Solid state relays can be supplied with either a zero voltage turn on feature or an instantaneous turn on. Depending on the application the designer will decide which is best for his end use. With a modified version of the opto-transistor circuit of Fig 2 a normally closed solid state relay can be designed. Solid state relays can be either ac or dc voltage controlled, for ac control the ac signal is rectified and filtered to provide dc to the opto-transistor or opto-triac LED. Obviously the ac control versions can also be dc controlled, just one half of the rectifier is used.
There are a number of conditions that must be considered when selecting the appropriate motor controller to Start/Stop modern electrical AC motors and associated machinery. These conditions include frequency of starting and stopping, whether light or heavy duty starting, required frequency of reversal, smooth starting/stopping requirements, etc. Crydom offers a wide range AC single phase and 3 phase solid state relays and contactors rated up to 25 HP @ 600 VAC which are suitable for literally hundreds of AC output Motion Control applications including:
Industrial OEMs: Plastic Machinery ,packaging and material handing equpment , metal /wood/glass working machinery ,valves and pumps.
Energy and infrastructure: wind turbines ,solar energy equpment,mining machinary oil and gas.
Food and Beverage: Bakery ovens ,dough dividers ,mixers
Medical: Sterilizers,autoclaves ,X-ray equpment ,
Building equpment: HVAC and R Compressors ,variable air volume system.
Crydom’s DC Motion Control products utilize advanced DC switching technology with low power dissipation power FETs coupled with high performance optical coupling which provides reliable high power DC switching up to 160 Amp and operating voltages up to 300 VDC. Furthermore, Crydom Motion Control products offer the latest in DC Solid State Power control by virtue of Crydom’s advanced high speed DC switching circuit for on/off or PWM control up to 1 KHz. Although there are a huge number of DC motion control applications for Solid State Relays and Contactors, most can be included into the following categories:
Transportation: Trains, Railway Vehicles, Specialty Vehicles, Street Cleaners, Snow Groomers, Construction Machines
Industrial OEMS:Material Handling Equipment, Cranes, Pallet Trucks, Industrial Valves
Commercial OEMS:Payment Systems, Advertising Displays, Floor Cleaning Equipment,
Aerospace and defense: Land Vehicles, Defense Armored, Tanks
Building Equipment:Access Control, Highway Toll Systems