Model Boat Mayhem - Forum

Technical, Techniques, Hints, and Tips => The "Black Arts!" ( Electrics & Electronics ) => Topic started by: tjones27 on November 14, 2011, 12:37:56 PM

Title: Wiring up LED's, but not what you think
Post by: tjones27 on November 14, 2011, 12:37:56 PM
Hi,
im trying to wire up some LED's, but not in the normal way. bascically i have these strips of LED's that run off of 12 volts. i want to wire up 4-7 strips of these, and i understand that i need to wire them in parallel. now the problem comes. i want to use a switch that will start from the off position. at the first click, i would like one strip of lights to come on, when i then move the sliding switch further, i would like the 2nd strip to come on, then move it further and the 3rd strip to come etc. i was thinking of a linear slider, but i know that only works for filament bulbs.  {:-{ a very simple way i came up with (ima  great fan of K.I.S.S.) but maybe lots of micro switches so that as you move the slider it turns on one circuit, and then as the slider moves further to along it pushes down the next micro switch to create the next circuit etc.

does anybody firstly know what i mean? but more importantly does anybody know of a gizmo, or an already existing product that would be simple to modify to do the job that i need it for. or whould i jsut stick with many micro switches. any help would be greatly appreciated.

Regards Tj
Title: Re: Wiring up LED's, but not what you think
Post by: barriew on November 14, 2011, 12:55:06 PM
Does it have to be a slider? You should be able to find a suitable rotary switch.

Barrie
Title: Re: Wiring up LED's, but not what you think
Post by: tjones27 on November 14, 2011, 01:18:02 PM
i suppose it could be a suitable rotary switch which could be geared. is there something that exists as a rotary switch?
Title: Re: Wiring up LED's, but not what you think
Post by: Guy Bagley on November 14, 2011, 01:29:57 PM
i reckon Dave at action may have something suitable- he has so many great gizmos available.... led strips are relatively low current draw so i guess you should be ok with a small unit of some type ?
Title: Re: Wiring up LED's, but not what you think
Post by: Rex Hunt on November 14, 2011, 02:38:59 PM
micro switches switched by a snail cam seem to be the simplest idea I could come up with!

Rex
Title: Re: Wiring up LED's, but not what you think
Post by: Netleyned on November 14, 2011, 03:35:06 PM
What sort of time sequence is needed
Is the effect you are looking for a ripple
or do you want a time delay depending when you hit the
next switch?
The effect you want to achieve will dictate whether to go
Electro Mechanical or Electronic


Ned
Title: Re: Wiring up LED's, but not what you think
Post by: tjones27 on November 14, 2011, 03:52:05 PM
What sort of time sequence is needed
Is the effect you are looking for a ripple
or do you want a time delay depending when you hit the
next switch?
The effect you want to achieve will dictate whether to go
Electro Mechanical or Electronic


Ned

the effect that im after is like using a dimmer switch on a filament bulb, but instead of dimming the LED's, i just want to be able to have more on or off. so at the first stage of the switch being on, one strip is lit. then at the next stage two strips to be on. so at the end of switch all strips will be lit. and then in the reverse order so 7 are all on at once, and then at the final stage just one strip to be lit, until you slide the switch to the off position for all the strips to be off. hope this makes sense.


Tj
Title: Re: Wiring up LED's, but not what you think
Post by: barriew on November 14, 2011, 05:25:14 PM
I'm still not clear if this is a manually operated switch or one controlled from the R/C equipment. The rotary control I suggested is for manual operation.

Barrie
Title: Re: Wiring up LED's, but not what you think
Post by: RaaArtyGunner on November 14, 2011, 08:08:15 PM
Would it be possible to operate a "rotary switch" using a servo, much like a rudder control. ?
Title: Re: Wiring up LED's, but not what you think
Post by: Tug-Kenny on November 14, 2011, 08:42:08 PM
Most rotary switches  'click'  between moves, so you could always remove  (or reduce the pressure) on the mechanism.


ken

Just wondered what the lights were for .............   8)
Title: Re: Wiring up LED's, but not what you think
Post by: Corposant on November 14, 2011, 09:48:26 PM
Tj

My approach would be to use a rotary wafer switch driven by a servo. Unfortunately there is a bewildering array of options! e.g.

http://uk.farnell.com/jsp/search/results.jsp?N=0&Ntk=gensearch&Ntt=rotary+wafer+switch&Ntx=mode+matchallpartial&suggestions=false&ref=globalsearch&_requestid=271553&isGoback=false&displaytext=&isRedirect=false

As Ken says, you can miss out the click mechanism. Makes for an interesting soldering execise! You do not say how much space you have available. If this is limited, an electronic approach may be more appropriate - outside my sphere of experience I'm afraid!

