I created a circuit running on 5V DC, with an

chip on it, to turn a 2-channel relay module on and off and receive signals with a 433MHz receiver.

As a power source I use a 9V battery which is connected to a 7805 voltage regulator to get 5V.

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 the same.

Why does not the power supply work?

Power supply label

Model No: MTR-910
Input: 100-240V ~ 50/60Hz 0.2A
Output: 9V DC 1A