Nevertheless, this could be a handy sensor, and it’s definitely a solid lesson in design. Still, if your tastes run more toward using this module on the 1.25-cm ham band, have a look at this ...

Here is the basic circuit diagram of the UV Sensor Module, drawn & checked by me (thanks to my USB microscope and LCR meter).In the circuit PD1 is the GUVA-S12SD, and U1 is the SGM8521. The only one ...

From the circuit diagram of the module, it is clear that, apart from the module only a few external components are needed to build a relay-driver circuit. Yes, there is a chance to realize one simple ...