Ok, I don't know what I would expect from such a power controller for so little money, but the components used have been significantly revised. There is old silicone glue on the lids and small dents on the sleeves. One is already a bit dusty! At the heart of the circuit is the 555 timer, which is a good game when it works, but a little surprising. The SB10150CT provides adequate transient protection for driving inductive loads. Switching seems to be done by two or three D4184s with a maximum voltage of 40V, so I'd stop below that for safety.
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