| Product List |
|
 |
|
 |
|
Add:Yongli Road NO.6, Guodian, Yanguan Town, Haining City, Zhejiang 314412 China
Tel:+86-573-87297683 87179527
Fax:+86-573-87297683
Http://www.hn-yongli.com
Sales and Service:
ptc@hn-yongli.com
Technical Supports:
yl@hn-yongli.com |
|
|
 |
|
| |
 Products |
| Application in automotive |
Advantages:
| ·Self-regulating operation |
·No glowing parts |
| ·No excess temperature protection required |
·Various geometries possible |
| ·Available for all voltage ranges |
·Wide choice of surface temperatures (40 to 280 °C) |
| ·Prepared for clamping with plane-parallel contact surface |
·Long service life |
PTC Ceramic elements specification in automotive:
|
Dimension
|
Curie point
|
Rated voltage
|
Rated resistance
|
Surface temp
|
Broken-down voltage
|
Electrodes
|
Inrushing current
|
Operating temp.
|
|
(mm)
|
(℃)
|
(V)
|
(Ω)
|
(℃)
|
(v)
|
|
(A)
|
(℃)
|
|
35×5.5×1.6
|
120±10
|
24
|
11±40%
|
130±10
|
60
|
Al
|
--
|
-25-+125
|
|
35.4×14.5×1.4
|
130±8
|
24
|
1.84-3.45
|
155±8
|
60
|
Ag
|
--
|
-25-+125
|
|
35.4×14.5×1.4
|
240±10
|
24
|
2.0±35%
|
280±10
|
60
|
Ag
|
--
|
-25-+125
|
|
35.4×14.5×1.4
|
150±8
|
12
|
0.6±35%
|
170±10
|
50
|
Al
|
--
|
-25-+125
|
|
35.4×14.5×1.4
|
140±10
|
24
|
3-6
|
160±10
|
50
|
Ag
|
<10
|
-25-+125
|
|
35.4×6.2×1.4
|
142±8
|
13
|
1.36±30%
|
160±8
|
50
|
Al
|
--
|
-25-+125
|
|
35×10×2.0
|
255±10
|
18
|
3-8
|
300±5
|
50
|
Al
|
--
|
-25-+125
|
|
34.9×5.7×1.1
|
142±8
|
13
|
1.57±30%
|
160±8
|
50
|
Al
|
--
|
-25-+125
|
|
24×6.2×1.4
|
60±7.5
|
13.5
|
5.7±35%
|
85±7.5
|
50
|
Ag
|
<2.5
|
-25-+125
|
|
24×6.2×1.4
|
70±7.5
|
13.5
|
5.7±35%
|
95±7.5
|
50
|
Ag
|
<2.5
|
-25-+125
|
|
14.5×14.5×1.4
|
130±7.5
|
13.5
|
4.2±35%
|
105±7.5
|
40
|
Al
|
<4.8
|
-25-+125
|
|
Φ20.5×0.9
|
155
|
12
|
2.0±50%
|
180±5
|
50
|
Ag
|
--
|
-25-+125
|
Application in Automotive - Principle
There is a growing trend in automotive engineering toward electric heating of components and systems. Demands for greater economy, safety and convenience as well as environmental issues all play a part here. Self-regulating operation and high reliability make PTC a perfect heating element used in automotive.
A modern diesel vehicle contains up to 50 PTC heating elements. Key parameters of PTC thermistors are the rated resistance R25, i.e. resistance at a room temperature of 25 °C, and the reference temperature Tref or Tc, at which the resistance is twice the minimum value Rmin and at which the curve begins to rise steeply. The surface temperature Ts is the stable temperature at the surface of the PTC thermistor when rated voltage is applied . It is critical to thermal performance in the application and usually 10 to 20 degrees higher than the reference temperature. The higher the surface temperature, the more heat the thermistor can release to its colder environment.
In heating applications, PTC thermistors are operated in the low-resistance region of the steep section of their R/T characteristic for maximum thermal output. The positive characteristic means that electric power consumed matches thermal power dissipated. At an ambient temperature significantly lower than Tref, i.e. with good heat transfer, the thermistor has low resistance and consumes a relatively large amount of power. If the ambient temperature is significantly higher than TC or heat transfer is restricted, the resistance of the thermistor rises rapidly and power consumption is limited to a very low value. Followings are the introductions of some applications in automotive
.
Modern internal combustion engines of high energy economy cause less environmental pollution and reduce fuel costs. But their higher mechanical efficiency means that the engine generates too little heat to warm up the passenger compartment fast enough, especially at the beginning of a journey or in city driving. Here auxiliary electric heating modules based on PTC heating elements are used. They consist of laminar radiators fitted with PTC heating elements. Four to five thermistors per radiator are connected in parallel and held together in a spring-loaded frame. The plane spring contact ensures good current coupling and efficient thermal decoupling. The air flows through laminar radiators positioned between two layers of clamped PTC heating elements. Compact heaters with outputs up to 2 kW and higher can be implemented by stacking several layers of PTC heating elements and radiators. The flat heating modules are integrated into the air conditioning system behind the vehicle's standard heating unit. The various layers are usually switched on in stages to reduce inrush currents. As soon as the cooling water has warmed up sufficiently, the electric heating module is switched off again in stages.
Diesel fuels invariably contain long-chain hydrocarbons (paraffins) that can block the diesel filter at sub-zero temperatures. This problem can be avoided by preheating the fuel above the melting point of the paraffins, either with a flow heater or a kind of immersion heater. Another option is to heat the diesel filter directly. Selection of the right reference temperature will prevent the fuel from overheating.
Pressure fluctuations in the crankshaft housing can damage the engine. So if excessive pressure builds up, the gases within the housing flow back to the combustion chamber via a valve. If this ventilation system ices up, serious engine damage may occur. Heating tubes equipped with PTC heating elements are therefore used to prevent icing. The current trend is to use PTC thermistors with a very low reference temperature (about 0 °C) so that the element heats up only when required. Its resistance at room temperature is then so high that its power consumption is almost zero. PTC heating elements thus offer a simple and energy-saving solution to this problem.
Another application of PTC heating elements is to heat the washing nozzles for the windshield and rear window. The fine nozzles can easily ice up in winter because of their exposed position. A washing solution with a low freezing point cannot prevent this. So a single, disk-shaped PTC heating element is installed right next to the nozzle channel. The thermistor and wires are normally integrated into the nozzle so that it cannot be distinguished from a conventional nozzle when installed.
For all these applications, PTC heating elements are available in both standard and customer-specific versions. Their self-regulating properties and the broad range of types available open up many more applications. |
|
|
|
