When do you need a solid state relay? And how do you choose - when faced with a catalogue of products that runs to 126 pages?

EL.CO. was formed in 1986, and since then has continued to develop its range of solid state relays (or static relays). The newest introductions to the range include the SSR01DH / SSR02DH / SSR05DH series.

These latest solid state relays (SSRs) combine a high switching speed and low control power with a 3,750V input-output insulation, and can be stored at temperatures from  -40 to 100°C. Operating temperature is -30/+80°C.

They’re yet another addition to an incredibly impressive range, which you can see here.http://www.nexuscomponents.co.uk/Manufacturers/ELCO
At Nexus, we have the technical knowledge to make sure you get the right SSR for your needs - and when another solution might be the right one. Because no single SSR perfect for all applications - hence the need for such a big catalogue of products.

Quite simply, SSRs are an alternative to using a regular switch when you want to turn a circuit on or off. As well as being smaller and less expensive than a switch, the SSR has no moving parts. It can therefore work much quicker, and it lasts longer than a switch would - because when parts can move, they can also wear out.
First introduced in the 1960s, SSRs were the next generation after the electromechanical relay. Whilst an electromechanical relay is robust and able to be adapted to a variety of tasks,  it tends to take up more room. An electromechanical relay can take 5-15ms to switch - far too slow for some applications.
The wires of an SSR are smaller and of a higher gauge than a switch, allowing the units to be much smaller.  They help increase safety since you're dealing with a lesser voltage and amperage - making them a great choice for much higher voltages, when a regular switch might burn out under high current. They can be designed to turn on with a control current as low as 1 milliAmp, although 5 to 15 milliAmps is used more often.

So SSRs are faster, smaller and have a longer lifetime than a mechanical relay. Used in light bulbs and fixtures, cars, heaters, computers and power supplies, they have many advantages. No recoil, no mechanical wear, reliability, reduced response time, and shock resistance - the solid state relay has an impressive list of attributes. Not least a complete lack of sparking - vital in explosive environments.

They can operate for millions of cycles with no loss of function. As they switch silently, they are at huge advantage in power cabinets containing many relays, when noise can really mount. And they can be used in moist and dirty environments.

Their advantages over electromechanical relays can be really felt in thermostats,  high-speed switching applications such as heating circuits, and any use where there will be frequent on-off cycling (SSRs have no contact bounce).

However SSRs can be prone to drooping from 1 to 1,5V; and are only compatible with  A.C. or D.C. exit output. They can also be resistant to transient voltage. They need to be arranged correctly - well ventilated, and not arranged in rows on top of each other.

All EL.CO.’s solid state relays come with a snubber filter, protecting them from spikes caused by an excessive speed of the output voltage. In some environments - such as heavy industry - additional protection can be added, and fast-reacting fuses may be needed. Again, Nexus has the expertise to advise to make sure your solution is the right one for your needs.

If you’re looking for SSRs, you can find our EL.CO. range here -

http://www.nexuscomponents.co.uk/Manufacturers/Products/ELCO