thread? It was figured out already that the device is using switching power supplies which support both AC voltage and frequency variants on the input.Radiolistener, can you delete your posts?Unfortunately, that would mean him admitting he's mistaken and going by his posting history, is something he appears to be unable to do.
I find it quite remarkable how someone whose username is “radiolistener” can be so very bad at listening!
My favourite one was when it took several pages to explain why a capacitor connected to a generator doesn't increase the power consumption, ignoring the tiny extra I2R losses.
My favourite one was when it took several pages to explain why a capacitor connected to a generator doesn't increase the power consumption, ignoring the tiny extra I2R losses.
My favourite one was when it took several pages to explain why a capacitor connected to a generator doesn't increase the power consumption, ignoring the tiny extra I2R losses.
For what reason you're writing it in that way like I was claimed that capacitor will consume the power? This is false. I didn't claimed that.
No, the wording doesn’t say the power consumption is in the capacitor
just that you thought adding the capacitor increased power consumption in total
Which is something you stated in the thread over and over and over.
We could substitute “reading comprehension” for listening, and you just proved our point: you don’t listen, or in this case, read carefully. You’re seeing what you want to see, not what’s actually written.