T
treez
Guest
We have a 60W offline , isolated , Flyback LED driver. The LEDs are mounted on MCPCB, which is screwed into an earthed heatsink. The output ground of the LED bank is not connected to earth. We believe that the output “ground” could unfortunately float up to a high voltage (Mains peak voltage ) , and we don’t want this. Therefore, we thought about connecting the output “ground” to Earth. However, this means having another connector and its too expensive. Therefore, we wish to have a compromise…..what we want to do , is to simply connect a 1 Megohm axial resistor , with a suitable voltage withstand, across the isolation barrier under the Flyback transformer. We will connect it between output “ground” and [Primary DC bus “ground”]. I admit that that is not the same as tethering the output “ground” to earth, but at least it should stop the output “ground” from floating up to mains peak.
As you know [Primary DC bus “ground”] is actually connected to Mains Neutral for 10ms, then to the negative_going mains live for the next 10ms , repeating. As such, we believe that the average voltage of [Primary DC bus “ground”] is actually around minus 107V…..this is better than mains peak. Do you think that this is a good idea?
As you know [Primary DC bus “ground”] is actually connected to Mains Neutral for 10ms, then to the negative_going mains live for the next 10ms , repeating. As such, we believe that the average voltage of [Primary DC bus “ground”] is actually around minus 107V…..this is better than mains peak. Do you think that this is a good idea?