Resistor on illuminated switch but without dimming the circuit LEDs??

[thunderbollocks]

Hi guys.

As much as I like figuring things out for myself, this one has got me beat!

Right. This is probably very basic for nearly all of you but I'm trying to wire up some LED DRLs on the car with some of those pretty LED illuminated latching switches..........
..........like these

Now, these are supposed to be for use in 12v applications but when I have applied my light testing battery box with a 9v battery inside, the LED's inside of the switch blow!
So I thought, "OK, resistor!". Great! A little dimmer, but doesn't blow the switch illumination. Fine.
So then I mock up the rest of it by following this..........


So I've got my LED light strip positive to NC1 / + / brown,
LED negative to - / ground / black,
9v battery positive to C1 / red with resistor in line,
9v battery negative to - / ground / black

Press the latching switch on, on comes the illuminated switch LED and on comes the LED's on the strip that I was aiming to switch on. Great, It all works!
The issue I have is though (and I know most of you know exactly what I'm going to say), even though I have over come the issue of blowing the LED in the switch by placing a resistor in line, now my LED's on the strip are not bright enough :-C

So. Firstly let me just be clear, am I wired up correctly?
And secondly, how can I stop the LED in the switch from blowing at 12v but keep the LED's on the strip as bright as they should be??

There is a question I want to ask about wiring up so that maybe the LED in the switch is constantly on but dimmer/brighter when the button is pressed off/on respectively. If this can be answered in the same swift stroke, then I will be even more so appreciative



Thanks in advance for any useful info guys

 

[Bluejets]

So. Firstly let me just be clear, am I wired up correctly?
And secondly, how can I stop the LED in the switch from blowing at 12v but keep the LED's on the strip as bright as they should be??

No...wiring is incorrect.
Can you provide a spec sheet for the switch?
Then maybe we can help.

 

[thunderbollocks]

Thanks for your reply Bluejets.
Does this help?

Material
Contact Silver alloy
Button Nickel plated brass / Stainless stell
Enclosure Nickel plated brass / Stainless stell
Base PA66
Mounting hole size ф16mm
Switch combination 1NO 1NC
Operation types Resetable
Head shape Flat
Lamp type Ring luminated
Degree of protection IPP67, IK10
Tail configuration Connection terminal(1.8x0.4mm)
Switch specifications 5A/250VAC
Contact resistance ≤50mΩ
Insulation resistance >1000mΩ
Dielectric intensity 2000VAC
Ambient temperature -20℃~+55℃
Machanical life 500,000 cycles
Electrical lif 50,000 cycles
Panel thickness 1~10mm
Nut torque 5~14Nm
Operation pressure About 3~5N
Operation stroke About 2.5mm
LED life 40000 hours
LED Color Blue/Red/Green/Yellow/White/Orange

 

[thunderbollocks]

Sorry Bluejets, I think this is the spec of the actual switches. The spec above was for a similar one

Technical Specifications
Rated Voltages (DC): 6V/12V/24V
Rated Volatges (AC): 100-110V/220-240V
Power Rating: 3A
Mechancal Life: 500,000 Cycles
Electrical Life: 50,000 Cycles
LED Life: 40,000 Hours
And below are pictures of the ACTUAL switches I have in my posession

 

[Bluejets]

I was refering to a possible schematic of how the internal connections are made.
i.e. whether or not the switch contacts are isolated from the LED connections.

If so, then refer to diagram.

 

[thunderbollocks]

No, I'm afraid not mate.
I can see if I can dig something up on the internet bit it may not be exactly these switches as these came off eBay, probably some cheap Chinese things.
I do, however, have ones of the same switch. What if I attempt to deconstruct one and forward on some internal pics? Would that help at all?

It'll give me an excuse to take something apart anyway. Taking stuff apart is my fave

 

[KTW]

NO to + to lights
C1 to + battery
battery - to - to lights
I tried to post a diagram but it fails for some unknown reason.
Do you have a link to where this was purchased?

