Electronics Forum

by **sawadeejar** » Tue Apr 05, 2011 3:08 pm

Dear all,

Anyone has an idea how to build heat generating circuit with 9v battery?
This schematic found at [url]http://www.kobakant.at/DIY/?p=2909[/url] using 24v supply. I wonder how to modify it to work with 9v instead of 24v power supply.

Thanks.

by **pebe** » Wed Apr 06, 2011 11:18 am

What sort of 9V battery?
How much heat to you want to get from it?
Can you not use a switch?

by **sawadeejar** » Thu Apr 07, 2011 9:07 am

[quote="pebe"]What sort of 9V battery? How much heat to you want to get from it?
[/quote]
My first plan was to use PP3 V9 battery but I've realised that it's not powerful enough to create required heat 15 - 40 c degree. Note: the heating element is conductive thread (12Î©/foot)

The circuit will be embedded in clothing so the power source should be lightweight and portable. What type and voltage of battery would you recommend?

[quote="pebe"]
Can you not use a switch?[/quote]
Can you explain more on this option please?

by **pebe** » Thu Apr 07, 2011 6:22 pm

The battery with the largest output for its weight is probably the Li-Ion battery as used in mobile phones, etc. I don't know what voltage or capacity you need because I know nothing about this heating thread.

Re. the switch option, I noticed the circuit you were considering went to great lengths to switch on power to the thread stuff, and wondered why you did not use a simple on/off switch.

by **sawadeejar** » Thu Apr 07, 2011 7:32 pm

[quote="pebe"]Re. the switch option, I noticed the circuit you were considering went to great lengths to switch on power to the thread stuff, and wondered why you did not use a simple on/off switch.[/quote]

I've planed to use switches as seen in the attached picture. Each switch is waiting for the controller to trigger so 1 heat circuit can be used to supply heat to multiple threads at the same time and different time.

Is this a good plan?

by **pebe** » Thu Apr 07, 2011 7:47 pm

You have four manual switches. How do the outputs from D1-D4 do any switching?

by **sawadeejar** » Thu Apr 07, 2011 8:07 pm

D1-4 outputs will be controlled as high or low. High --> turn ON, Low --> turn OFF.

by **pebe** » Fri Apr 08, 2011 5:39 am

Your outputs from D1 to D4, going to the output of the heat controller and feeding all of the manual switches connected together makes no sense at all.

by **sawadeejar** » Fri Apr 08, 2011 6:29 am

You are right.
Is there a way to control each heating element separately?

I only can think of using 4 heat circuits connented to the microcontroller.