Red flickering led run from 2 AA batteries

KeithT said:
Oops! Yes I DO have it wrong!!
I have a multimeter.

First check on DC Volts that the red wire is positive! I made an assumution that this is so, but you never know?

Then disconnect at least one LED lead from your wiring.

Use the OHMS setting on your meter, and measure across the leads with the negative (black) lead on the 'flat' lead, you should get a near to zero reading.

Then swap the meter leads about, so that the positive (red) lead is on the 'flat' and you should get a high reading.

Basically, you are confirming the LED conducts electrickery in one direction only(LED = Light Emitting DIODE). If you get a zero (short circuit) or a high reading (open circuit) in both directions, then your LED is kapputten....
 
Gizzy said:
KeithT said:
Oops! Yes I DO have it wrong!!
I have a multimeter.

First check on DC Volts that the red wire is positive! I made an assumution that this is so, but you never know?

Then disconnect at least one LED lead from your wiring.

Use the OHMS setting on your meter, and measure across the leads with the negative (black) lead on the 'flat' lead, you should get a near to zero reading.

Then swap the meter leads about, so that the positive (red) lead is on the 'flat' and you should get a high reading.

Basically, you are confirming the LED conducts electrickery in one direction only(LED = Light Emitting DIODE). If you get a zero (short circuit) or a high reading (open circuit) in both directions, then your LED is kapputten....

Hi Gizzy
Many thanks for the above info.
Unfortunately, I think I have pushed my eye too far for the moment. It is only 5hrs since I had the injection and I probably ought not to be using the PC!
I will check the LED as soon as my vision improves (tomorrow?) and report back.
Meanwhile, fingers crossed!
 
KeithT said:
Gizzy said:
KeithT said:
Oops! Yes I DO have it wrong!!
I have a multimeter.

First check on DC Volts that the red wire is positive! I made an assumution that this is so, but you never know?

Then disconnect at least one LED lead from your wiring.

Use the OHMS setting on your meter, and measure across the leads with the negative (black) lead on the 'flat' lead, you should get a near to zero reading.

Then swap the meter leads about, so that the positive (red) lead is on the 'flat' and you should get a high reading.

Basically, you are confirming the LED conducts electrickery in one direction only(LED = Light Emitting DIODE). If you get a zero (short circuit) or a high reading (open circuit) in both directions, then your LED is kapputten....

Hi Gizzy
Many thanks for the above info.
Unfortunately, I think I have pushed my eye too far for the moment. It is only 5hrs since I had the injection and I probably ought not to be using the PC!
I will check the LED as soon as my vision improves (tomorrow?) and report back.
Meanwhile, fingers crossed!

No worries mate?

Had to go to A&E myself to get my peepers washed out last week, so I know how you feel!

Let me know via a PM how you get on when you feel up to the task....
 
Hooray!
Now that I can just about see what I am doing I resoldered the ''errant'' LED - THE CORRECT WAY ROUND and guess what?
It works! :bigsmile: :bigsmile:

Thanks everyone for the advice. :thumbup:
 
Hi Keith.

Some few months ago, I purchased the "Welder" kit, complete with a white flickering LED, and battery box, for 2AA batteries from 'Modeltown', I think it was about £16.00.

I painted the LED red, to simulate a fire in a pot bellied stove, in a signal box - very effective.
 
newboydave said:
Hi Keith.

Some few months ago, I purchased the "Welder" kit, complete with a white flickering LED, and battery box, for 2AA batteries from 'Modeltown', I think it was about £16.00.

I painted the LED red, to simulate a fire in a pot bellied stove, in a signal box - very effective.
This kit, also from Modeltown, now comes with a red LED to simulate a fire grate under the boiler.
 
KeithT said:
Hooray!
Now that I can just about see what I am doing I resoldered the ''errant'' LED - THE CORRECT WAY ROUND and guess what?
It works! :bigsmile: :bigsmile:

Thanks everyone for the advice. :thumbup:

Well done mate!

My peeper problems flared up again this weekend, and I had to go back to A&E, so I've only just caught up with this....
 
Gizzy said:
KeithT said:
Hooray!
Now that I can just about see what I am doing I resoldered the ''errant'' LED - THE CORRECT WAY ROUND and guess what?
It works! :bigsmile: :bigsmile:

Thanks everyone for the advice. :thumbup:

Well done mate!

My peeper problems flared up again this weekend, and I had to go back to A&E, so I've only just caught up with this....

Gizzy I hope the treatment is successful but don't put up with anyone messing you about. Eyes are too precious. If you have a known problem check on the Internet for symptoms and treatment. Then ask, repeatedly if necessary, for that treatment and the reason why if they don't apply it.
My problem displayed classic symptoms and yet 4 doctors at my local Teaching Eye Hospital failed to diagnose it for over 12 months. As a result what could have been a treatment which 12 months ago restored me to full vision is now compromised and I will only have partial restoration - at best.
 
ntpntpntp said:
Have you noticed those cheap LED tea-lights that have appeared in the last few years? They have a pleasing flickering effect, and if you dismantle one it has a tiny chip that drives the flickering. I read somewhere that some of these designs actually use a chip that's supposed to play a tune, and if you connect a small speaker across the LED you can hear it!

I've just taken the circuit board out of a singing birthday card and replaced the speaker with an orange led then soldered a red led to the battery tracks. Flickering beautifully :bigsmile:
About two quid,about two minutes of soldering.......Nice one Nick!!
Colin
 
Excellent, Colin! Those tuneful Christmas cards drive me bonkers, but I really hate to throw them away with all that electronickery and batteries in them.
 
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