A teardown of some rather neat little LED golfball style lamps for festoon use. These came from a seller called buyincoins_au and were £1.24 each. (about $2).
The construction is pretty robust with modest light output. no power rating is given, but they test out at a mere quarter of a watt.
The circuitry is a capacitive dropper with the unexpected cost and space saving feature of not having a rectifier. The six diffused LEDs are wired as two series circuits of three in inverse parallel, and current is limited through them by a 470 ohm inrush and transient limiting resistor and a 330nF capacitor with a slightly dubious discharge resistor across it. (1/8th watt).
this method of driving means that three LEDs at one side are lit on one half of the mains cycle and the other three on the other, meaning they oscillate rapidly back and forth. But the heavy diffusion means that this is not noticeable to the human eye.
These are actually nice lights. The intensity is actually quite acceptable for festoon style lamps. It's also quite unusual to find these with actual coloured globes.
The construction is pretty robust with modest light output. no power rating is given, but they test out at a mere quarter of a watt.
The circuitry is a capacitive dropper with the unexpected cost and space saving feature of not having a rectifier. The six diffused LEDs are wired as two series circuits of three in inverse parallel, and current is limited through them by a 470 ohm inrush and transient limiting resistor and a 330nF capacitor with a slightly dubious discharge resistor across it. (1/8th watt).
this method of driving means that three LEDs at one side are lit on one half of the mains cycle and the other three on the other, meaning they oscillate rapidly back and forth. But the heavy diffusion means that this is not noticeable to the human eye.
These are actually nice lights. The intensity is actually quite acceptable for festoon style lamps. It's also quite unusual to find these with actual coloured globes.