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

Relay module effecting Arduino - General Electronics - Arduino Forum

Relay switching unexpectedly. EMI problem? - General Electronics - Arduino Forum

Getting a relay to work - Project Guidance - Arduino Forum

Controlling seven relays one by one - Project Guidance - Arduino Forum

How to View I/O Status on the Arduino Opta - Industrial Automation and Control - Electronic Component and Engineering Solution Forum - TechForum │ Digi-Key

HLK-LD2410C Human Motion/Presence Detection Radar Sensor (HCSENS0051)

Arduino 4 Relay Shield - 4 relays 30V / 2A Botland - Robotic Shop

Using relay - General Electronics - Arduino Forum

SOLVED: Solenoid woes - causing arduino to freeze up when used via relay (Help!) - General Electronics - Arduino Forum

5V relay not working with nodeMCU - General Electronics - Arduino Forum