Here’s a straightforward way to build your own “Runtz” type voltage reducers so that you can use your 6 volt gauges on your 12 volt system. The regulator is based on the LM7806 integrated circuit, which is able to reduce voltage while maintaining a constant current. Use one regulator for each gauge; this allows you to keep each circuit separate which is useful for sorting any troubles you might have. While it is possible to use one regulator for all gauges using a power transistor, it has a bigger footprint and produces more heat, requiring it to be carefully mounted … Continue reading How to Build a Voltage Regulator for $3