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Author Topic: fitting a failsafe  (Read 2760 times)

hollowhornbear

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fitting a failsafe
« on: April 20, 2011, 02:30:19 pm »

Ok Guys, how do you wire a failsafe into the pump circuit?  i'm using a peristaltic pump and reversing switch unit. pictures/diagrams please.
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Mankster

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Re: fitting a failsafe
« Reply #1 on: April 20, 2011, 02:59:53 pm »

Is it a servo controlled reversing switch or one that plugs straight into the Rx? Either way, you plug the failsafe unit into the RX and the switch (or servo that controls it) into the fail safe.

Patrick Henry

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Re: fitting a failsafe
« Reply #2 on: April 20, 2011, 03:29:09 pm »

Yep, exactly the same principle as you plug in an auto leveller...

Rx to failsafe...failsafe to pump  controller.
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hollowhornbear

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Re: fitting a failsafe
« Reply #3 on: April 20, 2011, 03:57:47 pm »

robbe switch No.8283 and subtech AFS-2
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Subculture

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Re: fitting a failsafe
« Reply #4 on: April 20, 2011, 04:03:06 pm »

Some switchers come with a built in failsafe e.g. Engel, Thunder Tiger and Bruggen relay switchers. Subtech failsafe is a good choice, as it has a nice long delay to prevent minor signal hiccups upsetting your trim.

Also worth looking at something to prevent over pressurisation of the ballast tank/bag. Best IMO is a mechanical relief valve t'd in between the pump and the tank which vents any water outside. I'm not aware of any commercial solution so you will have to construct your own. Or you can use a pressure switch which is fitted in a similar manner but cuts the electrical feed to the pump once a certain pressure is reached. You can obtain them from Norbert Bruggen.

Without that failsafe you could end up in a situation where if the pump stayed on, the pump will first blow you bag, then continue to pump water until it blows your dive module. The chance of this happening is remote, but factor in sods law, and the probability narrows considerably.  :}

Mankster

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Re: fitting a failsafe
« Reply #5 on: April 20, 2011, 05:58:48 pm »

I go for zero delay on the failsafe and a Receiver that filters out glitches. Seem to work well for me, hardly ever have my boat poping to the surface and no worries that the sub has gone off somewhere it shouldn't have before the failsafe acts.

Subculture

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Re: fitting a failsafe
« Reply #6 on: April 20, 2011, 06:01:36 pm »

I like a fast failsafe on all functions (e.g. throttle) except the ballast system. Guess it boils down to personal preference.

hollowhornbear

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Re: fitting a failsafe
« Reply #7 on: April 21, 2011, 09:34:58 am »

my failsafe doesn't have plug a socket to plug the switch unit into. it has 2 screw terminals one goes to postive side of the load (in this case the pump) the other in the negitive of the battery.
tried this and seem to have blown  the switch as it only pumps in one direction, wether the failsafe is connected or not.
 >>:-( >>:-( >>:-(
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Subculture

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Re: fitting a failsafe
« Reply #8 on: April 21, 2011, 09:54:20 am »

I had a look on the Subtech website, but was unable to find the model of failsafe you describe. However when you describe 'screw terminals', that suggests this device is designed to switch power, and you probably have the wrong failsafe for this type of system

Can you have a look and report back on which one of those you have-

http://subtech.co/acatalog/SubTech_-_Products.html

The FS1 is the one suited to your application

I found the Robbe reversing switch, that looks fit for purpose. http://data.robbe-online.net/robbe_pdf_en/8421.pdf

hollowhornbear

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Re: fitting a failsafe
« Reply #9 on: April 21, 2011, 10:28:44 am »

Andy will do this evening, looking on subtech would the SubTech - DFS1 Dual Function Switch w/built-in failsafe, do the same job in one package?
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Subculture

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Re: fitting a failsafe
« Reply #10 on: April 21, 2011, 03:45:56 pm »

No. You need an h-bridge switch for bi-directional control.

If you want an all in one solution look at the engel switch or the controller from Norbert (same thing I think).

http://www.engel-modellbau.eu/catalog/product_info.php?cPath=2_67&products_id=1360

http://modelluboot.de/Elektronik/BTS.html

Sub driver

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Re: fitting a failsafe
« Reply #11 on: April 21, 2011, 04:43:16 pm »

Hollowhornbear.

see below 14.99 from your local model shop for aircraft, the fly boys use them to cut the throttle in case of signal failure so the model does not go out of sight , comes with an adjustment pot for servo throw and plug and socket.

Regards Sub.
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Patrick Henry

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Re: fitting a failsafe
« Reply #12 on: April 21, 2011, 04:48:11 pm »

That would be ideal for the Biber...any maker's name Sub?


Rich
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Sub driver

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Re: fitting a failsafe
« Reply #13 on: April 21, 2011, 04:53:03 pm »

HI .
Yep its GWS as on the item FS1, the dimensions are ......40mm long x 20mm wide x 8 mm deep. :-)

Regards Sub.
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Sub driver

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Re: fitting a failsafe
« Reply #14 on: April 21, 2011, 04:57:11 pm »

Rich,

Just checked out the tinterweb and Sussex Model Center sell them, and I lied........... 13.99 from them  {-) {-)

www.sussex-model-centre.co.uk

then r/c equipment then failsafes.

regards sub.
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Subculture

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Re: fitting a failsafe
« Reply #15 on: April 21, 2011, 05:42:28 pm »

Or half that from here- http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=4283

Personally when you can get an integrated failsafe, switcher with low voltage, over pressure and flood detection for 26 or thereabouts, I know what I'd get, but you pays your money.......

hollowhornbear

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Re: fitting a failsafe
« Reply #16 on: April 21, 2011, 05:55:34 pm »

problem is only running 6V, so engel no good, unfortunately.
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Subculture

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Re: fitting a failsafe
« Reply #17 on: April 21, 2011, 06:16:03 pm »

Ah right. Peristaltics usually run on 12 volts. The controller would switch 6 volts but the low voltage detector would be a problem. i expect it's just potential divider fed into the A-D converter on the microcontroller, and could be modified by changing a couple of resisitors, but I don't expect you want those complications.

Well you have a couple of failsafes to choose from anyway.

Patrick Henry

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Re: fitting a failsafe
« Reply #18 on: April 21, 2011, 06:32:04 pm »

Thanks for that Sub, much appreciated...


Rich
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hollowhornbear

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Re: fitting a failsafe
« Reply #19 on: April 21, 2011, 06:36:57 pm »

that's easy for you toa say Andy, and you may understand it! remember i'm a tin basher.
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Subculture

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Re: fitting a failsafe
« Reply #20 on: April 21, 2011, 06:38:57 pm »

Better than a bishop basher!  %%

hollowhornbear

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Re: fitting a failsafe
« Reply #21 on: April 21, 2011, 06:57:07 pm »

unless it's the baby eating bishop of bath and wells!  %%
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