Portable Water Warmer

[screamer]

I have to make a portable water warmer for a college project. I have a warming strap that I have taken out from a MotherCare bottle warmer which use car ignition as a power source. It has a rating of 2A 12V. So I my idea is to use a battery to supply the strip and to use a 555 timer to make it on for a certain time and off for a certain time. So that I can prevent the warmer from getting too hot and also preventing it from cooling down too much. Also preserving the battery for longer. I intend to use a manual push switch to completely off the supply. So I would like to know if this is possible? Also some guidance and some schematics i can refer. I am fairly new to this and I have just 2 months to complete it. Hope to get some help. Thanks in advance.

[berkeman]

I have to make a portable water warmer for a college project. I have a warming strap that I have taken out from a MotherCare bottle warmer which use car ignition as a power source. It has a rating of 2A 12V. So I my idea is to use a battery to supply the strip and to use a 555 timer to make it on for a certain time and off for a certain time. So that I can prevent the warmer from getting too hot and also preventing it from cooling down too much. Also preserving the battery for longer. I intend to use a manual push switch to completely off the supply. So I would like to know if this is possible? Also some guidance and some schematics i can refer. I am fairly new to this and I have just 2 months to complete it. Hope to get some help. Thanks in advance.

Welcome to the PF.

We do not do your project work for you (see the Rules link at the top of the page). Your idea seems fine, and you should look on the Internet for example 555 schematics and tutorials. Try googling 555 tutorial to get you started.

And for your 12V battery, you can either use a small version of a car battery, or you can series connect some D-size batteries to add up to about 12V.

EDIT -- BTW, you won't be able to drive that kind of current with the 555 directly. You will want to use a transistor to do that. Look for information on the "common emitter" configuration of NPN transistor.

[Windadct]

Also - the better solution will use a thermistor and provide basic closed loop control. - And agreed - you will want something to "drive" the output power based on the signal from the 555.

[dlgoff]

Food for thought:

http://en.wikipedia.org/wiki/PID_controller