Back EMF – When a flipper turns off, the withdrawal of the plunger from the flipper coil turns it into an electric generator. This power is often called ‘Back EMF’ and is shorted out by the coil diode. A better term is ‘inductor current’. The phrase ‘inductive kick’ is also used. This occurs only with DC circuits.
Crank Assembly – The is the part that moves on a flipper and usually has several subcomponents. These include the plunger, the (crank) link, and lever arm.
Coil – A wire coil that generates the magnetic field that pulls in the plunger to fire the flipper. Most coils have 3 wire connections.
Coil Stop – The part at the ‘end’ of the coil that the plunger slams against with each flip.
DE/Sega/Stern – Data East was a pinball manufacturer, purchased by Sega, which was purchased by the current day Stern manufacturing. There are common elements of machines by all three manufacturers.
Diode – Conducts current in one direction. Must be on all SS flipper coils (and DC EM pinball machines) to prevent the back EMF (inductor current) from frying the circuits.
EOS Switch – End of Stroke Switch. Switches the flipper coil from high power (shoot) to low power (hold). On all flippers from the 1950’s to present day.
EM – Electro mechanical pinball machine. Controlled by relays and spinning reels.
Flipper Bat – The flipper part above the playfield that hits the pinball.
Flipper Stop – Same as the coil stop.
Fliptronics – Catchy name coined by Williams about 1992. Flippers are controlled by the computer. Only low power flows through the switches and they no longer burn. Flippers can operate well even if EOS Switches break off. DE/Sega/Stern have a similar system introduced about 1990.
Inductive Current – Also known as ‘inductive kick’. This is the technically correct term used for ‘Back EMF’.
Link – Part of the crank assembly that connects the plunger to the lever arm. This is the part that usually wears out.
Plunger – This is the cylinder that ‘plunges’ into the coil when the flipper is activated. The end of the plunger sometimes mushrooms from hitting the coil stop.
NO Switch – NO stands for Normally Open. It is a switch that, at rest when the system is off, the switch does not make contact. It is on the ‘off’ position. It is the opposite of NC.
NC Switch – NC stands for Normally Closed. It is a switch that, at rest when the system is off, the switch contacts touch. It is on the ‘on’ position. It is the opposite of NO.
Snubber Diode – This is a technically more descriptive term for the diode that is across the coil in SS games.
Sold State Flippers – Name used by DE/Sega/Stern to describe flippers controlled by the computer. Only low power flows through the switches and they no longer burn. Flippers operate well even if EOS Switch breaks off. Frequently inaccurately called ‘Fliptronics’ which is a Williams system.
SS – Solid State. Pinball machine controlled by computers. Electric displays.
WPC – The ‘system’ developed by Williams used on all Bally/Williams pinball machines from 1990 until Pinball 2000 was introduced. It is short for ‘Williams Pinball Controller’. There are three different generations: WPC89, WPC-S and WPC95. Within WPC89, there are subsets of: WPC89 Alphanumeric, WPC89 Dot Matrix, WPC89 Fliptronics and WPC89 DCS.