HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Nov 13, 2011, 08:00 PM
KK4NZS
Nelapaty's Avatar
Virginia
Joined Sep 2006
1,456 Posts
Use it as a master switch or use it for turning one of the chargers off? any suggestions? unless this switch is only used on rc aircraft/helis/cars
Nelapaty is offline Find More Posts by Nelapaty
Reply With Quote
Sign up now
to remove ads between posts
Old Nov 13, 2011, 08:04 PM
PLD
Magicsmoke maker
PLD's Avatar
Australia, QLD, Charters Towers
Joined Dec 2003
17,398 Posts
Should work very nicely as a master-switch. Will save you gradually pit-arcing away a large mechanical switch. You won't notice any significant voltage or power loss over the ESJ100 either, due to the very low MOSFET resistances. Overall makes it safer too for you, though it will feel strange turning on/off so much power with a little toggle switch
PLD is offline Find More Posts by PLD
Reply With Quote
Old Nov 13, 2011, 08:08 PM
KK4NZS
Nelapaty's Avatar
Virginia
Joined Sep 2006
1,456 Posts
Hahaha yes would be very nice probably confuse many people just keep on smiling
Nelapaty is offline Find More Posts by Nelapaty
Reply With Quote
Old Nov 13, 2011, 09:20 PM
PLD
Magicsmoke maker
PLD's Avatar
Australia, QLD, Charters Towers
Joined Dec 2003
17,398 Posts
Just received notice that both the ESJ100A and -HV boards have been shipped; will arrive in ~2wks I hope.
PLD is offline Find More Posts by PLD
Reply With Quote
Old Nov 14, 2011, 08:02 AM
Chillaxin dude!
BulletMaster's Avatar
Newcastle, NSW, Australia
Joined Apr 2003
4,799 Posts
What sort of price level are these going to be at Paul? I have a few aircraft that would benefit from these with magnetic turn-on/off ability. A 12S 50cc sized model, a 9S pylon model (no external plug for streamlining).. plus they might be useful in some of my marine applications.
BulletMaster is online now Find More Posts by BulletMaster
Reply With Quote
Old Nov 14, 2011, 08:19 AM
PLD
Magicsmoke maker
PLD's Avatar
Australia, QLD, Charters Towers
Joined Dec 2003
17,398 Posts
Bulletmaster,

If you go with the magnet-to-turn-off simple option, that's entirely doable with something like a normal glass reed you get from DSE or Jaycar - but if you want something a little more sophisticated and perhaps more reliable, I might look at making a daughter-board to do the on/off switching by 'toggling' the power state. The reason why the toggling option is better is because you can make it require a 1~2 second application state before it toggles, rather than having any random vibration accidently trigger the switch (reed switches are good up to a fairlevel of G-shock but there might be enough in flight with your planes to momentarily disable the system).

