Yet another destructive teardown of a random ebay gizmo. This time it's a sidelight or running light for a truck.
The device is glued together and the wire entry is double sealed. The PCB has two superflux LEDs running at just under 20mA with the wide voltage range of 9.5 to 30V catered for by a simple LM317 regulator in a TO92 package being used in current limiting mode.
At the full truck voltage of around 28V the regulator dissipated about 0.4W (400mW) which I thought was quite high for a TO92 package, but while the Internet is a bit vague about the actual thermal dissipation ability of a TO92 package, it appears to be able to handle about 0.5W in normal circumstances.
The device is glued together and the wire entry is double sealed. The PCB has two superflux LEDs running at just under 20mA with the wide voltage range of 9.5 to 30V catered for by a simple LM317 regulator in a TO92 package being used in current limiting mode.
At the full truck voltage of around 28V the regulator dissipated about 0.4W (400mW) which I thought was quite high for a TO92 package, but while the Internet is a bit vague about the actual thermal dissipation ability of a TO92 package, it appears to be able to handle about 0.5W in normal circumstances.