I forgot about how resistance adds in parallel versus series. I can convert the parallel board into series by making three cuts and moving one of the power connections.
The total resistance of the parallel circuit is 1.2 ohms and there are four resistors in parallel. Solving for the resistance of one resistor:
1.2 ohms = 1 / (1/x + 1/x + 1/x + 1/x)
x = 3.33 ohms
Resistance adds together in series, so the resulting series circuit has 13.32 ohms of resistance. I=V/R and P=IV, so at 12v this is a 0.9A 10.8W circuit, and at 24v this is a 1.8A 43.2W circuit. The original 12v circuit was 120W, so both are worse than just using 12v in parallel.
![69aYG1u.png]( "69aYG1u.png")
What about making an MK2b board out of an MK1. That is, two pairs of series resistors. Resistance in each circuit is 6.66 ohms. At 12v this is two 1.8A 21.6W circuits = 3.6A 43.2W. At 24v this is two 3.6A 86.5W circuits = 7.2A 173W.
![dxZCXN8.png]( "dxZCXN8.png")
Getting 173 Watts out of 7.2 Amps at 24 Volts seems better than 120 Watts from 10 Amps at 12 Volts.
The total resistance of the parallel circuit is 1.2 ohms and there are four resistors in parallel. Solving for the resistance of one resistor:
1.2 ohms = 1 / (1/x + 1/x + 1/x + 1/x)
x = 3.33 ohms
Resistance adds together in series, so the resulting series circuit has 13.32 ohms of resistance. I=V/R and P=IV, so at 12v this is a 0.9A 10.8W circuit, and at 24v this is a 1.8A 43.2W circuit. The original 12v circuit was 120W, so both are worse than just using 12v in parallel.
What about making an MK2b board out of an MK1. That is, two pairs of series resistors. Resistance in each circuit is 6.66 ohms. At 12v this is two 1.8A 21.6W circuits = 3.6A 43.2W. At 24v this is two 3.6A 86.5W circuits = 7.2A 173W.
Getting 173 Watts out of 7.2 Amps at 24 Volts seems better than 120 Watts from 10 Amps at 12 Volts.