SSR?

Thomas

What exactly IS an SSR(solid state relay) anyway. As far as I can tell NO ONE could ever need one. Maybe the inside of a computer would have the dynamics nessisary to require such a device. 3-32 voltsDC controlling AC only contactor. AC only because it only allows current thru at a point in its sine either low or node, and only if the controlling DC is on. For some reason I have two of these now and have absolutely no use for them at all. Can any one tell me where they came from, what purpose did/do they fill?

Vic

Re: SSR?

Thomas!

Welcome to the internet.

Google IS your friend! Googled, " AC SSR " and got this very useful link:
http://en.wikipedia.org/wiki/Solid_state_relay

The Wiki is also your friend.

Some of us have mused that your ever-so-frequent questions are really a pleading for attention. I dunno. Sometimes, quiet contemplation and sloitary research, as we used to do as kids in the Library are very useful habits. We can pose questons to ourselves, research. wonder, do more research and answer many of our own questions.

We all sometimes take the lazy way out, and ask others to take the time to 'splain everything to us, but, good study habits are rewarding.

Am I being too rough on you? Thanks, Vic

TnAndy

Re: SSR?

Here's a feature of this forum software I discovered about 30 seconds ago:

http://forum.solar-electric.com/profile.php?do=ignorelist

Thomas

Re: SSR?

I was researching everything on the internet untill I began troubleshooting my Air-X generator, I became discouraged with the seemingly contradictory articles/essays about 3 phase electrical generation. This forum has been on the whole helpful, and dispite some negative feedback, I think joining has been positive. Back to the ssr, wikki link didn't provide a history for me that I was looking for, what purpose a DC controlled AC switch? Softstart appliances or something in a circuitboard? Being too hard on me? that depends on which of my hardships you take credit for!!hahaha Googling on for ssr history thanks.

Joe_B

Re: SSR?

Thomas,

You said "what purpose a DC controlled AC switch?" Think about it, with such a device you would be able to control a big AC load with a small DC voltage. Simple huh?

At this point I think you either got a nasty shock or this comment, now deleted, is an attack on the poster and i must warn you not to do this again, niel.

By the way, it is spelled Logarithm

Now I must restrain myself before I get myself banned.

Vic

Re: SSR?

Thomas,

Regarding the "history", at the bottom of the Wiki link in my first post, LOOK at the bottom -- 'External links', is: Solid State Relay Inventor and Early Patents link:

http://en.wikipedia.org/wiki/Roy_Mankovitz#Engineering_Career

In that link, under 'Engineering Career', the para beginninng, "in 1968 ", you will READ about the invention. The "FOOTNOTES" are rich with INFORMATION, for YOU to STUDY. This should be rich and rewarding for YOU to READ.

Have fun with your STUDY! your friend, Vic

Cariboocoot

Re: SSR?

Guys, you're making it hard on those of us who wear the big 'M'. :roll:

solarvic

Re: SSR?

Good to see ya back! Cariboocoot, Mark

Cariboocoot

Re: SSR?

solarvic wrote: »

Good to see ya back! Cariboocoot, Mark

Thanks, Vic. Regrettably it is not yet permanent.

Thomas

Re: SSR?

Vic-thank you for the guidance, if it doesn't jump out and bite, sometimes I don,t find it. I did not recall reading about the inventor in the link SSR w/wikki., shoulda looked harder. Ever see the movie real genius? sounds like Gov. motivation invention. I applied to Teledyne in Hudson, NH, I went to High school there. They weren't hiring.
M=13th number of the alpabet...your all evil.
Large voltage controll with small voltage is what relays are all about, isn't it?
What is up with zero switching?
(oh, gov. research released..it was a part of a rocket that engineers can use in furnaces etc..)
caraboocoot, no open season, can be found riding raindeer...

Vic

Re: SSR?

Coot ... OH!!

Thomas, From what you have posted previously regarding SSRs, Would like to make sure that you understand, roughly how the SSR works and is applied.

An AC SSR is is a Solid State Realy. There are NO moving parts, just a specialized semiconductor switching device(s) that do the job, from a low-current DC Control voltage. A very large current can be controlled with a very small current. These AC SSRs are useful in replacing Contactors and other power relays. There are no arcing contacts, and the switching occurrs at the lowest voltage of the input sine wave of the AC power. This is much more gentle on the thing receiving the power, and can help limit the inrush current etc.

Am done, just trying to make that distinction. Vic

Thomas

Re: SSR?

Vic-yeah I understand relays pretty good. I do not like these ssrs, they run too hot. I did find some dc/dc ssrs for my purpose if the contactor I selected does not work. (for use with a Gavazzi line regulation switch eugc724)
It seems like a trade off, some safety, reduced spark and start/inrush current, though man they get hot. not warm, hot so you cant even touch or handle them. that is scary, and normal?
Does Butte J.C. ring a bell to you in Northern Cali?

mike95490

Re: SSR?

After you change out a couple contactors/relays, the SSR's begin to look more attractive. Even more so, depending on how annoying the failed relay affects you.

Thomas

Re: SSR?

I have allready ruined a contactor, though I believe it was really a starting soleniod only, mis advertised. The ssr does have a real neat attribute. when it turns off, it stays off untill the relay in energised and the current is right, eliminating the on/off end of the day cycling, draining too much from the batteries and not displacing the grid use enough to justify the continued effort. The one I am waiting for is a 100A electric car contactor 12v controll. If it fails I may try one of the dc/dc ssrs and just set a re-connect point and let the inverter turn istelf off, and stay off.with the ssr.

Joe_B

Re: SSR?

Thomas, if you SSR is getting too hot to touch, it will soon fail, I hope you have it mounted on a properly engineered heatsink.

How much current are you switching with this device?

This link may help you understand...

http://www.power-io.com/library/appnotes/heatsink-info.htm

Thomas

Re: SSR?

I do not think I am opting for a ssr at this point, I don't have any children I am aware of so I can get the ones with moving parts.
I am only switching about 15A max in the winter and maybee 20A-25A in the summertime.
The ssr is light switched for total insulation/separtaion from controlled circuit, I dunno about no moving parts, the one I tried clicked like coil operated relays.
getting back to basics, automatic on/off @ good/bad volt level...always difficult to take a step back...

Thomas

Re: SSR?

the heat sink is designed for a 40A SSR, I am going to adapt it to the contactor if nessisary.

Joe_B

Re: SSR?

A mechanical contactor will not require a heatsink.

Thomas

Re: SSR?

then... I will remove it.