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/diy/ - Do It Yourself

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441221 No.441221 [Reply] [Original]

Help me out /diy/!
Want to switch between two LED lights with one of these:
>ebay.co.uk/itm/AC-16A-250V-20A-125V-6-Pin-Terminals-DPDT-ON-OFF-ON-Boat-Rocker-Switch-/300828310898?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item460ac3bd72

What do to?

>> No.441225

selfbump

>> No.441224
File: 27 KB, 515x449, led switch.png [View same] [iqdb] [saucenao] [google]
441224

>> No.441226

>>441224
so all the +'s have to connect to one side on the DPDT, and all the -'s should be connected?

>> No.441228

bampp

>> No.441230

>>441224
also: a SPDT would do it. 16-20A is overkill, 1 Amp rating is plenty

SPDT = single pole double throw
DPDT = double pole double throw (basically 2 SPDT's in one)

>> No.441231

>>441226
correct. the middle one is the common that switches between the 2 outer ones, so the middle one goes to the power

>> No.441234

So you are building a device that will choose which of two LEDs you will quickly burn out.

>> No.441245

>>441234
cut me some slack

>> No.441247

You will need a resistor in that circuit, or the LEDs will burn out.

>> No.441248

>>441247
is a resistor always necessary when working with LED strips?
I've already put up a few in the rehersal room without the DPDT in between and they seem to be working fine

>> No.441249

Given that the average LED has a max current of around 30 miliwatts, and a voltage drop of around 1.5 to 2 volts, you will need a 1k resistor

>> No.441252

>>441249
I only know the LED Strips work with 12v

>> No.441254

>>441248
If you are working with components that have a built in resistance, then you are fine. But if it is just an PN junction, it is a matter of time on how long until it dies. The only thing limiting the current from being infinite is the tiny pn junction.

The only way to know for sure is to look at the component sheet. just google the model number you find on the component. What OP drew looks like your typical LED though

>> No.441258

>>441252
The link you posted is dead so I have no idea.

>> No.441266

>>441258
That is the DPDT, just insert www.
the LEDstrips are something like this
http://www.ebay.co.uk/itm/5M-500CM-3528-red-300Led-SMD-Flexible-Lamp-Light-Strip-12V-DC-/140960862262?pt=US_Car_Lighting&hash=item20d1ec1036

>> No.441269

>>441249
>max current of around 30 miliwatts
OP, don't listen to this anon. He can't get his units right, nor his numbers. As an engineeringfag, this drives me crazy.

LED current varies with the color choice. If my memory is right, red LEDs will draw around 25mA, while blues are around 15mA. If you assume 20mA, that's a decent assumption. Even if one does burn out, it's really easy and cheap to replace.

The data sheet for the LEDs will tell you exactly what the forward voltage drop and current restrictions are.

Here, there are really simple equations to figure out what resistance you need, but this calculator will do it for you quickly: http://led.linear1.org/led.wiz

>> No.441311
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441311