Eric Surendranath Posted October 15, 2023 Report Share Posted October 15, 2023 So I am setting up something like a two team trivia buzzer, only using an LED in place of the buzzer. The goal is to have whichever button is pressed first light up it's corresponding LED and prevent the other LED from lighting up at the same time even if the second button is being pressed. I set up the steps/connections I think are correct, and would like help making sure before I start wiring and soldering. This is what I have: Components: Two Two-Terminal Buttons (Red and Green). Two Omron G5V-1-DC5 Relays. Two LEDs (Red and Green). One CR2032 Coin Cell Battery. Universal PCB (7x9 Double-Sided) Wiring and connections. Wiring Steps: Button Wiring: Connect Lead a (Red Button) to Coil1 (Omron G5V-1-DC5 Relay 1). Connect Lead a (Green Button) to Coil2 (Omron G5V-1-DC5 Relay 2). Connect Lead b (Common Connection) from both buttons to the positive terminal of the battery (Common). LED Wiring: 4. Connect Lead j (Negative Terminal of Red LED) to Ground (GND) on the PCB. Connect Lead k (Positive Terminal of Red LED) to NO1 (Normally Open) on Relay 1. Insert a 50-ohm current-limiting resistor in series with Lead k (Positive Terminal of Red LED), connecting one leg of the resistor to Lead k and the other leg to NO1 on Relay 1. Connect Lead l (Negative Terminal of Green LED) to Ground (GND) on the PCB. Connect Lead m (Positive Terminal of Green LED) to NO2 (Normally Open) on Relay 2. Relay Wiring: 10. Connect Common1 on Relay 1 to the positive terminal of the battery (Coin Cell Battery) to provide power for the Red LED. Connect Common2 on Relay 2 to the positive terminal of the battery (Coin Cell Battery) to provide power for the Green LED. Quote Link to comment Share on other sites More sharing options...
HarryA Posted October 15, 2023 Report Share Posted October 15, 2023 I do not see the connections to relay's NC contacts for each LED. The red LED most get its current through the NC contacts of the Green LED's relay. And the green LED must get its current through the NC contacts of the red LED's relay. Thus when one relay is active the other LED can not receive current through the the now open NC contacts. Quote Link to comment Share on other sites More sharing options...
Eric Surendranath Posted October 15, 2023 Author Report Share Posted October 15, 2023 So instead of the positive of each LED going to the NO terminal of their own relay, they would be wired to the NC terminal of the opposite relay? Quote Link to comment Share on other sites More sharing options...
Eric Surendranath Posted October 15, 2023 Author Report Share Posted October 15, 2023 Wait, but wouldn't the other relay then be able to activate by pressing the other button and consequently light up the other LED? Quote Link to comment Share on other sites More sharing options...
HarryA Posted October 16, 2023 Report Share Posted October 16, 2023 How about this? Without showing the resistors. Quote Link to comment Share on other sites More sharing options...
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