High inrush current for LED lamps
Verfasst: Samstag 14. November 2020, 10:52
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Why could there be problems switching capacitive devices.
Question: I only connected 150W (50 LED lamps) to the socket. It's only 0.65A, but the sockets are designed for 10A.
Answer: The LED lamps and switching power supplies work (mostly) as follows: The mains voltage is rectified with a diode (s) and smoothed with a capacitor. The up to 400V DC voltage is then "processed" further. Because the capacitor is discharged, it creates a short circuit in the first microseconds.
It can flow 100 times more current than "normal": 0.65A x 100 = 65A via the contacts of the relay (which are trembling about to close).
We have developed a NET-PwrCtrl ZX. We kept the safe relays
and equipped them with a zero-crossing switch.
LG Andy
Why could there be problems switching capacitive devices.
Question: I only connected 150W (50 LED lamps) to the socket. It's only 0.65A, but the sockets are designed for 10A.
Answer: The LED lamps and switching power supplies work (mostly) as follows: The mains voltage is rectified with a diode (s) and smoothed with a capacitor. The up to 400V DC voltage is then "processed" further. Because the capacitor is discharged, it creates a short circuit in the first microseconds.
It can flow 100 times more current than "normal": 0.65A x 100 = 65A via the contacts of the relay (which are trembling about to close).
We have developed a NET-PwrCtrl ZX. We kept the safe relays
and equipped them with a zero-crossing switch.
LG Andy