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Kyle Communications

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About Kyle Communications

  • Birthday 23/05/1959

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  • Aircraft
    ICP Savannah VG XL/ S and Rans S21 Outbound
  • Location
    Burpengary East
  • Country
    Australia

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  1. No they are typically FETS..they are a voltage device rather than a current based device. Essentially they work like a switch when you place a voltage onto the gate and the drain and source then conduct. They are still semiconductors but they dont have any gain like a transistor does. I am trying to keep this as simple as I can because this subject is huge now. FETS are almost taking over the world 🙂 They are silicon switch for a better word. FETS are really common now and most of all your solar inverters and your power inverters etc..anything that switches on and off ans fast they are generally FETS now. They can take a crap load of current through them because their "on resistance" is very small. A lot of FETS have resistance across the junction like 0.28 of an ohm when turned on and even less. There is a mininum voltage that they turn on with but there is still a current limit as the junction resistance is not the lowest until the voltage gets to a higher level. There are so many types of FETS now its crazy...infact RF Output devices are commonly FETS now and are used regularly ...and I am talking lots of power. LDMOS type ones are regularly 1.5kw RF out Infact the main RF output device in a Xcom airband radio is a FET
  2. The wattage loss is very low even at 10 amps (6 watts max) which would be the most current drawn from a dual efis system and ancillaries. That is only while it is turned on. With semiconductors the limiting factor is the device's junction temperature. The reason I dont like relays is it is drawing all your avionics load current through a spade terminal. I much prefer the screw/boltability of the SSR to take all the load. As a case in point just look how many Rotax regulators end up with burnt out spade terminals on the regulators...I would know of 20 or 30 at least...I dont like them odds...its just not a good thing..Thats why AC43 pretty much specifies ring terminal connections when possible
  3. no he had a carb engine spring fail and the engine was running very rough so he put down on the island...emerg services came but they got it sorted and continued onto tasmania
  4. Where is Hogan Island?..There was a incident I know of in Bass Strait. but it wasnt a savannah
  5. Pictures and sizes of the SSR. also the heatsink on the back. I like too that you replace the screws with small bolts and all connections are on lugs not those stupid spade connectors
  6. I did mine a few weeks ago now...did the online stuff and filled out the stuff flashed my CC and literally 45 sec later my medical class 5 appeared in my email. Mark
  7. Nev I know the differences of each to me its the same result. Just different purposes. After 43 years as a electrical fitter mechanic special class ( industrial electronics) and also a radio tech....I think I know what versions are used for what tasks. Working on 11kv and 33kv and 110kv circuit breakers...using solenoid style actuation and distribution authority electrical substation protection and control systems using hundreds of relays also fault finding and contruction of those substation controls..The last 10 years also doing design and development of mains connected power electronics for mass production sets of products to me they are essentially the same just a different scale and type for the purpose. As I said its semantics to me. You just use the APPROPRIATE DEVICE for the job. As I stated I much prefer to use a manual isolation switch within my reach in the cabin rather than a solenoid to isolate a battery that I have my arse sitting in.
  8. WEEEEELL it is semantics really. A relay is still a electromagnet coil and so is a solenoid. The solenoid is a much larger device designed to switch a much larger load and it does have a core that moves internally. The relay is pretty much exactly the same but in a smaller footprint and designed to handle a lot less current but it does the same thing. The relay though does tend to have a "switch" as contacts being NO and NC but there are exceptions where there is only one set of contacts which are NO similar to a solenoid. so it could be semantics or it could be definition..either way they both do the same thing. Yes you could have a solenoid working off a master switch in the aircraft that does isolate the battery. I have seen plenty of "solenoids" fail in my work life and to be honest I dont think I have ever seen a properly rated isolation switch fail. It is a peronal choice I suppose which way you want to go. To me I like the big manual switch right where it can be accessed from the pilot position.
  9. When referring to a Master in a aircraft it usually means the main electric buss for the internal DC for the aircraft. Not the whole system for the aircraft including battery. I believe what you wanted was a isolation switch. I will always have a isolation switch for the very reasons you give above, That really is a given. The master is not that. It is just wordings I suppose and it all just means take accepted practices for making safe the whole electrical system in the aircraft. How far you want to go with that is up to the builder...and the rules of course. There is no requirement for a isolation switch in any aircraft...but it just makes good sense because if a fault like that occurrs you cant just get out of the vehicle at 7000 ft...unless you got a parachute on 🙂
  10. The SSR I posted is NOT for the starter motor to use it is only for the MASTER..which is for the internal DC for aircraft. The starter has a usual generic solenoid/relay to take the many hundreds of amps at start. I would never use it to switch starter motor current. Semantics of wether it is a solenoid or a relay is nit picking words...we all know what it is and what it does
  11. I always use continuous rated switches....none of this 20 sec stuff as they never cut the mustard. 100 to 200 amps continuous..same as this solid state relay its apparently 100 amps continuous Max Surge 260 amps for a short time..heaps of overkill for a master but solid state DC switches are a bit hard to get This mob below also sell Tefzel wire...it all mainly supplied for race cars on this site. But its local here in brisbane 12-24V 100A Solid State Relay WWW.NRTAUTOMOTIVE.COM.AU Solid state relays (SSR) have no moving parts, eliminating failures normally associated with conventional mechanical switching relays. Rated up to 100A, this SSR provides faster switching time, improved...
  12. I have been reading through this thread and to be honest there are a lot of misconceptions here. RFGuy is correct on everything. Always have a isolator switch direct from the battery terminal somewhere as first port of call for isolation. Put that in the negative lead to isolate the return path from anywhere on the frame of the aircraft. This switch needs to be able to pass the 100 to 200 amps that the starter motor requires.... A regulator is a regulator but yes there are older style linear regs and later switching regs but all really need a large capacitor to ensure the electrical buss has filtered flat DC to all the electronics or electrical equipment that requires DC. The capacitor is just a big filter thats all. Diodes are usually 600V PIV in most regulators so highly unlikely of any breakdown if the alternator goes open. Most regulators and especially the genuine Rotax one usually fail internally by heated spade terminals or pcb failures due to being under designed to take the amount of current through those terminals for a long time. This higher current causes heat because ALL connections have some resistance which will create heat and over time this resistance gets higher and then the heat becomes more and so on until there is a failure. Its a good idea to have a master relay..this is usually a solenoid style but those contacts can still weld together..there are some new solid state DC relay ones good for 100 amps that look really good and I am actually going to use these in my next 2 aircraft instead of the older solenoid style type. DC buss needs to be clean..the only way to clean the lumps off the "rectified AC" this stops the noise and buzzing etc in your radio and also much better for any EFIS style equipment
  13. Just beg borrow or steal flatbed trailer. Its easy enough. I bought Mabel from western mid NSW and bought her all the way to north of Brisbane on a trailer. Wasnt a drama at all. Just took her this week down to the hangar for final assembly when I can get a chance to work on her.She has been a long project to totally rebuild from scratch IMG_3311.mov
  14. Well I jumped through the hoops and have now got the class. 5 medical....was all pretty easy with the online course and quizz and it literally came in 30 sec after paying. I had to email my medical certificate to Avmed so will see what comes of that. Mark
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