danny_galaga

Can you disconnect the capacitor? I don't think the capacitor should affect it, but you are thinking it and that would be the easiest way to know for sure. In any case, it would boil down to something going on with the regulator since it normally wouldn't do this.

In all seriousness though, this is a good outcome. I flew out of Heck Field when test flying a demo plane. Cane fields all around. Pretty safe for emergencies, but obviously it's not going to be tidy.

A couple of questions:

Why were emergency crews 'stunned'? Was a lizard person flying it?

Why are casa investigating?

59 minutes ago, BrendAn said:

mine is a microair danny. for some reason i thought it was an mgl. it works fine but it makes the tacho needle go haywire when i transmit. 

I wonder if the tacho wire is running along the aerial coaxial cable or something and it's picking up energy? Seems more like the radio is fine, and the tacho needs investigating 🤔

On 06/06/2025 at 3:36 PM, BrendAn said:

i was looking at whats available after reading this thread.  seeing what people think of mgl i guess i will have to replace that soon. funke have model that fits the same hole .

 

Is yours working alright at the moment though? I was only going to replace mine because I thought it was dying. Even my mechanic was happy about the improvement when I replaced the starter battery. 

52 minutes ago, Blueadventures said:

They can be found in tree bark, at night use a UV torch as they light up a bit.

No thanks 😄

5 hours ago, facthunter said:

More likely to get in your boots IF you leave them outside the tent. It's a Territory thing. Nev

Well, central anyway. I grew up in Darwin and I don't think I ever saw a scorpion. A BILLION cockroaches though. I don't miss those 😄

Well, my MGL seems to have come good! The only thing that has changed is that the starter battery was going downhill fast, so after the last flight (where it only just started, even after charging it for 30 minutes) I put a new one in. Could it be my radio is a bit sensitive to the extra, and constant current draw of my dicky battery? Thoughts Kyle? 

In any case, should I ever have to replace the radio, Trig is getting such a good rap I would be silly not to go in that direction. I'm thinking if I mount it under the seat, I could make the aerial coaxial cable about 1.5 metres shorter, which can't hurt 🙂 

8 hours ago, BurnieM said:

Can we start off with price ?

What is the price of a new MGL, new Trig and for comparison, new Icom and new Garmin.

 

Trig TY91 is about $2800 in Australia. From memory, my MGL was about $1200 USD 

If you are using a currently available model of radio, what is it, and are you happy with it?

I have an MGL. It seems to have gone downhill fast. I have time off next two weeks so I can have a really good at the wiring, aerial etc. but the radio started off well, and the plane only has about 6 hours total flight time, so I feel it probably is the radio. When I told an avionics guy what brand, he asked how much I paid. When I told him it was free, he said that's about the right price 😄. My guy helping with the test flying and another guy at the hangar didn't think much of MGL either. The other guy actually threw his away 😲 They are very happy with Trig TY91, so that's on my radar. My only concern there is it's one of those 'head unit and base unit ' jobbies, which will make installation in my case a bit of a bother, depending on whether I can just join them.into one unit or not...

3 hours ago, BrendAn said:

Why don't you pay a few dollars a year . It supports the running of this site and you will get your 30 minutes.

A full 30 minutes 😲

Here's a post of mine on a different forum. 2004. Notice the link in the first post?

https://forum.arcadecontrols.com/index.php/topic,20073.0.html#msg161529

51 minutes ago, Red said:

Note to admin, can we have a longer time to edit posts, I know it's to preserve context in replies but its ridiculously  short.

Admittedly its a fault of mine that I often don't explain things properly in my posts and need to edit.

Many of us have asked this. Not going to happen. You've got 15 minutes and then all your mistakes are locked in forever 😄

1 hour ago, Underwood said:

My Carmo install goes through master switch and fuse to battery.
I didnt pay attention to grounding the case as I assumed it was not actually electrically connected to any internal components but was merely a heatsink.
Maybe I should go back on that?
I suppose checking for continuity between the negative wire from the regu and the case would confirm whether or not grounding the case provides any purpose electrically for the carmo?

Well I haven't added an earth to mine. I guess it could be earthing through that foil covered fibreglass heat shield I guess 😊

20 hours ago, Red said:

Whilst it's common for VRs to require the case to be grounded the Carmo makes no mention of doing this.

Also did you connect it direct to the battery with no fuse as the Carmo instructions indicate?

Yeah, I figure since the Carmo is made for aircraft it's fully above ground electrically. The Ducati one obviously is for motorbikes which use the frame for negative ground.

My installation benefitted from being a clean install. Plenty of air movement around the device, but the air that's there isn't going to be very cool. That's the kit position and I didn't want to waste time doing something different. Anyway, my hope was that even it's a bit warm there, it's supposed to run cooler than the original anyway. So far the longest flight has been roughly 80 minutes 

2 hours ago, BurnieM said:

How much is a new rec/reg ?

 

Buying a new one and trying it would save a lot of time and 'pointsforpilots.blogspot' recommends Rotax owners carry a spare regardless.

