PTC Heaters for 12 Volt Circuits
Positive temperature coefficient heaters (PTC) are ideal for small places requiring 12 Volt AC/DC power. These micro heaters work at a constant temperature, not requiring additional temperature controls, minimizing circuit components.
12 Volt PTC heaters come in surface, air, or fan heater configurations. The small PTC ceramic heating element is embedded in the heat conductive case and prewired for connections to the 12-volt circuit.
How does the PTC heater work?
The ceramic heating element inside the heater is made by compressing ceramic materials blended for specific characteristics and temperature. The positive temperature coefficient characteristic means that as the device heats to a constant temperature, the resistance to current flow increases logarithmically.
This increase in resistance decreases the current and the heat generated from exceeding the set temperature.
When initially turned on, the resistance is low, and the current that heats the element starts at maximum. This is ideal in cold weather when you want a minimum warm-up time for the heater. However, if the ambient temperature is higher, the device automatically adjusts proportionally to the temperature and does not heat as quickly.
What is the temperature range of PTC heating?
PTC heating elements are designed for specific temperatures marked on each device. 12-volt devices can be rated from 104° F - 284° F maximum temperature. Be sure to check the tolerance of each appliance which could be + or - 18° F.
When selecting a device, consider that the max temperature is the ceramic element itself and not the surface of the heat transfer enclosure or surrounding air.
Check with the manufacturer for heat transfer characteristics and other design considerations.
Are there different types of 12 Volt PTC heaters?
There are several types of PTC heat transfer devices, but 12-volt devices are usually surface or fan configurations.
Surface mounted heating configuration applies direct heat to a surface rather than air by attaching the aluminum housing directly to a surface. For example, suppose it is a surface of a container; that surface then transfers the heat to the contents.
How are PTC heaters connected to a 12-volt circuit?
Each ceramic disk is connected to wires insulated from the heat exchanger and long enough to connect to an external terminal block. The wires have thermal insulation to prevent damage from the heat produced by the device.
Some heaters come with terminations, while others will require solder or crimp connections. The wires used for termination are rated for the potential inrush current and high temperature.
The PTC heating elements are unique in that they can operate off of AC or DC circuits. Each circuit does need an off/on switch to remove power from the heaters, but no other control devices are required.
Does the PTC device burn oxygen?
The positive temperature coefficient devices are solid-state, which creates no open flame, nor are their resistance wires to burn oxygen. This makes the PTC heaters safe for oxygen-enriched environments like medical applications or other hazardous vapors.
How big are the 12-volt PTC heaters?
The length of a DBK Cirrus 25 fan heater is 2 to 3 inches in length with a 1-inch cross-section. They weigh between 2 and 3 oz.
The DBK HP05 series of PTC surface heaters has a mounting face of 1.58 X 1.38 inches, and the 06 series is 2.95 X 1.38 inches. The depth is 0.327 inches. Each series has prewired 4-inch leads.
Need help deciding on the right heater for your application?
Call DBK USA directly at 1-864-607-9047 and speak with an engineer specializing in Thermal Management devices. They can answer any questions and provide information on custom designs or large quantity orders