mccr3328
Well-Known Member
- Joined
- Jan 17, 2009
- Messages
- 286
- Reaction score
- 1
It varies significantly, but most automotive-oriented glow plugs draw 5-10 Amps for some seconds. I don't know if you're latch kit could do that, but the you would definitely need a certain battery to do it, probably nicad. I believe plugs meant for hobbyists have lower requirements. I have no idea what this one uses.Originally posted by m85476585
It looks like a nice product, except for the price. (BTW, this isn't the first use of glowplugs. AT's EFC timer also uses them).
If Perfectflite thinks my MAWD latch time kit is OK, I'm sure it could fire glowplugs.
What are the current and voltage requirements for glowplugs?
The No-Match device uses a standard RC airplane glow plug rated to draw ~3 amps at ~2 volts. It uses a cheap throwaway 3 volt lithium CR123 battery available at any drug store. (They don't generate any significant magnet fields.) It will run all season on a battery. On his current and earlier website, he has shown that the unit will fire more than 500 times on one battery.Originally posted by mtwieg
It varies significantly, but most automotive-oriented glow plugs draw 5-10 Amps for some seconds. I don't know if you're latch kit could do that, but the you would definitely need a certain battery to do it, probably nicad. I believe plugs meant for hobbyists have lower requirements. I have no idea what this one uses.
EDIT: also, the voltage across the plug has to be around 1.5-2 volts.
Originally posted by bobkrech
if you use this unit more than 80 times it is cheaper, and you don't the an explosives permit to buy the e-match.
Bob
Originally posted by bobkrech
The No-Match unit has been under development for several years. I'm guessing Gary was at Balls 2005 and saw the unit in operation and decided to make a similar one for his reloadables. The AT electronic forward closure is built on the same concept and uses the same type glow plug and the same battery but it has a timer board and g-switch made by Perfectflite built-in, but @ $179 is $100 more expensive than this unit which can be used with any altimeter.
MatthewOriginally posted by matthew
I have to say, I've been wondering where this fits in with the AT EFC-1. Apparently the EFC-1 is patent pending. What actually is being patented? Does the NoMatch system potentially infringe if it's used with a timer?
https://rocketryforum.com/showthread.php?s=&threadid=27971&perpage=20&pagenumber=2/
PC boards conduct heat fairly well, and the electronics are quite close to the glow plug. I imagine if you left it on for long enough, the solder would melt and you might lose some parts. It's also possible that the pcb itself could be damaged.Originally posted by RickVB
Burn through? Burn through what? Can't be the glow plug; I put an igniter on glow plugs for minutes while trying to start a cranky engine with no harm done. The tube? Find that hard to believe; there are plenty of aluminum R/C engine heads that clearly don't burn through from the glow plug. The mount to the board? Possibly, but I doubt that much heat could be transferred through the tube in two seconds.
I gotta agree that mounting the tube on the board seems like a bad idea. Don't understand why it's not separate...
Originally posted by mtwieg
Mounting the glow plug is a problem no matter how I think about it. They're designed for use in applications that tolerate very high temperatures, and they're usually mounted on solid metal. I imagine if you tried to mount one directly to a plastic or wood bulkhead, it would not work.
Originally posted by RickVB
Glow plugs provide their ground connection through their body (i.e., the threads). The glow plug is threaded into the tube (aluminum), which provides the ground here. This is clear because the test procedure has you check resistance between a board terminal and the tube. If you were to mount it in a non-conductive tube or bulkhead, you'd have to provide a grounded conductor in contact with the plug body.
Originally posted by brianc
Just saw that over on Rocketry Planet...
Looks pretty interesting until you get to the $79 (intro) price. Multiply that by two for main & drogue; or by four if you want redundancy and costs add up quick.
The glow plug draws 4.5-9 Amps from the built-in battery, but it only takes 6mA (0.006A) to trigger the firing.Originally posted by mtwieg
How much current draw does the glow plug use?
Yes, the charge container is mounted on the circuit board. One way you could protect the board from the ejection charge gases is by putting it into its own sealed enclosure with only the ejection charge holder sticking out. This way you wouldn't need any holes in the bulkhead either.Originally posted by Manwithbeers
Okay, good looking system.
