Need advice/instruction on a simple electronics question....

[inequitude]

Hi guys- I have a question which I hope one of you in this forum can help me with.

I'm got my artistic hat on and am playing around with a sheet of thermochromic ink which I want to lay on the front of a canvas.

Behind the thermochromic ink I want to lay a pattern using some heat conducting wire which will attach to a 9v battery behind the canvas.

The idea is that when the battery is connected, the wire heats and activates the thermochromic ink, thus revealing in all it's splendor the pattern I have made with the wire behind it.

The tricky part is that I want this heat/battery to conduct through the wire as a pulse, ideally approx every 60 seconds for several seconds.

Is it possible? and what electronics do I need to get to make this happen? If someone could explain to me in layman's a) what i need to purchase, and b) the process of assembly, I would be most grateful.

...ideally if I could buy this little pulse/delay mechanism thing already made up from somewhere it would be fantastic, as I dont have the suspected requisite equipment.

Please advise

Cheers,
Chris.

 

[cameo_2007]

I think you probably didnt get a response for this is because your application is not clear. It looks like its kind of simple but you need to explain this in a better understandable way.

 

[jiripolivka]

Re: Need advice/instruction on a simple electronics question

Dear Chris:

Your description sounds interesting but to make your idea work you will have to run some experiments before you can ask technical questions.
1. Only you know some properties of your "thermal ink". To be able to heat it up, you must learn what temperature it needs to do so. Some inks do change colour by heating but if you overheat it, it can change its colour again.
2. You should use a piece of fabric with the ink line or contour; then you can run a thin resistive wire through the fabric so it can heat up the ink. Using a DC power supply with a variable output voltage, and an ammeter, you should find by trial how much current your wire needs to activate the ink.
3. Knowing the current, you will have to find out how long the wire must be for a certain ink pattern. From this you should determine a necessary voltage of a battery to connect to your invention. If the voltage looks too high for a wire length, you can divide the wire into two or more equally long sections. Then the current must be a multiple of wire loops.
4. By such trials you will learn how to use the resistive wire, and using Ohm's Law and Kirchhoff Law you can design the system as well as its power supply (battery).

 

[srizbf]

Re: Need advice/instruction on a simple electronics question

'jiripolivka' has already given you the way to go.

i will add some more.

you must know the temperature to which the thermoink is to be heated.

based on that you must selct suitable heating wire.

if there are many such wires (or) one wire going thro all over canvas , you must specify.

based on the power required for heating the canvas , then the circuit can be suggested.