Relay module effecting Arduino - General Electronics - Arduino Forum

Dear All, I have a problem I am stuck with it for over a month. I have an Arduino mega connected to 4channel relay module as suggested in the diagram below. I am connected RTC and lcd screen to arduino as well. I am using 2 separate power adapters one for arduino and one for relays. JD-VCC jumper is removed so relays should be isolated from arduino. Relays are connected to 4 x 220v alarm bells. Run for 3 seconds every 45 minutes. Problem: Sometime when the alarm turn off, the LCD screen

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