Source Voltage - chosen to be 12 VDC due to safety and remote
Resistor Power - some standard power sizes are 2, 1, 3/4, 1/2, 1/4,
and 1/8 watt. The 1/2 and possibly the 1/4 watt are best suited for use in this
Number of Resistors - 4 to 6 is a good number to work with around
1.25-inch barrel eyepieces. The necessary number will vary with your
Calculated Resistance - this is the exact resistance calculated that
would be driven to the maximum Resistor Power at Source Voltage specified. The
next higher stardard size should be used. Standard sizes readily available are
10, 15, 22, 33, 47, 68, 82, 100, 150, 180, 220, 270, 330,390, 470 ohms, etc.
Precision resistors will get you closer to the calculated value but are also
Volts Per Resistor - in a series circuit, with each resistance the
same, equal voltage is dropped across each resistance.
Loop Amperage - in a series circuit, the same current must flow
through all component resistances in the circuit.
Total Loop Power - this is the total heating power of the loop. For
best performance this value should fall at 2-3 watts, which should be sufficient
to keep optics clear.