ED Domes and EDM Domes ED ED, the disc contact is a momentary tact switch with short travel and good tactile feedback. Direct mounting on a printed circuit board is possible. In that case, the dome must be actuated by a soft actuator of 3.0 mm (0.118) minimum diameter. The ED dome is available in various types of modules and is the main component of several switches presented in this catalog. Self-cleaning system: The contact is made on at least 3 points of the lower diaphragm, these 3 points of contacts are always different at each new switch action. During the switching movement, the upper disc slides on the lower diaphragm, ensuring the contact’s self-cleaning. EDM The EDM is available in 4 versions: EDM 450 AU EDM 650 AU EDM 450 AG EDM 650 AG The EDM Multi Dome Series was developed for low profile applications needing increased tactile response and high performance specifications. Applications range from aircraft instrument panels to radio keypads. This high performance dome switch combines our reliable ED contact system with added tactile domes for forces of 4.5N (450 grams) and 6.5N (650 grams). Construction Function Contact arrangement Distance between button Terminals Electrical data Switching power max. AC/DC Switching voltage max. AC/DC Switching current max. AC/DC Carrying current max. AC/DC Dielectric strength (50 Hz/1 Min.) Operating life with max. switching power Contact resistance Insulation resistance (100 V) Contact bounce Mechanical data Switching travel Operating force Further data Contact material ED Momentary 1 make contact = SPST 12.7 (0.500 ) PC pins or tabs Silver 6W 100 V 100 mA 250 mA 300 V 106 operations 10 mΩ 1011 Ω 100 µs Gold 3W 3W 100 V 100 V DC 50 mA 50 mA 250 mA 300 V 300 V 5 106 operations 15 mΩ 1011 Ω 100 µs Soldering by static bath 15 mΩ 1011 Ω 1ms ED 0.3 (0.012 ) Max. admissible 0.5 (0.02) 2.4N ± 25% (240 grams ± 25%) EDM 0.4 (0.0157 ) Max. admissible 0.5 (0.0197) 4.5N (450 grams) ±25% 6.5N (650 grams) ±25% Silver plated, Gold plated Ag (silver plated) Au (gold plated) -55°C to +85°C -55°C to + 85°C Thermoplastic Phosphor bronze 1.5 microns gold (G) Operating temperature – 25°C to + 70°C Storage temperature – 40°C to + 85°C Material housing contact base plating of contact area Climatic data Climatic category (days) EDM Momentary 1 make contact=SPST,NO 12.7 (0.500 ) centers, min. PC pins or tabs 10 for silver version 56 for gold version 255°C for 5 seconds Main features Gold (Au) or silver (Ag) contacts Two different operating forces Low profile Compact PWB spacing Proven application in avionics Ordering code: see next page. Dimensions are shown in mm (inch) Dimensions subject to change www.ittcannon.com A-36 ED Domes and EDM Domes Dimensional Drawings ED Domes 1.2 (0.0472) 12 (0.472) 11.36 (0.447) 12.7 10.35 (0.5) (0.407) 0.8 (0.0315) 5.7 (0.224) 11.3 (0.445) Switch action principal The disc contact is essentially made of two separate conductive domes diaphragms separated by an insulated material. The upper diaphragm is shaped so that under pressure it collapses suddenly and establishes contact with the lower diaphragm. Upper diaphragm Pressure Lower diaphragm SWITCH IN RESTING POSITION Insulating washer Circular contact area SWITCH IN ACTIVE POSITION Ordering code Example: 1 2 3 4 1 ED 2 S 3 SC 4 0 Designation: ED / EDM450 / EDM650 Contact material: S = silver, G = gold Contacts: AC = with PC pins, SC = with tabs Sealing: 0 = flux sealed, 1 = totally sealed Dimensions are shown in mm (inch) Dimensions subject to change www.ittcannon.com A-37