Quoted from PinMonk:Probably dual, but doesn't matter. Even a dedicated lower power hold-only circuit will increase temps over time if driven by 1ms or longer duty cycles. Microsecond duty cycles are the key to temp stability in hold, regardless of single or dual wound coils.
what?
Dual-wound coils don't use duty-cycling.
On activation, both the high current (fewer windings) and low current (many windings) coils are energized, providing a strong initial flip. As the flipper reaches the end of it's stroke, the crankshaft pawl opens the EOS switch and either physically cuts power to the high-current coil, or tells the computer to cut power, leaving only the low current, high winding coil energized. This is enough to keep the flipper up but not enough current to overheat. The coil should not increase in temperature even after long holds if the windings are correct.
HWN uses dual-wound coils but after dealing with ridiculous amounts of heat and fade, even with fans, I suspect they are not being driven properly in current code.