I am trying to get ±5V using voltage regulator L7805 and L7905.
The datasheet says to use AC source as input and transformer, but I am not really familiar with transformers, and I don't know if I can handle 110V AC as a source.
So I came across YouTube clip, creating ±5V with DC input.
Figure 1: Circuit Diagram
Then I also learned that size of capacitors are enough as long as they are more than what datasheet requires, from searching through StackExchange How do I decide what capacitor to use in a circuit?
Figure 2: Datasheet from L78xx and L79xx
I choose 220uF, 50V. This was the biggest I have right now.
I used DC 12V as an input.
I tested L7805 and L7905 individually, to check whether they are producing voltage +5V and -5V, respectively.
Figure 4: Individual regulator test
From voltmeter reading, I get that individual operation is fine.
Then I tried the whole circuit diagram (Figure 1), and I don't get the voltage properly.
Figure 5: Whole circuit test
As can be observed from Figure 5, L7905 produce voltage of -5, but L7805 doesn't. I replaced L7805 with other L7805 to see if that L7805 was damaged, but it wasn't.
I searched more on Stack Exchange, and found one, Incorrect Output From 7805 but it doesn't solve my problem.
Then I found an website, that suggests I need more input voltage.
I changed to DC adapter of 18.75V with 3.15A as an input, however, it doesn't solve my problem either.
Was it had to do with wrong(?) circuit diagram (Figure 1) from the very beginning?