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Congratulations! Nice box. I ordered your parts list and am midway through building one myself. The relays are back-ordered and so I dug deeper into datasheets to look for another. During that process I found that the relays you used are rated for 10A (15A maximum) but the compressor on the Wolo horns I bought says could draw 18A. Have you had any issue with the DFRobot relays being beefy enough? Also, I wondered if you found the buzzer to be loud enough. I worry that being inside the box, it may be hard to hear on a windy day. Also, it does not appear that the buzzer needs a relay, right?
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