It serves the same function as an electromechanical relay but has no moving parts and therefore results in a longer operational lifetime. Most systems using solid state relays or SSRs have a light emitting diode or use the light from a LED source.
SSRs use a low power electrical signal to generate an optical semiconductor signal typically with an opto-isolator or octocoupler that transmits and energizes the output signal.
Solid state relay vs mechanical. Electromechanical relays create electromagnetic noise because of contact arcing and can create interference in the power lines. Like all relays solid-state relays should be protected from inductive loads using external components. Light from the encapsulated LED actuates the photo-sensitive MOSFET and allows current to flow through it.
This will reduce the damage to the silicon used in the switching. However solid state relays are superior to electromechanical in most comparative categories. Unlike EMRs SSRs have no moving parts that will wear out and therefore no contact bounce issues.
SSRs consist of a sensor which responds to an appropriate input control signal a solid-state. Since the genesis of solid-state relays some decades ago the argument about which is better solid-state relays SSRs or electromechanical relays EMRs has raged on. A solid-state relay uses semiconductor devices instead of mechanical.
They are selected for quiet operation because they do not make noise when the output contacts change states. Solid-state relays operate silently and produce little electrical interference. One of the significant advantages of a solid state relay over an electromechanical relay is its response time ability to turn on and turn off.
The advantages of solid-state relays include the following. One can argue that something complex is not necessarily better than a comparable simpler product that does the same task. In this video I describe the similarities and differences between two of those options.
When it comes to switching things on and off there are many options. Electromechanical relays has a life time of few million mechanical switching. Due to an optoisolator rather than moving parts the life span of the SSR is often longer than the EMRs.
Electromechanical relays are safer because they tend to fail while the circuit is open meaning there is no current flow. No risk of voltage surges in solid-state relays. The general answer is.
SSRs are a faster alternative to electromechanical relays because their switching time is dependent on the time required to power the LED on and off - approximately 1 ms and 05 ms respectively. A solid state relay SSR is an electronic switching device that switches on or off when an external voltage AC or DC is applied across its control terminals. The solid-state relay input energizes an internally constructed LED with an appropriate current-limiting resistor integrated inside.
An EMR may be able to respond hundreds of times per minute but an SSR is capable of switching thousands of times per minute with no chattering or bounce. Solid-state relays can have a much higher cycle frequency over mechanical relays so turning a high-power device on and off frequently is best handled by a solid-state solution. The SSR is able to switch ON and OFF much faster than a mechanical relays armature can move.
The mechanical relay uses a coil of wire generating a magnetic field using the principle of inductance. SSR lasts longer than electromechanical relays. There is less risk of electric shock working around a failed EMR versus a failed SSR.
Solid State Relays These relays perform the same function but differ from mechanical relays because they have no moving parts. On the other hand solid state relays tend to fail while the circuit is closed meaning that a current is flowing unimpeded. Solid-state relays seem to have an infinite lifespan when working with resistive loads provided the load is properly sized for the solid state-relay.
Since the introduction of solid-state relays some decades ago the debate over which is better solid-state relays SSRs or electromechanical relays EMRs has gone on. The response time of the solid state relay is much lower than that of the mechanical relay and the control power of the SSR relay is also lower than that of the EMR relay which makes the EMR not applicable to equipment that requires short response time and low control power. Many electronic designs can take advantage of the improved performance of solid-state relays SSRs relative to that of electro-mechanical relays EMRs that perform the same circuit function.
The answer is neither as each relay type has positive and negative aspects. The magnetic field attracts a swinging arm to engage the contacts. Solid state relays are semiconductor devices that use light rather than magnetism to actuate switches.
But if you factor in specific application requirements clear winners emerge. Electromechanical relays are a relatively old technology that use a simple mechanical design approach whereas solid state relays are much newer and advancedand yes more complex. Solid State Relay SSR.