The charge container is mounted to the board right? The board is much harder to protect from ejection charge gasses unless it is mounted as suggested. ... I really don't like the extra holes in my bulkhead either.
That is a good observation and I already thought of that. All units that I am shipping out will actually have a rim on the ejection charge holder, so that it will take the force from the charge going off rather than the circuit board. This will also help to seal the ejection charge chamber.
The placement on the board looks like it is taking a lot of force from the charge going off in the opposite direction.
I am already looking into developing another version with a remote glow plug setup.
A wire from the board to the charge can and coil assembly would make mounting so much easier and it would probably be a little more rugged with the ability to mount the charge remotely.
The battery holder itself is riveted to the board. The battery clip itself is definitely not enough to hold the battery in place (especially if it points towards the back of the rocket) and needs to be secured to the board with additional means. Tie wraps or even several wraps of tape would be my suggestion.
The battery holder doesn't seem to be very rugged. As suggested the battery and electronics could be mounted more securely but not easily in the current configuration. But then I'm not holding one yet.
I offer custom ejection charge holders. Just specify what I.D. (minimum 1/4") and length you need and I'll send you the price.
A 2g charge is respectable for most rockets up to 3 even some 4 inch diameter tubes but I really need more space than the charge can allows for.
See my previous post.
The intro price is pretty steep.
Look at the battery test video on my website. This was the actual last few seconds of that test. Although this test did not fire an actual charge 500 times and "only" light up the glow plug, I see no reason why the glow plug should fail before then. After all glow plugs are inside a very hot combustion chamber for a very long time during their regular use in model engines. Even if the glow plug does fail, they cost $4 to be replaced.
I really do like the reusable quality but really 500 uses?
You only need 4.5-9V and 3-6mA (0.003-0.006A) to fire the glow plug. The reason for this is because the current from the altimeter is only used to trigger the firing of the glow plug. The glow plug itself is powered by the internal battery. As long as the altimeter turns its outputs on for at least 1/4 second you should be fine. Altimeters should not turn on their outputs for more than 2 seconds, otherwise you risk burning through the glow plug (after it ignites the ejection charge) and damaging the electronics.Originally posted by m85476585
If Perfectflite thinks my MAWD latch time kit is OK, I'm sure it could fire glowplugs.
What are the current and voltage requirements for glowplugs?
Originally posted by Last Frontier
The website is professional. The product is original. The price is pretty steep. Should you suffer a serious failure you just more or less tripled your electronics loss for a duel deployment setup. If a LEUP is still required for the black powder what good does it do to avoid the ematch LEUP requirement?
Originally posted by bobkrech
The No-Match device uses a standard RC airplane glow plug rated to draw ~3 amps at ~2 volts. It uses a cheap throwaway 3 volt lithium CR123 battery available at any drug store. (They don't generate any significant magnet fields.) It will run all season on a battery. On his current and earlier website, he has shown that the unit will fire more than 500 times on one battery.
Quite frankly, I don't believe $79 is a lot money for the unit. In small quantities, he's probably paying at least $30 for the parts, he's doing the assembly, he's supplying the battery and he's paying for the shipping. If he's lucky he might be making $20 per unit. Considering that the cost of a commercial e-match is ~$1, if you use this unit more than 80 times it is cheaper, and you don't the an explosives permit to buy the e-match.
The No-Match unit has been under development for several years. I'm guessing Gary was at Balls 2005 and saw the unit in operation and decided to make a similar one for his reloadables. The AT electronic forward closure is built on the same concept and uses the same type glow plug and the same battery but it has a timer board and g-switch made by Perfectflite built-in, but @ $179 is $100 more expensive than this unit which can be used with any altimeter.
Bob
Originally posted by WillCarney
It does look good but does have draw backs. My L3 rocket for
instance used 4 grams of BP in the top section. This unit would
have to be modified to take more than 2 grams. It is an additional
expense which would over time be made up with the cost of the
e-matches and in the long run save money.
The basic point missed by most is that according to the BATFE
you still need to have a LEUP to buy and use BP for ejection
charges if it does not come with a motor. You get by the e-match
problem but you still have the BP issue in regards to a LEUP.
William
Originally posted by oliver1111
As far as I understand, if you use Pyrodex instead of black powder you won't need a LEUP.
Enter your email address to join: