question about wiring a switch

martini · 04 January 2011, 13:34

Short paragraph taken from the installation manual for the Garmin 600ais (transponder):

Wiring the AIS600 to a physical switch to enter Silent Mode (optional)

When in silent mode, you will only recieve ais signals; your position will not be transmitted.
Use the bare wires from the included SRM cable to install a silent mode switch. Connect the yellow wire from the SRM cable to one terminal of a single-pole, single-throw switch (not included) and connect the green wire from the SRM cable to the other terminal. After the switch is installed, when you close the switch, the AIS600 enters silent mode.

I want to install this switch on the panel with the rest of my switches on the switch panel. All my switches are the Carling toggle kind, each with an led wired in series to provide on/off indication.
I don't know for sure but I'm guessing these "SRM cable" wires aren't a straightforward 12v +/- which would allow me to put an led in series as above, most likely they are some sort of low voltage signal.

So would a single throw/double pole switch be my answer? Wire the SRM cable through one pole and the led through the other?
I've just been looking at my usual switch supplier, they don't list a DP/ST in straightforward on/off configuration but do for every other type. Not sure if they make them or not for some reason?

Thank you!

Jizm · 04 January 2011, 13:53

Quote:

Originally Posted by martini

So would a single throw/double pole switch be my answer? Wire the SRM cable through one pole and the led through the other?
I've just been looking at my usual switch supplier, they don't list a DP/ST in straightforward on/off configuration but do for every other type. Not sure if they make them or not for some reason?

Thank you!

Yes that configuration should work and I'm surprised they don't list a DP/ST, have you checked the manufacturer's website, may be a typo or the supplier simply forgot to list it??

martini · 04 January 2011, 15:21

Quote:

Originally Posted by Jizm

Yes that configuration should work and I'm surprised they don't list a DP/ST, have you checked the manufacturer's website, may be a typo or the supplier simply forgot to list it??

Thanks for that, I went on the Carling site and once I figured out which of the huge number of switch series's were my type (G-series), I found they are available. Got a couple on the way from Maplins now

Erin · 04 January 2011, 15:39

You should have waited before ordering from Maplin with their hefty carriage charge. I'm sure I've got some spare from my set-up.

martini · 04 January 2011, 16:18

Quote:

Originally Posted by Erin

You should have waited before ordering from Maplin with their hefty carriage charge. I'm sure I've got some spare from my set-up.

Never mind! I bought spares and a few 3.5mm plugs and sockets as well, postage £2.49

jyasaki · 04 January 2011, 16:22

Quote:

Originally Posted by martini

I want to install this switch on the panel with the rest of my switches on the switch panel. All my switches are the Carling toggle kind, each with an led wired in series to provide on/off indication.
I don't know for sure but I'm guessing these "SRM cable" wires aren't a straightforward 12v +/- which would allow me to put an led in series as above, most likely they are some sort of low voltage signal.

The LED function should be a separate circuit from the signal being switched (i.e. the switch body actually contains 2 switches: one for the signal, and one to control the LED.)

If you can get the existing switch to function as a SPST (or on/off, if you prefer) with the desired orientation, it should work fine.

jky

PeterM · 04 January 2011, 16:30

I love the ability to go into 'stealth' mode........

Now why would you want to ???

martini · 04 January 2011, 16:35

Quote:

Originally Posted by jyasaki

The LED function should be a separate circuit from the signal being switched (i.e. the switch body actually contains 2 switches: one for the signal, and one to control the LED.)

If you can get the existing switch to function as a SPST (or on/off, if you prefer) with the desired orientation, it should work fine.

jky

Thanks jky, I figured it would be a bad idea to try involving led's and 12v supplies etc on the same circuit, I just needed to confirm my interpretation of how double pole switches work. I've since found a little diagram that explains the different types so I'm all good

Erin · 04 January 2011, 17:08

Quote:

Originally Posted by martini

postage £2.49

That's not bad. A little while ago it was a flat rate of £7 regardless of order size to the CI's. They've obviously bucked their ideas up a little. Unless you are using a 12v LED, don't forget you'll need a resistor in series to step it down to the usual 2.1v of an LED.

martini · 04 January 2011, 18:17

12v led - check

Hightower · 04 January 2011, 21:40

Can you not check the voltage of the SRM Cable? I'm going to guess it's going to be 12v (I could be wrong) it seems unnecessary to have other voltages involved to me and it is a switching cable rather than a sensor cable. If it is indeed 12v I would doubt that the current draw from a single LED would overload the circuit. Could you not contact customer support to verify this as the simplest solution is often the best one.

Erin · 04 January 2011, 22:07

It's very unlikely it will be at 12v. In most cases a switch of this nature will be grounding a circuit to pull a transistor/ic on to activate the silent mode. Most ttl/cmos voltages are 5v or less in modern electronics, and extra load may stop the circuit working altogether or cause an overheat in a transistor due to too much current flow.

Hightower · 05 January 2011, 01:05

Quote:

Originally Posted by Erin

It's very unlikely it will be at 12v. In most cases a switch of this nature will be grounding a circuit to pull a transistor/ic on to activate the silent mode. Most ttl/cmos voltages are 5v or less in modern electronics, and extra load may stop the circuit working altogether or cause an overheat in a transistor due to too much current flow.

Would be worth checking though, as it would save some aggro.

martini · 05 January 2011, 08:23

TBH I'm more in favour of leaving well alone. Fitting a DP/ST instead of a SP/ST and taking a 12v supply for the LED from the adjacent switch is no effort at all.

9D280 · 05 January 2011, 13:10

If it's a toggle switch, what's wrong with using the big lever thing to tell you what it's doing?

martini · 05 January 2011, 14:41

Quote:

Originally Posted by PeterM

I love the ability to go into 'stealth' mode........

Now why would you want to ???

I can picture the scenario:
The usual crowd of rib groupies who wouldn't give you the time of day if you didn't own one calling me up for their free day trip to France: "Yeah sorry mate I've er..um..got a plumber coming round at 2, can't leave the house".

Next thing they're logged into marinetraffic.com watching you flit across their screen straight into the Bassin Vaubin

I love AIS, I think it's a great idea but I do like my privacy now & then too!

Erin · 05 January 2011, 16:14

Quote:

Originally Posted by martini

I love AIS, I think it's a great idea but I do like my privacy now & then too!

You can't go hiding from the public now that you're a fully fledged 'events manager'

martini · 05 January 2011, 16:35

Well spotted, wondered how long it would take!

Erin · 05 January 2011, 16:50

Nature of my job really. Need a keen set of eyes to spot the interesting bits.

martini · 06 January 2011, 17:53

Quote:

Originally Posted by martini

Got a couple on the way from Maplins now

Ordered 3pm Tuesday, despatched 4pm Wednesday, arrived in the post this morning