DC power supply dummy load

 In order to test my DC supplies I have built a DC dummy load.  Assuming the load voltage is 13.7 V then a 27 ohm resistor will draw about 0.5A and will dissipate about 7W.  My dummy load jig consists of six 27 ohm 10W resistors that can be individually switched into or out of the load.  

Aside from no switches on (zero load current) the load current can be varied from 0.5A to 3A in 0.5A increments. The schematic is shown below. 

I soldered the circuit together as shown in the photo.  At some later time I'll 3D print a cabinet for it. 

I bought 10 switches and 10 resistors off of Amazon for a cost of about $15.  I'll design and build an electronic load later.