Mike
Title: Re: Wiring up LED's, but not what you think
Post by: Netleyned on November 15, 2011, 08:17:17 AM
Most rotary switches click because of a ball bearing that the wafers ride over as the switch turns
Taking the out gets rid of the click and the pressure but leaves the switch a bit vague in operation

Ned
Title: Re: Wiring up LED's, but not what you think
Post by: tjones27 on November 15, 2011, 08:30:26 AM
Thnaks for all of the advice and options guys, its much appreciated. sorry, i should've said what its for. my missus is doing project design at university and for her final year she has to design a light as a minor project. (sadly she knows nothing about electronics and my knowledge is fairly limited) so she is doing a wave light in which she wants to have strips of LED's to light up when pushing a part of the base of the wave. there is quite a bit of space available in the base of the light. Mechanical switching does seem to be the most straight forward, but electronic is much more space saving. i suppose a rotary wafer switch could be geared so that you can use a slider to turn the switch if that makes sense. i will try and get her to send me some drawings of what she is trying to do so you can all see.
Title: Re: Wiring up LED's, but not what you think
Post by: malcolmfrary on November 15, 2011, 10:40:36 AM
The way they always used to do that kind of thing at Blackpool Illuminations was an array of motor driven rotary switches. 
Using DC, and mixing the rotary switches with diodes to combine outputs from the switch selectively, there are a heck of a lot of combinations and permutations available when offering power to sticks of LEDs.
Most rotary switches came with a combination based on 12 - 1 pole, 12 ways; 2 poles 6 ways; 3 poles, 4 ways; 4 poles 3 ways etc.  It is possible to get kits to stack wafers, as well.  Just needs more muscle to move them.  Arranging one to work with a linear slider could be a tricky proposition, gearing a motor to the switch would be easier.  Double reduction worm springs to mind, much like a motor driven tuning condenser that I got when but a lad from one of those wonderful govt surplus shops that were around back then.
Title: Re: Wiring up LED's, but not what you think
Post by: More Coffee on November 18, 2011, 01:19:37 PM
There are a couple of options..
First the LM3914 bar/dot LED driver and a simple circut using a servo turn a potentiometer,or a 5K ohm pot on the transmiter to run a pulsewidth converter to to vary the input on the LM3914 to turn your leds on of as desired..

http://www.national.com/ds/LM/LM3914.pdf


The easyiest way is a Cam Switch..So simple it will blow your mind.

(http://www.amci.com/tutorials/images/mechanical-limit-switch.gif)
Title: Re: Wiring up LED's, but not what you think
Post by: Rex Hunt on November 19, 2011, 05:49:09 PM
There are a couple of options..
First the LM3914 bar/dot LED driver and a simple circut using a servo turn a potentiometer,or a 5K ohm pot on the transmiter to run a pulsewidth converter to to vary the input on the LM3914 to turn your leds on of as desired..

http://www.national.com/ds/LM/LM3914.pdf


The easyiest way is a Cam Switch..So simple it will blow your mind.

(http://www.amci.com/tutorials/images/mechanical-limit-switch.gif)
cam switch is almost what I meant!
a single helical cam operating a series of microswitches as it turns.

Rex
Title: Re: Wiring up LED's, but not what you think
Post by: malcolmfrary on November 19, 2011, 07:37:19 PM
One cam working a bunch of switches is heading for complexity - one switch per bank of lights and one cam per switch is the simplest way to go.
Otherwise you head for the learning curve of integrated circuits, and the wonders of counter chips and decoders and drivers.
Title: Re: Wiring up LED's, but not what you think
Post by: nick_75au on November 20, 2011, 09:31:23 AM
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=12615

Does exactly what you want off a spare TX channel. a switch channel will work

Nick
Title: Re: Wiring up LED's, but not what you think
Post by: malcolmfrary on November 20, 2011, 11:00:55 AM
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=12615

Does exactly what you want off a spare TX channel. a switch channel will work

Nick
Its not for a boat, nor is it RC, see reply #12.
If it needs to be motorised, the cam arrangement is the simplest.  It would probably work well manually with a knob on the end of the shaft (in the words of the song about the wizards staff), or it could be hooked to a linear slider much like a radio dial, only in reverse. 
Title: Re: Wiring up LED's, but not what you think
Post by: nick_75au on November 21, 2011, 04:04:54 AM
Opps :embarrassed:

Nick
Title: Re: Wiring up LED's, but not what you think
Post by: funtimefrankie on November 21, 2011, 05:07:59 PM
http://www.youtube.com/watch?v=VzIXvO6RahQ

 :-))

http://www.youtube.com/watch?v=3pXQ-vdg1C8&feature=related
Title: Re: Wiring up LED's, but not what you think
Post by: Captain Flack on January 15, 2012, 07:35:05 PM
I have the Hobby King Multi switch.  It is capable of switching in lots of different sequences. Brilliant piece of kit. :-) :-) :-) :-)