I have a 555 out put connected to a coil and i get the frequency i need. But now i need the 555 to power more coils. How should i connect the coils to keep the same frequency. In parallel or Series? The 555 will not directly power the coils. It will switch a Mosfet and that will provide the power for the coils. The 555 will have to work about 24/7. Can it?