HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Jun 30, 2008, 07:39 PM
PLD
Magicsmoke maker
PLD's Avatar
Australia, QLD, Charters Towers
Joined Dec 2003
17,398 Posts
Greggold,

The PLD-BAC-001 (or just BAC) is a BEC Alarm Combo unit, basically it provides 5V output and an alarm for low voltage for lipos being used in HLG/DLG situations. Because of the HLG/DLG focus it's not surprising that many others outside of the discipline haven't really heard much of it.

Now, as per your request, I've added a pair of photos showing the prototype 5A ESJ in use with a Ni* pack.

Paul.
PLD is offline Find More Posts by PLD
Reply With Quote
Sign up now
to remove ads between posts
Old Jul 01, 2008, 08:53 AM
PLD
Magicsmoke maker
PLD's Avatar
Australia, QLD, Charters Towers
Joined Dec 2003
17,398 Posts
Update

Circuit boards are now onboard with courier, just a case of them flying their way from there to here now

Paul.
PLD is offline Find More Posts by PLD
Reply With Quote
Old Jul 01, 2008, 12:25 PM
HyperFlight Support
Neil Stainton's Avatar
United Kingdom, England, Stratford-upon-Avon
Joined Feb 2001
3,910 Posts
I've got an idea. Would it be feasible to use a small neodymium magnet and a hall sensor instead of a jumper? Magnet removed = on. Magnet present = off. The benefit is of course that no hole would be required in the fuselage, as the flux would penetrate several mm of glass / carbon / kevlar / balsa, etc.

Neil.
Neil Stainton is offline Find More Posts by Neil Stainton
Reply With Quote
Old Jul 01, 2008, 03:14 PM
Registered User
Erik.R's Avatar
Haute-Savoie, France
Joined Feb 2006
302 Posts
I think I've seen that somewhere before
Erik.R is offline Find More Posts by Erik.R
Reply With Quote
Old Jul 01, 2008, 07:43 PM
PLD
Magicsmoke maker
PLD's Avatar
Australia, QLD, Charters Towers
Joined Dec 2003
17,398 Posts
Yes, you could use a magnet + hall sensor but there's a couple of issues;

1) you'll require a lot more circuitry (hence larger more expensive board)
2) it's potentially more prone to false turn-ons (or offs)
3) how would you hold the magnet in place?

A cheaper and more human-doable option if you want to still go for the whole magnet thing is to install a Normally-open reed switch onto the board where the 2-pin jumper currently rests, then a magnet will simply close the contacts when nearby, just the same effect as the jumper would have when inserting into the socket.

How's that sound?

Paul.
PLD is offline Find More Posts by PLD
Reply With Quote
Old Jul 01, 2008, 09:33 PM
PLD
Magicsmoke maker
PLD's Avatar
Australia, QLD, Charters Towers
Joined Dec 2003
17,398 Posts
Regarding the reed-switch option, I can add it as part of the product line up, though the reed switches cost a bit more than a simple jumper.

I was thinking it might be an idea to put the reed switch on the back of the PCB and adhere it down. I'll do some experiments here to see how it goes. I still personally have some minor reservations about the issue of the 'disarming' magnet slipping off since there's not likely to be enough magnetic pull to hold it on. Also, I'm not sure how well these reed switches cope with permanent fields and I'll have to see if Neo magnets will potentially damage them internals (I've had this happen on some latching reed switches in the past, they were designed for normal low flux ferrite magnets, I used neo magnets on them and promptly destroyed the internals).

Paul.
PLD is offline Find More Posts by PLD
Reply With Quote
Old Jul 02, 2008, 12:25 AM
PLD
Magicsmoke maker
PLD's Avatar
Australia, QLD, Charters Towers
Joined Dec 2003
17,398 Posts
Reed switch update

Just made up a reed switch version and found an interesting property.

If I do use neo magnets I find it generally works best by approaching the reed from one end or the other, not placing the magnet directly over the center of the reed. With the neo magnets I could be within about a 20mm range and it'd turn off. This could be seen as a feature/problem depending. I'd personally see it as a feature in the sense that you aren't required to have your magnet placed 'absolutely perfectly' , so you could in fact rough shod it with a piece of tape or a cable velcro-strap with the magnet glued on.

I'll make up a little video of the unit in operation just now.

Paul.
PLD is offline Find More Posts by PLD
Reply With Quote
Old Jul 02, 2008, 02:30 AM
Registered User
Erik.R's Avatar
Haute-Savoie, France
Joined Feb 2006
302 Posts
Quote:
Originally Posted by Erik.R
I think I've seen that somewhere before
Quote:
Originally Posted by pldaniels
What I'm working on is a magnetic version that uses a NC reed (normally closed in the absence of magnetic force).
http://www.rcgroups.com/forums/showp...postcount=3019

Erik.R is offline Find More Posts by Erik.R
Reply With Quote
Old Jul 02, 2008, 02:59 AM
PLD
Magicsmoke maker
PLD's Avatar
Australia, QLD, Charters Towers
Joined Dec 2003
17,398 Posts
That was a while ago - wasn't until now that I got to flesh it out I think I gave up at the time because I was actually trying to make a latching reed switch, as apposed to a NO/NC type.

