1 31 32 33 34 35 Next 520 Replies Latest reply on Jun 17, 2020 2:42 AM by devesh_rai Go to original post
      • 510. Re: Have a question about solid state relays and their applications? Ask me!
        colinkam

        Hi Pete,

         

        Lots of great questions and answers here. I apologize if this has been asked here before but does best practices consider an SSR sufficient shutoff to use as a main power switch? Do I need a switch controlling a contactor ahead of my SSR as a main shut off? Also, I have seen a phase angle SSR that adjusts power. Are there any special things to know about using one? I am not even sure what the actual name is for them. I have made zero crossing detectors and am familiar with how a phase angle SSR would work.

         

        TIA

        • 511. Re: Have a question about solid state relays and their applications? Ask me!
          wkendrick

          Hi,

           

          I am using a  CKM0630CKM0630 to switch on and off+58V to a circuit The+58V power is attached to the load on the relay and the load connection goes to a diode which is forward biased to pass the current to the circuit On the other side of the diode is a connection to an auxiliary power source that can be as high as+61V so the diode blocks this source from feeding back into the relay I have had one relay fail such that the load is always on or closed The led on the control line will operate correctly with the switching on and off of the control signal I do not have a fly-back diode across the load of the relay because I am not driving an inductive load What can cause the relay to fail like this in this situation and how can it be avoided

           

          Thanks.

          • 512. Re: Have a question about solid state relays and their applications? Ask me!
            cowabunga

            Hi Pete and all,

             

            I'm curious what DC applications would benefit the most from the use of an SCR SSR. It seems like the characteristics of latching on after gate signal, and then shutting off if drain current falls to zero, would be useful for some applications. Possibly in scenarios where continuous gate drive is unreliable, or when a load switch is only desired at initial turn-on, etc..... but I can't think of any applications offhand. I was told that SCR's are generally more affordable on a $$/amp basis, but I didn't see any products listed online.

             

            Thanks!

            • 513. Re: Have a question about solid state relays and their applications? Ask me!
              chris.r.schroeder

              I am looking at your MCPC2425A (analog input proportional phase angle SCR) datasheet and I don't see a typical or maximum turn-off time.  I have an application that requires that I can get half cycle response.  That is if I cut the 0-5V input to 0 the next half cycle will in fact be off.  I notice in the data sheet for the PMP series such as the PMP2425 which I had also considered the tune off time is listed at "1 cycle" which implies a full 16.7mS for 60 Htz if I read it correctly so it would not meet my needs.

              • 514. Re: Have a question about solid state relays and their applications? Ask me!
                bobleon

                Hello Pete,

                 

                the Question:

                Do any SSR’s come w both a NO and a NC set of contacts?

                 

                I’m looking to replace a mechanical micro switch w a small ( 8mm dia)  proximity switch. My application (triggering two solenoids to (alternately) move an air cylinder back and forth ) requires both a NC and a NO circuit.

                 

                I’ve not found a prox w both a NO and NC circuit ... so instead i’m thinking of triggering a relay w the prox ... and (since this runs millions of cycles) i’m hoping to make the relay solid state.

                 

                so:

                Do any SSR’s come w both a NO and a NC set of contacts? Or is there some other way to do this?

                 

                Bob Leonard

                Detroit

                • 515. Re: Have a question about solid state relays and their applications? Ask me!
                  rsmith22

                  hey pete i am useing finder type 40.61 16a 250v relays with a 90.61 relay block and want to transition over to solid state. can you help with where to start.

                  • 516. Re: Have a question about solid state relays and their applications? Ask me!
                    rsmith22

                    Hello Pete,

                     

                    I would LIke to know where to start with solid state relays. We have been having issues with are relays and relay blocks every few months. So i was doing so looking around and found solid states and wanted to know what solid state to use.

                    WE are current using mechanical relays made by finder. They are: Finder type 40.61 16 amp 250v with a 110 trigger, when relay closes it sends 12.5 amps threw so we are in the 80-85% reange of max useage. also are relay blocks are finder type 90.61.

                    any suggestions help thank you

                    Ryan

                    • 517. Re: Have a question about solid state relays and their applications? Ask me!
                      davids.

                      Hi Pete, my daughter recently purchased a warehouse for her business, right now the lights are on conventional switches.  She wants to convert to Lutron Caseta smart switches to make sure all the lights are off when everyone leaves for the day.  The switches she got are rated for 5 amp and according to Lutron they will handle the full 5 amp rating.

                       

                      The lights in the warehouse are Volt Lighting commercial high bay LED  rated at 250 watts continuos power.  This puts them at 2.0833 amps per light, so right now she can only run 2 lights off a switch.  She has 9 of these lights on 2 circuits.

                       

                      I am looking into running the lights off an SSR with 120vac input, 120vac output.  I would like to know what the input current draw on a 120vac input SSR is.  The reason I am wondering about this is right now one of the circuits is controlling 2 of the lights and when I tested the Caseta smart switch the outside of the metal junction box  got uncomfortably hot, even though the switch was below the rated amps.  I am thinking that if I can get the current draw down through the switch the temp will come down and I will be able to spilt the lights more evenly between the 2 circuits.

                       

                      Can you recommend an SSR for this application also?  Thanks

                      • 518. Re: Have a question about solid state relays and their applications? Ask me!
                        jrslay

                        HI Pete, 

                         

                        If an SSR (crydiom EL series 240 A) with 12 VDC control voltage is driven by 24 VDC instead what are the adverse effects?  I suspect it will shorten the lifespan, but is there a curve or rule of thumb for that kind of condition? 

                        • 519. Re: Have a question about solid state relays and their applications? Ask me!
                          sailorman2

                          I'm new at working with electronics, I want to build a switch  or relay that will come on and off by battery voltage, when battery charger comes on and the voltage increases to 14 +volts dc it will switch on a load of .5 to 1 amp and turn off when battery voltage drops to 13.5 to 13 when charger shuts off, can I use a mosfet n enhance transistor? This will be my first electronic project, thanks Charlie.

                          • 520. Re: Have a question about solid state relays and their applications? Ask me!
                            devesh_rai

                            Hi,

                             

                            I have an application which would involve having data lines connected to a microcontroller which would signal at lvttl (3.3v) levels and also take in 24v for a resistive load (~600mA). I have previously used a mechanical relay for this same application without any major issues. I'm in the process of switching the microcontroller on this to something more modern, more powerful, cost effective and much smaller in size and decided to switch out the mechanical relay with a Solid State Relay. This would provide much higher life for the product, help me with making the part smaller and at the same time make manufacturing easier as the pick and place can mount the SMD SSR not requiring me to hand solder these separately.

                            From the datasheet I'm using connection "C" as that would be more suitable for the load I'm planning.

                             

                            My issue is: The application my board connects to has a common ground. The lvttl lines and the 24v input both share the same ground, how would I handle that if I'm using a G3VM-61E1 or something similar? It seems internally the logic is similar to an N-Channel style mosfet.

                             

                            So how would I handle giving both my digital signals and HV supply a common ground in this case?

                             

                            If this isn't the right place to ask this question, please feel free to point me in the right direction or any resource you think is more appropriate.

                             

                            Thanks,

                            1 31 32 33 34 35 Next