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Need some help with a circuit and don't know where to begin!

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New Member
Hi all,

I am new to this forum...and I hope I can get some help. I use to tinker with electronics, but I have been out of it for a long time now...and of course...I have forgotten everything!

This animation illustrates the circuit I want to build....

There is a larger version of it here...


Anyway, I need something that will make the lights illuminate in sequence as the needle swings up. Also, I have no idea what I need to use to make the needle swing. I assume it would be some sort of motor.

Any ideas or assistance would be greatly appreciated!


panic mode

Well-Known Member
Try sawtooth (or better triangle) oscillator coupled with
LM3914 and for needle, just use old galvanometer and
potentiometer to syncronize it with lights

Someone Electro

New Member
This is the simpelest project i ever sean!

Use a motor to move the handle and make metal plates to act like svitches(for light bulbs)!

There is no electronic neaded for this

The components you need for this:

-A motor whith reductor
-some sheat metal (can be alumimium foium) for contacts
-a housing

Easy to make the mehamism whith lego tehnic parts! :)


New Member
If I made contacts off the bulbs and the needle was the switch basically...wouldn't the lights turn of after the needle passes by? They need to stay on.


New Member
Hi Zandor,
Using Someone Electro's idea you could use diodes between each contact plate so that voltage would also be supplied to the preceding plate(s).
There would be somewhat lesser voltage to the preceding lights but it should work ok.

Good luck with it:)..........Tony

Someone Electro

New Member
Thats a good idea of using diodes

my idea was not to use a neadle to brush over the contacts i ment a half circle shaped plate so it brushes over all the contacts behind.

Whith my idea some light bulbs behind can light of for short time(like in the amimation) (if it isnt exsactly fiting the contact)

whith sikeers idea they all vill blink ast the same patern
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