BBL.
PLD is offline Find More Posts by PLD
Reply With Quote
Old Jul 02, 2008, 06:07 AM
PLD
Magicsmoke maker
PLD's Avatar
Australia, QLD, Charters Towers
Joined Dec 2003
17,398 Posts
Just cutting out a video for you guys to show off the ESJ's... talk about having to take and retake... and retake again trying desperately to get some coherent speech out of me Lots of "Oh damn!" or "Arugh!" moments in it.... thank God for video editors.
PLD is offline Find More Posts by PLD
Reply With Quote
Old Jul 02, 2008, 08:21 AM
PLD
Magicsmoke maker
PLD's Avatar
Australia, QLD, Charters Towers
Joined Dec 2003
17,398 Posts
Well, this is my first ever "talky" video attempt, so I hope it doesn't come across too badly.

http://www.pldaniels.com/flying/vide...sj-001-360x288
PLD is offline Find More Posts by PLD
Reply With Quote
Old Jul 02, 2008, 09:11 AM
PLD
Magicsmoke maker
PLD's Avatar
Australia, QLD, Charters Towers
Joined Dec 2003
17,398 Posts
PCB udpate

Seems something has gone AWOL in China and the boards are still onboard with FedEx in Wuhan, ie, they haven't moved an inch in the last 24hrs

Paul.
PLD is offline Find More Posts by PLD
Reply With Quote
Old Jul 02, 2008, 04:26 PM
HyperFlight Support
Neil Stainton's Avatar
United Kingdom, England, Stratford-upon-Avon
Joined Feb 2001
3,910 Posts
Hi Paul,

Thanks for running with the magnet idea. I like using a reed switch, because that would mean NO off current. As far as keeping the magnet in place, I was thinking that a small piece of iron (eg bit of a knife blade) could be placed next to the unit, to act as an attractor.

Your video is great, it must take a lot of guts to make one of yourself. BTW you are younger than I expected!

Also well done for keeping posting, even if it looks as though you are talking to yourself. I am sure I would get dispirited by the lack of response, but you sensibly keep at it.

Regards,

Neil.
Neil Stainton is offline Find More Posts by Neil Stainton
Reply With Quote
Old Jul 02, 2008, 04:48 PM
PLD
Magicsmoke maker
PLD's Avatar
Australia, QLD, Charters Towers
Joined Dec 2003
17,398 Posts
Neil,

Quote:
I like using a reed switch, because that would mean NO off current.
Sorry if I misled on this matter - the reed switch version actually consumes the same amount as the jumper version (about 7uA), it's simply that the reed has replaced the jumper.

For others reading this who are a bit unsure, 7uA is 0.007mA. If you have a 180mAh pack that means it would last (180 / 0.007)hrs, or just a bit over 25,000hrs, just a bit shy of 3 years. Most batteries naturally decay at a rate faster than that.

The 7uA discharge current is caused by a 1megaohm resistor that is used as part of the pullup/pulldown circuit on the board to turn the MOSFET gate on and off.

When the circuit is 'off' there is no current flowing through to the other side (eg, the receiver/servos etc), that side is completely switched off.

Quote:
Your video is great, it must take a lot of guts to make one of yourself. BTW you are younger than I expected!
I have to say, it really is a lot harder than I anticipated to do such things. So many things that you realise you do subconsiously, like banging your foot against something or pulling stupid faces, I also loathe the "umms and aaahs". Thanks for the youth compliment, makes me feel better considering I just slipped past my mid 30's the other week (actually, it's all makeup, lighting and a good dose of photoshop 'blur' )

Paul.
PLD is offline Find More Posts by PLD
Reply With Quote
Old Jul 03, 2008, 09:21 AM
PLD
Magicsmoke maker
PLD's Avatar
Australia, QLD, Charters Towers
Joined Dec 2003
17,398 Posts
Status update

PCBs are still held up in China at the airport. Not sure what's going on over there but it's quite unusual for it to have been delayed this long. So much for my grand hopes of it potentially arriving for the weekend.

Paul.
PLD is offline Find More Posts by PLD
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Question Attaching 2.5mm Male Power Jack to PCB ejaf DIY Electronics 11 Feb 26, 2007 08:24 PM
Power jack for your slope plane stegre Slope 9 Jan 03, 2003 03:21 AM
Radio Shack charger/power jack- help Randy G Electric Sailplanes 6 Jan 10, 2002 05:30 PM
Radio Shack charger/power jack- help Randy G Electric Sailplanes 0 Jan 05, 2002 08:11 PM
Radio Shack charger/power jack- help Randy G Electric Sailplanes 0 Jan 05, 2002 08:11 PM