@Mallard4468 posted:I've used similar items for other purposes, such as adding smoke units. One question - how do you adjust the output voltage? The units I use have a small adjustment screw; I didn't see one in the pictures.
That is NOT a voltage regulator, just a rectifier and capacitor filter.
The voltage out is directly tied to voltage in with no adjustment. The output voltage difference is easily explained by AC RMS input VS Peak rectified voltage output- especially under light to no load conditions. RMS is less than peak voltage- it's the average on the AC waveform. Again under no or very light load, the capacitor will charge to at or near peak voltage hence the difference- 18V AC RMC VS 24V DC Peak voltage. I might add- this is how you can blow up electronics- hitting them with a high peak voltage- higher than they are rated for.
If you need a lower voltage, you need 3-4 functions in the circuit- rectify AC to DC, then bulk filter capacitor to get pure high voltage DC, then regulate down the voltage, and possibly more final filter (caps).
As an example- way more steps and components
