Ye Olde Rocket Forum

Go Back   Ye Olde Rocket Forum > The Doctor is In! > Ask the Doctor
User Name
Auctions Register FAQ Members List Calendar Today's Posts Search Mark Forums Read

Thread Tools Search this Thread Display Modes
Old 09-30-2015, 04:40 PM
UlteriorModem UlteriorModem is offline
Intermediate Rocketeer
Join Date: Sep 2015
Posts: 81

For now yes... please. Poor horsie..

The ply is a good idea.

But I will revive this thread once mine arrives and I do a little peek and poke.

Till then !
Reply With Quote
Old 10-06-2015, 11:15 AM
Woody's Workshop Woody's Workshop is offline
Join Date: Mar 2012
Location: Reed City, Michigan
Posts: 231

So could one modify this unit to be able to use a 12v battery?
Such as a small motorcycle or garden tractor battery?
Reply With Quote
Old 10-06-2015, 05:30 PM
UlteriorModem UlteriorModem is offline
Intermediate Rocketeer
Join Date: Sep 2015
Posts: 81

Yes quite easly Woody. There is the jst connector inside which could be connected to a jumper run out of the case through a hole of some sort. Or put a jack of some sort into the bottom of the battery case cover. Observe polarity of course.

On the one I just received the positive lead for the connector is on the pin closest t to the bottom of the battery tray opposite the lid.

For the record as I understand it the jst connector is rated for 10 amps continuous and is connected with what appears to be 24 gauge wire.

Now for the diagnosis. I got her open with little trouble and found the following:

There is not much in the way of circuitry. A printed circuit board populated as follows. A very large (6A10) diode to protect against reversed polarity to the LED and buzzer. That diode is a brute rated at 6 amps at up to 1,000 volts! Then the led itself and its 1/8 watt dropping resistor. The 'switches' are just leaf spring tabs that are pressed down with the buttons. The key 'switch' is a similar matter with two leaf springs that make continuity when the 'key' metal pin is inserted between them. All wiring inside the unit is 24 gauge. The NEC does not give ampacity for 24 ga wire but I believe in these short lengths it is capable of 10 amps.

I tested the current with a really cheap harbor freight multimeter but measured 40ma with the led on and 60ma with the buzzer activated. No way to measure the peak current but with a 3S 1800ma lipo at a 'storage' charge (3.8V/cell or 11.36v total) it incinerates estes starters and Quest Q2's go off with a resounding snap

That pretty much sums it up except for the JST connector is glue welded into the case. I was hoping to replace it with something a little more robust but when its all said and done it is probably adequate for the average task of low to mid power rockets.

Last edited by UlteriorModem : 10-06-2015 at 07:05 PM.
Reply With Quote
Old 10-06-2015, 09:39 PM
LeeR's Avatar
LeeR LeeR is offline
Retired with Way Too Many Kits
Join Date: Jun 2007
Location: Colorado
Posts: 1,737

Sounds like the controller should serve its intended use very well. Should you really feel the need to replace the JST connector, don't underestimate the capability of Mr. Dremel with his cutting wheels and grinding stones!
Lee Reep
NAR 55948, L2

Projects: Super Sky Hook, Estes Saturn V
In the Paint/Detailing shop: Estes Saturn 1B
Completed!: Der Saturn Max
Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -5. The time now is 01:03 PM.

Powered by: vBulletin Version 3.0.7
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Ye Olde Rocket Shoppe 1998-2018