/diy/ - Do It Yourself

[Anonymous No.628081]

Hello DIY.

How difficult would be for someone like me (0 electric/electronic skills) to make one of these?
All the lams I found are just too little.

[Anonymous No.628082]

A battery, a power switch, 3 pots with knobs, 3 resistors, an RGB led and an enclosure. Should be possible for a newbie, at least if you practice soldering a little beforehand.
If you want it to function exactly like the one in your pic, then more practice is needed.

[Anonymous No.628084]

>>628082

Nah, I don't need to look as in the picture, I just want to make my sel one bigger.
I have solded before, with a tin solder, at least.

But I don't think it could be that easy, the bar of colour that lamp has is to switch colours, it looks kinda hard.

I'll be back, I'm going to google what are pots with knobs and resistors.

[Anonymous No.628088]

>>628084
With three knob, you're "mixing" manually R G B color level.
The effect can be quite different.
eg:
Low R, Low G, Low B = Dim white
High R, High G, High B = Bright white

But yeah, the easiest is like the one post above.
If you want similar effect like in OP pic, you'll need microcontroller.

Basically, use PWM and divide duty cycle to 3 parts.
eg: if R duty cycle is 50%, you're left with 50% for G and B.
Modifying the knob will change this duty cycle ratio.

[Anonymous No.628100]

>>628081
buy finished rgb led-strips instead.

[Sage No.628102]

>>628088

I think it will be better to not even try, i do not even understand what you are telling me.

[Anonymous No.628103]

what is a lam?

[Anonymous No.628108]

>>628102
you need three different LED's per actual "pixel", a green a red and a blue one. you can buy these led's which have three colors alreadyin them, "RGB-led" which makes it easier.

then you need to mix those three colors to get another color ( like painting, but different combninations)

so you need a microcontroller ( like an arduino ) to control the levels of each color on each LED to get the right colors eventualy !

what you need: the box to put it in, a powersupply, enough LED's, resistors and if you use a lot of LED's, transistors so you can use a bigger powersupply than the one in the controller has.

don't give up, it's not that hard but there's a lot to learn

[Anonymous No.628112]

>>628103

a mistake I made when I was writing lamp

[Sage No.628132]

>>628108

only the arduino is more expensive than the lamp in the picture.
Thanks for the information but I think this is a bad project and I don't have the skills.

[Anonymous No.628138]

>>628132
if you do not know a lot about controllers and programming you can start of with some simple circuits, using LED's and stuff ! you will come across some IC's and programming eventually... cheers

[Anonymous No.628181]

OP, do you actually want a touch bar that sets the color based upon where you touch it, and that is designed around a prism spectrum (rainbow spectrum)?

What the other posts are suggesting is, just use three knobs that you turn to set the color. If you would be ok with this, it's really pretty easy.

If you want that sort of rainbow touch control, then yeah, it's a little harder, but not much.

Google "rainbow rgb algorithm" or "spectrum rgb algorithm" for code samples that will approximate it.

[anus presley No.628212]

you dont need an Arduino to light some LEDs, FFS. this simple circuit will give you infinitely-variable color from an RGB LED.

[Anonymous No.628218]

>>628212
>Using transistor
>Not connecting resistor to pot and to LED directly.

Read
>>628082

The reason why/when you need microcontroller.
>>628088

[Anonymous No.628220]

> >Not connecting resistor to pot and to LED directly.

the transistors are used as a very low cost current multipliers. without them, you'd need to buy special high-power pots coz regular cheap pots would start to smoke at the high end.

[Anonymous No.628227]

>>628220
That circuit is stupid anyway.
For high power, limit the current at base, so that
Ic = hfe x Ib
and bias the transistor to operate at linear region.
Else, you're wasting power for no reason at current limit resistor.

[Anonymous No.628241]

>For high power, limit the current at base, so that Ic = hfe x Ib

given this configuration, base current is already naturally limited to about 1% of the load current (or Ic/hfe)

>and bias the transistor to operate at linear region.

the pot allows 100% freedom: the transistor can be cut off, in it's linear region, or completely saturated, as per the users' needs.

> Else, you're wasting power for no reason at current limit resistor.

and so what? the OP is a complete noob. he needs something simple, not something insanely efficient.

[Anonymous No.628293]

>>628212
>NPN
>High-side switching
Oh, please.
To turn on that LED you'll need Vb > Ve
But your Ve are really close to Vcc as load is at emitter.
Most people will suggest you'll need Vcc + 0.6V at Vb for this kind of configuration.
This circuit won't work.

Connect the LED and resistor at collector, and it should works as expected.
This will be a low side switch aka common emitter.
High switch aka common collector usually used with PNP.

[Anonymous No.628335]

>Connect the LED and resistor at collector, and it should works as expected.

geez, I just finished schooling one retard, when another one shows up.

if you put the load on the collector, then you get essentially an ON-OFF switch. below 0.7V, the transistor is cut-off, and above it, it becomes saturated. this is obviously not what you want, if you want to have an infinitely-adjustable voltage on the LEDs.

[Anonymous No.628336]

>Connect the LED and resistor at collector, and it should works as expected.

if you put the load on the collector with an NPN, then you get essentially an ON-OFF switch. below 0.7V, the transistor is cut-off, and above it, it becomes saturated. this is obviously not what you want, if you want to have an infinitely-adjustable voltage on the LEDs.

if you use a PNP with the load on the high side, then you get precisely the same characteristic transfer function as with the circuit shown above, except it gets brighter when you turn the pot the other way.

[Anonymous No.628458]

>>628336
>below 0.7V, the transistor is cut-off, and above it, it becomes saturated
It would need another resistor between pot and Vcc.

As in circuit >>628212, it does work but the transistor only ON once Vb exceed Vf LED.
If he put LED at collector and resistor at emitter, it'll be more linear.

http://electronics.stackexchange.com/questions/57845/why-would-one-drive-leds-with-a-common-emitter

[Anonymous No.628463]

>>628458
>transistor only ON once Vb exceed Vf LED.
*LED turn ON once Vb exceed Vf LED.

[Anonymous No.628471]

>>628293
>>628336
>>628458
>>628463
Hopefully this will clear everyone confusion.

[Anonymous No.628520]

>It's a me, OP!
>"I don't know shit about electronics"
>give up without even trying und sage the thread
>come back the day after.
>read posts about some fight between people talking about circuits und shit.
>don't understand a think.
>mfw I just wanted to make a lamp

[Anonymous No.628522]

>>628520
RGB LED controller from China are around $3.
It can change color, pattern, etc.