sammy004

Hi guys I was working on a dimmer here and I was kinda stuck on how to hook up the 50K pot. I did easy circuits before and I have no training in this field what I know is from the wold wide web. Now I'm kinda stuck on how a pot works, see this is the curcuit I'm working on....

and this is how I have it hooked up but it keeps the light on the whole time it does not dim can someone please tell me what I am doing wrong.

blueroomelectronics

Do not connect a solderless breadboard to 110VAC or you'll invent fire. Bare wires = danger and possible more fire.
Solder, insulation and HV skills will keep you safe and alive.
Plus that's a logarithmic volume control, not what you need for a dimmer.

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

sammy004

So what do I need for a dimmer and how to I test that circuit without a breadboard?

Torben

That circuit has no earth ground and needs to be double insulated so there is no chance that a dangerous voltage can be exposed. It should never be connected to mains power while the insulated enclosure is open. After building it you should really have it checked over by a qualified electrician before plugging it in.

Bill, where do you see a log marking on the pot? I agree it's probably not up to the task (pot *or* switch) but it could be linear, no?

All in all, mains-powered circuits are not for the beginner. That thing could hurt you, kill you, or start a fire, and that picture just scares the willies out of me.


Torben

Bob Scott

I am surprised that nobody else noticed that those two wires are not connected to the ends of the pot as in the diagram. Instead they are connected to the switch. That's why the circuit won't work.

Other than that, use insulated wire and solder the joints on the pot, and beware of electrocuting yourself!

Bob

Torben

Holy cow, you're right. Never got past the initial reaction, I guess.


Torben

blueroomelectronics

The POT has a switch, generally used on a volume control for off / on. It could be a linear, but my moneys on log because of the switch (which isn't in the schematic though)

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

Torben

Gotcha. Just wondered because I've got both kinds in my box.


Torben

shaneshane1

you can use your breadboard! get some insulated wire! and get yourself a three pin pot, that thing you have created scares me

are you just wanting to use a pot to dim a LED?

just connect your pot in series with your LED and, of you go , done!!!
Use a 9V battery to be on the safe side and put a 350ohm resistor in series as well so you don't exceed 20mA(assuming the LED has a voltage drop of 2V)

__________________
If we were over 100 times the size we are now, then wouldn't what we already have be nanotechnology!!!

sammy004

Hey guys thanks for looking after me but I didn't ask for safety 101, I just wanted to know if that is the right pot or not, and are the CONNECTION on the right points not what they look like.

This is not for a LED and I'm not using any LED's.

Sorry to sound all uptight but with this project and my C++ Project I'm just going over the roof in frustration. So all I'm asking for is advice not a lesson on what electricity does!!!

Thank You

Torben

Hold on, chill out. Nobody's telepathic here. We saw something unsafe. Like seeing someone try to clean a gun with the breach closed or stoke a fire using a full gas can.

What the connections look like gives some indication of how they will behave when you turn it on. The notes aren't aesthetic, they're practical. Just twisting leads like that is something that I've found, through painful experience, makes circuits behave oddly.

Maybe you should explain what you're trying to do, not how. Could be there's a simpler (and safer) option. Nobody here wants to give advice and then read about it the next morning in the paper.


Torben

ericgibbs

hi,
This is how the pot is configured,

Please do NOT use a breadboard for developing mains powered circuits.

Also be aware that some pots are made with metallic shafts, I know they are supposed to electrically safe, but I would not use that type.

Does this explain it OK.?

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

Torben

Can you post a picture of the complete circuit?


Torben

ericgibbs

Morning Torben,
The OP did post the circuit in his 1st post, its a bog standard mains lamp dimmer.

Regards

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

Torben

Morning!

Sorry, I meant the constructed circuit on the breadboard.


Torben