daft question on LED indicators and high VDC

[Clive S]

I've made a small PCB 62mm x 40mm, it's got a larger section of copper on the banded area, roughly 38mm x 40mm. Just ran some tests and it levels at around 56degC, so better than before, but not massively.

I do like the NUD chip, the issue is it's SMD (can't solder those) and for 68VDC and a single LED it's over it's power limit anyway. I guess I might have to get that 48W PSU anyway...

Cheers,
T.

BTW. I'm not limited for space, I've got loads:)

This is what you quoted [Those 7seg displays are pretty neat considering the voltage range on them. I'll have to stick with a small LED indicator as I'm tight on space as it is.] This is why I mentioned that ..Clive

[dsc]

Should've been more clear, I've got no space on the front panel, but loads in the guts, which basically means I need to stick with a single panel mounted LED and whatever internals it needs.

T.

[EddyCurrent]

I didn't think of using a voltage regulator at first, given the OP's requirements, but it's a good idea.

[Binary]

If its because the chip i mention is a smd can i say don't be frightened to try just make sure your not using a blow lamp to solder with, I have soldered these i.c.'s using a soldering iron, there are a few ways of removing the solder if you mess up, solder sucker for one, then check by running a stanley blade between the contact legs to make sure no "whiskers of solder is left".
Can i say if you can buy leds at a good price like Meeee. if your using the LED panel light which will have a resistor in using red leds as a zener could be good. Red LEDs have a 2.2 volt drop times this by 10 in series, yes you've got it 22 volts so 20 leds will give you 44 volt drop with your 24 volt panel light also in series your resistor in the panel light current limiting you leds you will have a 68 volt led ...and a lot of additional light ..but no heat
this is food for thought.

[Clive S]

I can see that your going to be another valuable member of this forum. ..Clive

[cropwell]

Most of the thinking seems based on 20ma current through the LED. It might be worth experimenting with resistor values that give about 5ma and see if the brightness of the LED is acceptable. So then a single series resistor would dissipate less power and could be a cheaper component.
.
Just had a play on the breadboard and LED in series with 4 x 4.7k ohm (18.8k) still gives a reasonable light. I tried it on 30v 15v and 5v (5v is probably too dim). I used a standard 3mm red in a clear capsule LED.