 

 

You do have to be wary. Plugging in a new one into something that caused the old one to fail is an expensive diagnosis 😄

3 hours ago, skippydiesel said:

 "Specs in Rotax manuals"

 

Fair enough BUT which one of the four manuals?😈

 

You only need a ball park figure to get an idea if it's working or not. Battery at rest voltage is about 12.4V. If you see more than that when the engine is running, it's charging. It should if course be significantly more. We used to see so much variation when I was an auto electrician we drew a line at about 13.2v . Between that and about 14.4v is fine. I don't know that you'll easily test it off the plane. A dedicated workshop might have a suitable AC output to hook it up to. For you, your best source is the running engine 🙂

If you do underwoods test, you'll know your charging system is working. If it's working, that is how you test your regulator 🙂

Just for sh*ts and giggles, I'm going to temporarily install the capacitor on my set up. I have an MGL radio, which is not highly regarded around the hangar, and since it seems to be getting worse without anything else seemingly changing, I suspect it's a bit dodgy. But it can't hurt to put that capacitor in the circuit and see if the radio improves. Ill report back on the results. Could be a week or two.

16 hours ago, Geoff_H said:

I expect that the Capacitor is to give the MOSFET a voltage level at which to switch off. When the Capacitor discharges into the aircraft electrical system iits voltage will start to drop, the control circuit will see this and turn the MOSFET on.  When the Capacitor reaches the voltage of the set voltage for aircraft operation the control system will turn the MOSFET off.  This cycle continues as required.

The battery is already doing that. If not, the capacitor would be internal otherwise your whole system is relying on the installer dong that correctly- for instance if people are leaving them off because the Carmo doesn't need it, then B & C would be getting a bad rap. I feel either they are playing it safe by recommending you use one (if it's not needed it won't make any difference) or else maybe their design makes the same amount of noise as the Ducati 🤷‍♂️

29 minutes ago, facthunter said:

They don't use just a simple relay. It includes windings reacting to the voltage as well as Current flow, all spring tension adjusted, and it  modulates  by opening and closing the Points . Some times a  resistor is also across the Point  to minimize the current change. A cut out was used as well to prevent reverse current on shut down. Later Diodes do the same thing. They need cooling.  Nev

I used to be an auto electrician 😉

1 hour ago, Geoff_H said:

Not exactly the same.  The non permanent magnet alternator/generators alternator the magnetic current of the rotating field.  The stator voltage is then a function of rotating flux density and velocity.  The relay was altering the field current.   With a permanent magnet rotor the field flux is fixed, the velocity varies so the output voltage varies with rpm, so you have to  convert the output  voltage to 14volts (or 28volts depending on system).  It is just the same as a phone charger that converts 110 or 240volts to 5/12volts automatically. 

Right you are. I think we talked about this before. My point is I don't think there is a need for a switch mode system, particularly since we've had this type of 'alternator' from before there was such a thing. With these low current alternators, the output amperage isn't that great. 22 amps total output for instance compared to about 5 to 10 amps for a rotor field. Totally doable with the same hardware, whether that was relays or now with transistors

9 minutes ago, skippydiesel said:

FYI - Silent Hektik do not sell outside the EU. 

 

However some determined  RV 12/USA pilots have found ways around this; https://vansairforce.net/threads/silent-hektik-voltage-regulator-install.130921/

 

I can't remember if I bought my Carmo from the Aussie distributor or not. I guess I did. Maybe different manager now? I didn't have any dramas, but that was several years ago 

Incidentally, my Carmo runs at a solid 14.3V

2 hours ago, Geoff_H said:

Doesn't it depend upon whether the output from the alternator is below or above 14V?.  I think that you are right but if you use straight resistance you may have a heat dissipation problem.  Yes I agree that the oscillation frequency is high, that way only a small transformer is needed.  In the 1970's I had a job that needed 5volts from a 24Volt supply.  Two racks of many 2n3055's tied together, then switch mode became available,  one small package 1/10 the panel space and no heat issues.

Except maybe at the very lowest rpm, the alternator will be putting out more than 14V. Not sure of exact figures but I would guess easily over 20V if no load. I think on a 3 phase car alternator it's over 50V. In the olden days (say 40 or so years ago) the regulator consisted of a relay. Below a certain voltage it was closed and above a certain voltage it would open. In this way it would vary it's rate of vibration, depending on the load, which had the effect of varying the voltage. Of course now it's done with a transistor. Same principle though. 

46 minutes ago, Geoff_H said:

If I understand it correctly the way a permanent magnet generator works is the same as a switch mode power supply.  The AC voltage from the generator that will be speed dependent.  This voltage is rectified and a large capacitor charged.  A control circuit will turn a power transistor on and off through a transformer at a rate that will give an output at the aircraft system charging voltage the rectify this ac voltage and connect the rectified output to the system.  Well in a similar way to this.

Sorta. A switch mode power supply ramps up the frequency several thousand hertz before then converting that to the required voltage. There isn't a need here. You aren't converting a voltage, just regulating it.