The Volkslicht "people's light" (Patreon)

Inside a German "Volkslicht" (The people's light.) - with schematic

The Volkslicht was presented as the people's light, where the marketers probably thought that the German people would embrace their new light and buy them en-masse. They didn't buy them en-masse and are now selling off the excess stock. Special thanks to Kai-Steffen for sending me some of these so we could explore them. The light itself is a classic looking 6W warm white lamp with four LED filaments. The design is very typical for smart lights, with a bluetooth or WiFi module controlling the LED current regulator. In this case the device is based on a Bluetooth module and does not need a WiFi connection, although the app does require you to sign up with your email address and a password. In use, you create zones on your phone - like kitchen, lounge, bedroom etc. And then add lights to the desired zone by linking to their Bluetooth connection. During this process the lamps blink to indicate which one is being paired. You can then switch them on and off or control their intensity as desired. The pairing process was actually fairly straightforward compared to some of the earlier products, and the app sent a software update to the lamp when first connected. As with most of these smart lights, the circuitry splits into three distinct sections. The LED driver, the wireless module and a 3.3V power supply for the module. Control of the intensity is done with a PWM signal from the wireless module to the LED driver. Kai measured the PWM frequency as 1kHz. Linear regulators are ideal for this application, as they are small and simple. But with the fairly significant amount of electronics in such a small area, the lifespan will be directly affected by how brightly you run the lamp. I always recommend setting them at an intensity lower than maximum for a longer lifespan. In hindsight, the resistive divider and LN input may be tied into the capacitor charge circuit, and may limit the voltage it is charged to. That would lower heat dissipation and allow it to auto-compensate for a wider supply voltage range. Kai found that the bluetooth module is an EWN-8250FGT1HA which looks like a fairly capable Bluetooth mesh system on chip module. The app seems quite "persistent" and seems to want to stay running in the background, which may impact your phone's battery run time slightly. That said, modern Bluetooth systems are much more efficient than the earlier ones. It also requires your location, probably to ensure that it is only active in areas where you have lights registered. I think the main reason this product was less of a success than desired is that most people are happy to just switch a light on and off at the wall. The increasing amount of home automation products introduce a layer of complexity to your home electrics that will only appeal to home automation geeks (and hackers). The Ledvance brand originates from the Osram brand and is now owned by the Chinese MLS Co. If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:- http://www.bigclive.com/coffee.htm This also keeps the channel independent of YouTube's algorithm quirks, allowing it to be a bit more dangerous and naughty. #ElectronicsCreators