Can i use a 200k ohm resistor to light an led ?

I have no resistor other than the 200k ohm one, so what will happen if I connect that one to the LED ?

Probably nothing will happen, you are not giving it too much current.

Maybe if you put 20 resistors in parallel it might glow a bit dim. A lot depends on the actual LED you have.

Grumpy_Mike:
Probably nothing will happen, you are not giving it too much current.

Maybe if you put 20 resistors in parallel it might glow a bit dim. A lot depends on the actual LED you have.

I soldered a 10k to one of my boards instead of a 1k. I have to shade the LED to have any hope of seeing it. Any amount of ambient light completely overpowers it.

Be ok if you have a 1kV dc supply - but it would get rather hot (5W dissipation).

Allan

Not an issue. Just solder 200 of them in parallel, that should do it.

Jiggy-Ninja:
I soldered a 10k to one of my boards instead of a 1k. I have to shade the LED to have any hope of seeing it. Any amount of ambient light completely overpowers it.

I had a 10k on a high efficiency blue LED. It was almost too bright to look at, and visibly lit the ceiling at night. It depends on the LED.

How would one make a say 100 ohm - 1000 ohm resistor out of things found at home?

Johan_Ha:
How would one make a say 100 ohm - 1000 ohm resistor out of things found at home?

For the exploration of it, just drawing filled in rectangles on paper with a lead pencil will create a resistor when you stick contacts on the ends.
But there is no reason whatsoever to not have an assortment of resistors when they're a penny per.

If you are serious about this stuff, buy an assortment to have on hand.
If you are not serious about this stuff get another hobby.

.

nityoday:
I have no resistor other than the 200k ohm one, so what will happen if I connect that one to the LED ?

Nothing. Perhaps if you add a power source as well some light will be produced, about 1000 times
less light than for a 200 ohm resistor.

A higher voltage supply could compensate for the high resistance, but thats rather impractical way
of dealing with a shortage of more reasonable resistor values, and 5000V is rather dangerous and your
resistor is unlikely to be rated for 125W power dissipation I suspect :slight_smile:

Johan_Ha:
How would one make a say 100 ohm - 1000 ohm resistor out of things found at home?

Try a pencil lead? Shave both ends (unless its a propelling pencil!) and add croc-clips.

I think that resistance goes up with lead hardness, so 2B conducts better than HB which is
better than 2H etc etc.

Do they still make old-fashioned pencils in different hardnesses these days even?

Cut off a stranded mains power cable. tease apart all the strands and string them together until you get 1000 ohms.

Assuming you’re in the US - $5.36, free shipping, and ships from within the US

Is it really that hard to get a resistor kit? (for $10-20, you can get much nicer selections). Capacitor kits are about the same price.

Really worth it to have the right parts for the job on hand, instead of having to scrounge - consider that you’re scrounging to replace something that costs a penny!

When you’re cracking apart a 25 cent pencil to use the lead in place of a 1 cent resistor, you’re doing something wrong.

DrAzzy:
When you're cracking apart a 25 cent pencil to use the lead in place of a 1 cent resistor, you're doing something wrong.

Ah, but you can make a variable resistor with the pencil, and you can still write with it! Can't do all that with a regular resistor, can you? :stuck_out_tongue:

f you are serious about this stuff, buy an assortment to have on hand.

When I was a lad back in the 60's( Violins, please) the only way I could get components was to take old valve tv's apart.

I think I still have a few eg beehive capacitors from those days.

Allan

Good old days, you can keep them :wink:

Agreed - but it got me started.

Allan

nityoday:
I have no resistor other than the 200k ohm one, so what will happen if I connect that one to the LED ?

The LED will definitely light up. You just need to apply maybe around 2000 Volt DC across the resistor and LED combination. But would need to be careful of the high voltage, and would not be recommended due to such high voltage.

Alternatively, via ebay, get some resistors in the 330 Ohm region...... for 5 Volt DC.

Southpark:
You just need to apply maybe around 2000 Volt DC across the resistor and LED combination. But would need to be careful of the high voltage, and would not be recommended due to such high voltage.

...and you would need a 20W resistor.

I bought the kits from amazon, but the issue is they give you a lot of resistors and you run out of the ones you use... I just went to mouser and ordered 1000 each of the most common ones... at that qtd you get them for a penny a piece or less...