Disco Table project vid2

Done! All 6x6 LEDs on the breadboard, ready to develop some kewl visual patterns.
24mA forward current * 36 LEDs = 864mA. My PSU says its claiming upwards of 800mA or more so is about okay. The 5v regulator is getting warm and making some interesting burning smells, despite the heatsink - need a bigger one plus maybe a fan. The regulator is rated at 1.5A so it should be suitable.
PSU is set at 12v, I'm thinking of feeding it with 9v or maybe 6 or 7 instead, (lowest I can get away with a 7805) perhaps it'll not get so hot. Anybody know anything about linear regulators?

Category:

Science & Technology

Tags:

• disco
• table
• diy
• electronics
• project
• LED
• prototype

[NotReallyFailure]

Voltage regulators get hot, it's normal I guess.

[H3liosphan]

@NotReallyFailure

The smell was most certainly not normal, it was definitely running too hot.

I found some computer RAM heatsinks, sawed off a small section, drilled a hole and screwed it onto the regulator, now its running nicely! ;-)

[FungryMan]

what's the input voltage on the reg?

[H3liosphan]

About 9v from a spare wall transformer I had lying around. Glad to answer such an abrupt question!

[FungryMan]

well that 7805 will get a little warm but not harmful at all with a small heatsink. is yours heatsinked? I built a psu the outputs 12 and 5 volts from 19 volts. I used the 7805 and the 7812 and I had to put quite a heatsink on the 7805 but that's a bigger voltage difference than you have.

[H3liosphan]

Yes I have a small heatsink I took off a dead graphics card memory chip, cut to size & drilled. You're right, the chip & heatsink are too hot to touch when running, but it solved my overheat cut-outs.

I always found the best solution if you need 12v and 5v is to just salvage an old PC power supply. I know they're bulky as hell, no use for 'mobile' electronics, but they're more efficient than regs, and can be small if taken from olde laptops! My homebuilt house alarm uses a PC power supply.

[SigSharpeSolutions]

@H3liosphan I'm also using an LM7805 as a voltage regulator. I needed more current, so I'm using a 12V 2Amp power supply. The regulator gets pretty hot, especially because regulating from 12V to 5V is a lot of work for a linear regulator. As long as you dont pull more than 1.5A for a long time it should be fine, they have built in thermal shutdown circuits. You can look into using a switching regulator, they're more efficient, but a bit pricey. Keep up the good work!

[NotReallyFailure]

@H3liosphan Cool.

What would happen if you put two voltage regulators into same pins, parallel like? Would't electricity divide into two of those?

[FungryMan]

I did my psu as a project but yeah I agree. I use a 580 watt psu I modded to power a car amp for the subs in my room. I have a video of it. Switchmode power supplies are a LOT smaller and very power efficient..