 

[Bluejets]

Just meter out the connections.... No need to go wrecking the switch.

 

[thunderbollocks]

NO to + to lights
C1 to + battery
battery - to - to lights
I tried to post a diagram but it fails for some unknown reason.
Do you have a link to where this was purchased?

Cheers KTW, most appreciated.
And will that overcome the switch illumination LED blowing?

 

[thunderbollocks]

Just meter out the connections.... No need to go wrecking the switch.

Sorry Bluejets, what do you mean by "meter out the connections"?

 

[KTW]

Cheers KTW, most appreciated.
And will that overcome the switch illumination LED blowing?

That's how this five pin 12 volt switch is normally wired to a 12vdc battery.
Do you have a link to where this was purchased?

 

[KTW]

Bluejets

 

[thunderbollocks]

Do you have a link to where this was purchased?

I don't mate. I bought them quite a while ago on eBay. I have looked through my purchase history but it looks like I bought them longer ago than my history will go back to.
There are loads of other sellers selling them too, which are probably the same but I couldn't guarantee that they would be 100% exactly the same.

What other information do you need? If you need any further info, I'll do the leg work for you mate. That is, unless, you would prefer to see for yourself as you know what your looking for

 

[KTW]

Did you wire it this way?

 

[Bluejets]

That's how I thought it would be and wire as per #5 but I guess no one liked that drawing.

 

[Pyramid]

Did you wire it this way?

I think this is what you are trying to do?



The resistor between NO and the + input to the LED is computed for 10mA with a 13.6V battery. The forward voltage drop on white LEDs is ~3.6VDC, so that leaves 10V across the resistor at 10mA=1000 Ohms.

 

[KTW]

The resistor might be built in, it doesn't mention anywhere that I have seen that the switch requires a resistor to protect the led within the switch.

 

[Pyramid]

If you want a dim LED when the load is off and normal LED when the load is powered on, then try this:


Make the resistor connected to the NC terminal several times higher than the NO resistor. LEDs don't dim very well by changing the current so you may have to play with this value to get the result you like (the proper way to dim an LED is by changing the duty cycle of a pulsed DC stream powering it). The diode on the NO resistor is a type 1N914 or similar and is needed to prevent the NC resistor from powering the load through the NO resistor.

 

[Pyramid]

The resistor might be built in, it doesn't mention anywhere that I have seen that the switch requires a resistor to protect the led within the switch.

If you're blowing up LEDs with a 9V battery, I'm guessing the switch does not include the dropping resistor. One of the reasons they don't include the resistor is that you can tailor the switch to the voltage it will be used with (the resistor will change depending on the supply voltage, per the formula in my 1st reply).

 

[Herschel Peeler]

Thanks for your reply Bluejets.
Does this help?

Material
Contact Silver alloy
Button Nickel plated brass / Stainless stell
Enclosure Nickel plated brass / Stainless stell
Base PA66
Mounting hole size ф16mm
Switch combination 1NO 1NC
Operation types Resetable
Head shape Flat
Lamp type Ring luminated
Degree of protection IPP67, IK10
Tail configuration Connection terminal(1.8x0.4mm)
Switch specifications 5A/250VAC
Contact resistance ≤50mΩ
Insulation resistance >1000mΩ
Dielectric intensity 2000VAC
Ambient temperature -20℃~+55℃
Machanical life 500,000 cycles
Electrical lif 50,000 cycles
Panel thickness 1~10mm
Nut torque 5~14Nm
Operation pressure About 3~5N
Operation stroke About 2.5mm
LED life 40000 hours
LED Color Blue/Red/Green/Yellow/White/Orange

It doesn't give a resistor value. I think we can assume there's not one. How much brightness do you want?
Dim, 5 mA, 2,000 ohms at 12 V
Full, 20 mA, 510 ohms
In between, 10 mA, 1,000 ohms