To have a more reliable power source I want to use a 9V power supply, instead of the battery. So I cut the wires of a 9V power supply (I bought for my Arduino), I connected them to the voltage regulator and plugged it in.
But when I tried to send a message over my 433MHz transmitter but the relay did not turn on. Then, I unplugged the power supply and connected the battery to the voltage regulator resent the signal and the relay turned on. I used a multimeter to make sure the power supply was working and the voltage and amperage where pretty much the same (arround 9V and 2.5 amps).
Why does not the power supply work?
Power supply label
AC/DC ADAPTER Model No: MTR-910 Input: 100-240V ~ 50/60Hz 0.2A Output: 9V DC 1A
Remeber that it worked with the battery, it doesn't work with the power supply.