help with a digital timer that turning a switch

Thread Starter

jack148

Joined Aug 25, 2015
17
hello everyone!
i'm new here, and i'm sorry about my english.
I'm a third year electric engineer student, and i want to do something:
i want to build a electronic device that connected mechanically to a switch of light(in my house),
with a display and buttons, and a micro-controller.
It need to be able to get a input of hours, and turn the switch after those hours (mechanically, without connecting it to the wires of the switch).

i want to start it with arduino, for prototyping...

how can i start? what components do i need?
thanks!
 

Thread Starter

jack148

Joined Aug 25, 2015
17
it will be with physical connection! it will be stick to the panel of the switch, and turn off/on it with a kind of stick that will move from a motor.
do i understandable? (sorry again about my english)
 

AnalogKid

Joined Aug 1, 2013
8,302
I think he's talking about a rod with a hole in the middle of it that drops down over a standard toggle light switch. Moving the rod back and forth with solenoids or a motorized actuator flips the toggle switch with no electrical contact with the house AC.

ak
 

MaxHeadRoom

Joined Jul 18, 2013
19,983
Something like a relay gives you galvanic isolation, without going to fancy mechanics?
If manual control is no longer used, use the relay to switch the circuit.
Max.
 

mcgyvr

Joined Oct 15, 2009
5,394
Do you want to use servos or solenoids or pneumatic cylinders to control the motion?
How accurate do you need the time to be? Arduino can do timing without anything else but its not very accurate.
If you need accuracy then you would need an RTC (real time clock) circuit.

There are TONS of tutorials all over on the internet to do what you want..
Have you tried searching already?

Its simply a matter of some timing functions, display/menu functions and servo control.

A simple 2x16 LCD, a button or two, a servo motor, a few 10k resistors, and an arduino is all you need to get started..

As a 3rd year Engineering student you should be able to learn/get started on your own by now IMO.


If you want to mechanically control the switch thats just fine.. Its just not the way most would do it (relay/SSR or similar).. But its your project and is safer than having to interact with hazardous voltages.
 

Alec_t

Joined Sep 17, 2013
10,901
A hobby servo would be my choice as the mechanical actuator, assuming the switch has a conventional rocker or toggle.
 

Thread Starter

jack148

Joined Aug 25, 2015
17
Thank's!!
it's strange that i'm 3rd student and I don't know nothing abut that!
i know only mathematics and physics....

about searching internet's tutorials - i tried but without success...
where can i search?

thank you everyone!
 

Thread Starter

jack148

Joined Aug 25, 2015
17
thanks a lot.

In the final version i want it without the arduino.
is it ok for start with arduino and if it works change it to a simpler micro-controller?
 

mcgyvr

Joined Oct 15, 2009
5,394
thanks a lot.

In the final version i want it without the arduino.
is it ok for start with arduino and if it works change it to a simpler micro-controller?
Sure..
But realize you may/will have to potentially rewrite the code from scratch/create new hardware,etc...

Not sure why you wouldn't want to just keep the Arduino in the "final" version.. Maybe use an Arduino nano/pro mini if size is an issue.. This isn't a product you could sell or anything so I'm not sure why you would want to swap out the main device to make a "final" version..
 

Thread Starter

jack148

Joined Aug 25, 2015
17
thanks.
Just a general question:
i want to use power supply for arduino, from wall outlet.
do i need to buy somthing like that (i found in ebay at 1$), or i need to try building it? (as a newbe starter....)
 
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