The spec is a ptc resistor of 5 -50 W. Designed to reach 220CSupply volts 12.So presumably resistance varies from ( 12^2/ 50) =>2.88 ohms at say 20C to 28.8 ohms at 220CYou won't drive that with a little 9V block battery with any technology I know.Allan
Polymer PTC heating elementsA flexible PTC heater made of conductive rubberResistive heaters can be made of conducting PTC rubber materials where the resistivity increases exponentially with increasing temperature. Such a heater will produce high power when it is cold, and rapidly heat up itself to a constant temperature. Due to the exponentially increasing resistivity, the heater can never heat itself to warmer than this temperature. Above this temperature, the rubber acts as an electrical insulator. The temperature can be chosen during the production of the rubber. Typical temperatures are between 0 and 80 °C (32 and 176 °F).It is a point-wise self-regulating heater and self-limiting heater.[clarification needed] Self-regulating means that every point of the heater independently keeps a constant temperature without the need of regulating electronics. Self-limiting means that the heater can never exceed a certain temperature in any point and requires no overheat protection.
Hi,What is the application?What are you heating?What is the temperature you are trying to attain?Do you aim to have temperature feedback to control temperature?Are you aware that this not a "normal" resistive type heater?Are you aware that its resistance changes over a relatively large range with temperature, unlike most heater elements?Do you know what PTC means, (Positive Temperature Co-efficient)?Thanks ... Tom...
If you are ( as I previously guessed and you half confirmed ) trying to make better electrically heated gloves for motorcycle use there are some sums to do.Firstly the power required. This depends on the temperature you wish to maintain the hands at , the external air temperature, the air speed , and the thermal insulation properties of the glove materialsSecondly the difference in power per unit area required in various areas of the glove - obviously the extremities such as the fingertips require a higher rating.I'm sure the existing manufacturers have made measurements of all the unknowns above to come up with a practical product.Materials such as the PTC conductive rubber suggested by Tom may be useful.But if my guesses are correct, why would you want independent battery power? - a modern motorcycle has a powerful alternator and wouldn't even blink at this small extra load.Even if perfectly controlled, your 3 x Li 2AH cells would only power such a pair of gloves at 10 watts each for about an hour . I've done much longer journeys than that in wintertime on a motorcycle.Allan
If you told us the full details, we wouldn't have to keep second guessing. Just the fingertips is very verydifferent from a full heated glove, about 10 times less power is needed for one thing.I have some questions:Heat up to 40C from what ambient temperature?What response time to reach target temperature? Or is that a steady-state temperature to bemaintained.Indoors or outdoors or both?
the temperature is relative to the finger temperature