Solid State Relay (SSR) and Contactor

SSR being a superior replacement for Electromagnetic Relays and Contactors

About

Introduction

Using an SSR allows for control (e.g., from a microprocessor) over a high-power signal (e.g., switching of AC and DC loads) while isolating the logic part of a circuitry from high-power signals. Right now typically electro magnetic relays (EMR) are being used which provide isolation via a coil based electromagentic field clasing or opening a contact at the secondary side of a circuitry. EMRs do have mechanical moving parts built-in exposed to aging and arcing and therefore are limited in reliablity and fast switching. SSRs do overcome these shortcomings.

Fields of application

Digital  switching of high voltage or high load currents is required in industrial automation systems for e.g. switching ON/OFF motors, valves, pumps, fans, contactors, or brakes. In medical or vehicle applications this functionality is of interest as well.  

SSR- what is it?

SSR as  a combination of an galvanic isolator integrated driver (Infineon "iSSI")  plus a power switch (Infineon OPTIMOS TM/COOLMOS TM or IGBT) provides flexibility to address different kinds and magnitudes of load currents.

SSR just provides more

Infineon "iSSI" family provides diagnostic and protection features such as for overcurrent and with Miller Clamping. Temperature of the corresponding power switch  may be monitored as well. Form factor of an SSR may be chosen as small as with EMR. 

Simple to apply

No supply power is needed at the secondary side of the galvanic isolator to have SSR operating. 

Introduction

Using an SSR allows for control (e.g., from a microprocessor) over a high-power signal (e.g., switching of AC and DC loads) while isolating the logic part of a circuitry from high-power signals. Right now typically electro magnetic relays (EMR) are being used which provide isolation via a coil based electromagentic field clasing or opening a contact at the secondary side of a circuitry. EMRs do have mechanical moving parts built-in exposed to aging and arcing and therefore are limited in reliablity and fast switching. SSRs do overcome these shortcomings.

Fields of application

Digital  switching of high voltage or high load currents is required in industrial automation systems for e.g. switching ON/OFF motors, valves, pumps, fans, contactors, or brakes. In medical or vehicle applications this functionality is of interest as well.  

SSR- what is it?

SSR as  a combination of an galvanic isolator integrated driver (Infineon "iSSI")  plus a power switch (Infineon OPTIMOS TM/COOLMOS TM or IGBT) provides flexibility to address different kinds and magnitudes of load currents.

SSR just provides more

Infineon "iSSI" family provides diagnostic and protection features such as for overcurrent and with Miller Clamping. Temperature of the corresponding power switch  may be monitored as well. Form factor of an SSR may be chosen as small as with EMR. 

Simple to apply

No supply power is needed at the secondary side of the galvanic isolator to have SSR operating. 

Documents

Documents

Design resources

Partner

{ "ctalist":[ ] }