Replacing a sound module's LCD/EL backlit display with a LCD/LED backlit display
Your LCD's LED typically accepts 4.2~4.6V. It should be self regulating, so no further resistor needed. You have 11V or 5V available. Below are the three options available. First is use a Adjustable regulator from 11V. The Second is use a fixed 5V regulator and then a regular silicon Diode (1n4001 or similar) to bring it down another ~0.7V. In either mode, the regulator wastes 1 Watt of heat, a heatsink might be recommended (attach the regulator to the module's metal casing is one method).

Or as mention, tap off the already existing 5V regulator, and just throw on the diode. 0.160A is not exactly a large load, it should be fine.







simulate this circuit &ndash; Schematic created using CircuitLab