Just apply your 12VAC across the "AC" tabs and out comes the 12VDC on the positive "
+" and the negative "
-" tabs.
View attachment 168825
A bridge rectifier isn't truly DC.... it needs some electrolytic capacitors on the output.
It performs no regulation, only rectifying.
and you beat me to it
.
Example of a power supply using such a bridge rectifier, the capacitor is in parallel.
Here's the AC waveform of 12v RMS (16.97 peak-peak).
Frequency is different for ease of viewing the graph.
If you put that through a bridge rectifier it just allows the positive half of the sinewave to come through. The voltage between the two output terminals is still fluctuating between 0v and peak voltage.
With a capacitor in parallel to your full-bridge rectifier, the output is smoothed a lot more but will still experience some voltage ripple.
Secondary of your AC transformer current is roughly 1.8 times current on the DC output (1.8 * I_dc.)
An IR spot light should handle some ripple fine..... more sensitive loads should have better regulation. You can buy buck-stepdown modules or linear voltage regulators for this.
Enough with equations..... LOL.