I have a Alarm System Pro (v1.7). The board’s two 5V connections power a 4-channel relay board, and 3 water sensor boards. See the attach wiring diagram.
If I use OUT 1 to switch on Relay 1, it comes on and works fine.
If I use OUT 2 to switch on Relay 2, it comes on and works fine.
If I switch on both OUT 1 & OUT 2, both relays come on… and then after about 2 seconds, the 2 relays and 3 sensor boards all “blink” off and on about once per second continuously.
If I turn off either OUT 1 or OUT 2, the blinking stops and everything is fine again.
To trouble shoot this problem, I first moved the OUT 1 & 2 connections to relays 3 and 4 (which are not connected to anything) to test the relays, but that didn’t change anything. Then I disconnected the 3 water sensor boards and everything works! Further testing shows that I can connect 2 water sensor boards running along with 2 relays. Adding the 3rd water sensor board back in reproduces the problem.
So, it seems to me that I am overloading the 5V power output circuit on the Alarm System Pro boards and it resets itself (due to heat or something??), then continues until I reduce the load (by turning off one relay).
My questions about this issue:
- Does this seem like an overloaded (not enough current) 5V power output issue on the Pro board?
- Is this a problem with the Pro board, or just the way it works?
- I’m powering the board with a 12V 2.5 amp power adapter. Would getting a power adapter with more current (12V 4 amps) resolve this problem?
- My issue was resolved by using a separate 5V power adapter for the water sensor boards (leaving the Pro board to only power the two 5V relays). If a second power adapter was not available, could I use a 12V to 5V power converter connected to AUX to power the 3 sensor boards, or would this just shift the problem to the 12V rail on the Pro board.
Thank you for any insights into my little issue! Although I have resolved the problem, I’m just trying to understand the hardware and its limitations.