Power Circuitry

Here is a quick example of the changes in the power circuitry on a Digital View LCD controller board. The image below shows the ALR-1920 and its successor model, the ALT-1920. These boards are functionally very similar and they are the same size thus making the move to the new model as easy as possible.

The area outlined in red shows the part of the circuitry devoted to the power supply, taking the 12v or 24v DC input and converting it to the other voltages required. The ALR-1920 is on the left, the ALR-1920 is on the right:

A short comparison table:

ALR-1920ALT-1920
Input voltage12V/24V12V/24V
Switching frequency260kHz500kHz
Power inductor4A4.5A
CapacitorsE-capCeramic
Area for power circuitA~50% of A

A benefit of the ceramic capacitor is its longer operating lifetime, especially in elevated temperatures, compared to an electrolytic capacitor.