Paul.
PLD is offline Find More Posts by PLD
Reply With Quote
Old Nov 14, 2011, 08:21 AM
PLD
Magicsmoke maker
PLD's Avatar
Australia, QLD, Charters Towers
Joined Dec 2003
17,398 Posts
Not sure yet on the pricing, it'll be below $100 but probably above $50... depends on how quick they are to assemble and what sort of bulk pricing I can get on the PCBs and parts. I'll know for sure when the boards get here and I start working with them, who knows, they might come out cheaper!
PLD is offline Find More Posts by PLD
Reply With Quote
Old Nov 14, 2011, 08:34 AM
Chillaxin dude!
BulletMaster's Avatar
Newcastle, NSW, Australia
Joined Apr 2003
4,799 Posts
k... I'll keep an eye out for the finished product Paul..
BulletMaster is online now Find More Posts by BulletMaster
Reply With Quote
Old Nov 14, 2011, 08:52 AM
PLD
Magicsmoke maker
PLD's Avatar
Australia, QLD, Charters Towers
Joined Dec 2003
17,398 Posts
No problem BM, I'll announce it here. The 12S edition could be a rather interesting thing, because the voltage rating on the MOSFETs I'm planning are 60V, so that'll be the upper limit (I like to leave a bit of headroom. What sort of amps are you pulling?
PLD is offline Find More Posts by PLD
Reply With Quote
Old Nov 14, 2011, 09:28 AM
Chillaxin dude!
BulletMaster's Avatar
Newcastle, NSW, Australia
Joined Apr 2003
4,799 Posts
up to 120A... but mostly around 70-90A
BulletMaster is online now Find More Posts by BulletMaster
Reply With Quote
Old Nov 14, 2011, 09:42 AM
PLD
Magicsmoke maker
PLD's Avatar
Australia, QLD, Charters Towers
Joined Dec 2003
17,398 Posts
The 100A "limit" I have set for these boards is based around a conservative estimate; if you put 120A through the 100HV board it'll put out 7.2W of heat, or about 2.4W per MOSFET, that's quite doable, given that the MOSFETs are rated at 40'C/W, so 2.4W = 96'C above ambient and they're rated to 175'C. The PCB will drop that 40'C/W down to about 30'C/W and the power lead itself will draw away heat as well. Of course, I'd not recommend running at 120A constantly and for optimal power it would be prudent to put a small heatsink on the MOSFETs to get them down to 25'C/W overall ( even just a blank of 1mm thick aluminium bonded to them with thermal-glue would do wonders ).

Paul.
PLD is offline Find More Posts by PLD
Reply With Quote
Old Nov 15, 2011, 02:45 PM
KJ4WFG
modbuilder's Avatar
United States, SC, York
Joined Dec 2007
563 Posts
Hi Paul -- Naive question from a non-EE here -- if you power your Rx from one of your other devices like an external BEC or power board or batt, is there any chance you could switch this thing electronically from a spare channel on the Tx ?

R
modbuilder is offline Find More Posts by modbuilder
Reply With Quote
Old Nov 15, 2011, 06:31 PM
PLD
Magicsmoke maker
PLD's Avatar
Australia, QLD, Charters Towers
Joined Dec 2003
17,398 Posts
Modbuilder,

You wouldn't be able to do it directly, but with a suitably designed RX controlled switch you most certainly could, all you need to be able to do is short out the two pins on the ESJ to make it shut down.

Paul.
PLD is offline Find More Posts by PLD
Reply With Quote
Old Nov 24, 2011, 07:47 PM
PLD
Magicsmoke maker
PLD's Avatar
Australia, QLD, Charters Towers
Joined Dec 2003
17,398 Posts
Both boards arrived today. It's interesting to note that the HV version is more than twice the board area compared to the < 30V version.

The standard version I might downgrade to ~60A purely because of the solder contact size on the PCB for the wires, I don't want things too squeezed so it'll be limited to about 6~8AWG wire that I can see for now. The HV board will take big wire, I think it could even handle 0AWG without a problem... but it does bring up a new problem... my soldering iron just will NOT cope with anything bigger than about 5mm diameter. Blow torch time
PLD is offline Find More Posts by PLD
Reply With Quote
Old Nov 29, 2011, 02:36 AM
PLD
Magicsmoke maker
PLD's Avatar
Australia, QLD, Charters Towers
Joined Dec 2003
17,398 Posts
Picture of the 100A unit built (this is not the HV unit).

The wires on this unit are there for testing, as they're not big enough for truly handling 50~100A.
PLD is offline Find More Posts by PLD
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion on/off switch Linkman81 Electric Plane Talk 7 Oct 08, 2011 05:12 PM
New Product PLD-ESJ8A: On/Off/Charge combo switchjack for RX packs or power PLD Batteries and Chargers 1 Jun 30, 2011 12:51 AM
New Product PLD-ESJ8A: On/Off/Charge combo switchjack for small powered planes PLD Power Systems 0 Jun 29, 2011 09:13 PM
New Product Power on/off/charge switch. Simple, Fail-safe. PLD Parkflyers 40 Jun 13, 2009 02:11 PM
New Product PLDaniels Electronic power/switch jack: PLD-ESJ-1A and -5A PLD Hand Launch 80 Nov 09, 2008 10:48 PM