Custom PTC Overheat Protection Sensor Manufacturer | Wholesale OEM Supplier
As a custom temperature sensor manufacturer with over 5 years of focused experience in temperature sensing technology, Evergreen operates a 13,000 m² production facility certified to ISO 9001:2015 and ISO 14001:2015, and supplies wholesale OEM volumes of PTC overheat protection sensors to Fortune 500 partners across the United States, Europe, and beyond.
We design and produce PTC sensors for overheat protection, temperature switching, and self-regulating heating, with engineering support for custom switching temperature and form factor — backed by a quality system that spans raw material inspection through final performance testing.
| Core Principle | Positive Temperature Coefficient: Resistance increases sharply as temperature rises. |
| Product Overview | A type of sensor characterized by a sharp change in resistance in response to temperature variations. It is primarily used for overheat protection, temperature switching, and self-regulating heating. |
| Typical Applications | Overheat protection in motors (e.g., fans, water pumps) · Overcharge/overheat protection in batteries · PTC heating elements (e.g., automotive seat heaters) · Overcurrent protection in circuits (as self-resetting fuses) |
| Recommended Use | Ideal for applications requiring temperature switching, limit protection, or heating, such as: Safety protection in industrial equipment · Safety circuits in appliances · Thermostatic heaters |
| Key Advantages | Excellent switching characteristics · High reliability and maintenance-free operation · Integrates both sensing and switching functions |
PTC Temperature Sensor Operating Characteristics
Unlike NTC and RTD sensors, which are used for continuous temperature measurement, PTC switching thermistors are designed around a defined trip point (Curie temperature) where resistance increases abruptly by several orders of magnitude. This behavior is what makes PTC sensors effective as self-resetting thermal protection devices rather than precision measurement components.
| Parameter | Typical Behavior | Notes |
|---|
| Switching / Trip Temperature | Defined per application (e.g. motor winding class, battery chemistry limit) | Custom switching temperature available — confirm with our engineering team for your protection threshold |
| Resistance Behavior | Sharp, non-linear resistance increase beyond trip temperature | Not intended for linear/continuous measurement — see NTC or RTD sensors for that use case |
| Reset Behavior | Self-resetting once temperature drops back below trip point | Functions similarly to a resettable fuse |
| Typical Use Case | Overheat protection, current limiting, self-regulating heating | Not recommended where precise temperature value (not just a threshold) needs to be measured |
| Waterproof / Probe Protection | Custom probe sealing available |
|
| Package / Form Factor | Disc, radial leaded, probe-encapsulated, or PCB-mount | Customizable per application and installation method |
* For exact switching temperature and electrical specifications of a specific model, please request a datasheet — PTC sensors are typically specified to your application's protection threshold rather than sold as a single fixed catalog spec.
PTC vs. NTC vs. RTD: Which Temperature Sensor Is Right for You?
PTC sensors are chosen specifically for protection and switching applications — not as a substitute for continuous temperature measurement. Here's a quick comparison to help guide your sourcing decision:
| Type | Resistance Behavior | Typical Accuracy | Best For |
|---|
| PTC Thermistor | Resistance increases sharply past a threshold (switching behavior) | Switch-type response rather than linear measurement | Overcurrent/overtemperature protection and self-regulating heating, rather than precision measurement |
| NTC Thermistor | Resistance decreases as temperature rises | High sensitivity, ±0.5%–3% | Fast, low-cost, high-sensitivity measurement in a moderate temperature range (consumer electronics, appliances, batteries) |
| RTD (Pt100/Pt1000) | Resistance increases linearly and predictably with temperature | Very high long-term stability, typically ±0.1°C–0.5°C (Class A/B per IEC 60751) | Wide temperature range, long-term stability, and industrial-grade repeatability |
Need help deciding? See our NTC Temperature Sensor and Pt RTD Sensor pages, or contact our engineering team for a sensor selection recommendation based on your application.
OEM & Custom PTC Sensor Manufacturing
As a professional custom PTC sensor factory, we provide OEM and application-specific solutions, including:
Custom switching/trip temperature to match your protection threshold
Resistance characteristics and response tuning
Custom package type and form factor (disc, radial leaded, probe, PCB-mount)
Custom cable length and connector configurations
Custom waterproof probe sealing for harsh environments
From sample development to stable wholesale-volume mass production, we support long-term OEM cooperation with consistent quality control.
MOQ, Sample Lead Time & Wholesale Pricing
We support both small-batch sampling for product development and wholesale-volume orders for production-stage sourcing.
Minimum Order Quantity (MOQ):
MOQ varies by customization level — standard catalog items generally have lower MOQs than fully custom switching-temperature designs. Contact us with your target volume for a tailored quote.
Sample Lead Time:
Sample lead time depends on customization scope. Confirm exact timing with our team for your specific requirement.
Wholesale Pricing: Volume-based pricing available — contact our team with your target switching temperature and volume for a tailored quote.
Frequently Asked Questions
Q: What's the difference between PTC and NTC sensors?
A: NTC sensors are used for precise, continuous temperature measurement, while PTC thermistors are designed for overheat protection and switching applications — resistance jumps sharply once a threshold temperature is reached, rather than changing gradually. See the comparison table above for details.
Q: Can the switching temperature be customized?
A: Yes. The trip point can be tailored to your specific protection requirement — for example, motor winding insulation class or battery cell safety threshold.
Q: Can a PTC sensor be used for precise temperature measurement?
A: PTC sensors are designed for threshold-based protection and switching, not continuous precision measurement. If your application needs a precise temperature value rather than a pass/fail threshold, our NTC or Pt RTD sensors are typically a better fit.
Q: Do you offer waterproof PTC probes?
A: Custom probe sealing is available. Please share your application's environmental exposure level so our team can confirm the appropriate protection rating for your design.
Q: What is your MOQ for wholesale orders?
A: MOQ depends on whether you're ordering a standard catalog configuration or a fully custom switching-temperature design. Contact our team with your target volume and specification for an accurate quote.
Q: Are your PTC sensors certified?
A: Our manufacturing facility is certified to ISO 9001:2015 (Quality Management) and ISO 14001:2015 (Environmental Management).
Get a Custom PTC Sensor Quote
Whether you need a standard PTC overheat protection sensor or a fully custom switching-temperature design, our engineering team is ready to support your project — from sample development to wholesale-volume production.
Request a Quote | Explore Custom Solutions
