Low voltage currents are in sometimes AC, and or DC.
In AC Power[]
Sometimes, in ac power its listed on transformers or power adapters or power supplies. At 24VAC, it can power a fire alarm control panel, or a HVAC Control board.
24VAC Transformer output (120VAC to 24VAC)
For 12VAC Transformer[]
At a 12vac transformer output can power lanscaping lighting, panels, and any other thing it can do.
12VAC transformer output (120VAC/110VAC to 12VAC)
DC Voltage Output Transformers[]
In a DC voltage output transformer, it can put out of voltages like 3VDC, 4.5VDC, 5VDC, 5.8VDC, 6VDC, 8VDC, 9VDC, 10VDC 11.5VDC, 12VDC, and 24VDC.
6VDC output transformer (110VAC to 6VDC)