Prevent Inrush Current with PTC and NTC Thermistors PTC and NTC thermistors can provide inrush current protection in various equipment, machinery, and systems. Inrush current affects a wide range of products, from transformers to motors, and electronics from power supplies to inverters. Inrush current becomes further complicated by systems that switch on and off quickly, such as welding equipment and HVAC systems. This post will give you a brief overview of … Continue Reading
Thermistors vs. Thermocouples Temperature sensors are important for everyday life, from working in industrial plants to preventing fires. Thermistors and thermocouples are two such temperature sensors. A thermistor is a thermally sensitive resistor that exhibits a continuous, small, incremental change in resistance correlated to temperature variations. Thermocouples reflect proportional changes in temperature through the varying voltage created between two dissimilar metals electrically bonded together. Both are good options for temperature … Continue Reading
Thermistor temperature sensors have broad applicability NTC Thermistors are non-linear resistors that alter their resistance with temperature. Resistance on an NTC probe will decrease predictably as the temperature increases allowing for extremely accurate temperature measurements. These temperature sensors have applications within environmental science, prevention, medical, building automation, aerospace, automotive, life safety, and others. One industry not immediately thought of for thermistor temperature sensors is the bowling industry. A … Continue Reading
NTC Thermistor Probes Have Endless Applications NTC thermistor probes measure liquid levels and temperature in industries that extend from automotive electronics to medical technology to green energy. Their applications are endless, and their purpose ensures the operability of the applications they serve. A thermistor probe, can also be as simple as an NTC thermistor chip, encapsulated with epoxy or glass. Or, it can be potted in a metal or plastic housing … Continue Reading
Temperature sensors range in accuracy and responsiveness Some applications, such as equipment used to create life-saving medications, require temperature sensors to be responsive and accurate for critical quality control; however, some applications, like the thermometer in your car, don’t require as accurate or responsive sensors. The four most common types of temperature sensors, ranging in responsiveness and accuracy from high to low are: Negative Temperature Coefficient (NTC) Thermistors Resistance Temperature … Continue Reading
Pre-Charge Circuits Prevent Damage to Inverters Severe damage can occur to inverters when the inrush current is too great for the inverter. Pre-charge circuits protect the inverters by controlling the initial power surge. PTC thermistors can help a pre-charge circuit protect the inverter. Inrush current occurs when the maximum instantaneous input current flows through a system when the electrical power is switched on. In power tools, such as power drives, … Continue Reading
Choosing An Inrush Current Limiter To Preserve Your DC Motor So, what does an Inrush Current Limiter have to do with DC motor inrush? More than you may think. DC motor inrush is the maximum, instantaneous input current drawn by the DC motor when first turned on and it is important to know how to limit the inrush current to prevent possible damage to the motor. A DC motor converts … Continue Reading
Inrush Current Limiters protect electrical equipment from overheating at switch-on due to the surge of input voltage from the power source. Selecting the right Inrush Current Limiter is important. For example, switching power supplies, DC motors, and lighting ballasts can develop extremely high peak inrush current at turn-on unless you implement inrush current protection. Because inrush current equals the maximum instantaneous surge of incoming current from a power source, it … Continue Reading
Inrush current can cause considerable damage to electrical applications. It is important to control this starting current with the right inrush current limiter. In this article we look at what can happen when you choose the wrong circuit protection device. Then we demonstrate how to choose the right circuit protection device. Finally, we show the dramatic difference between using an inrush resistor and not using one in a vacuum motor. … Continue Reading
Written By Joe Conti NTC thermistors are a great way to control the power functions of a residential furnace system. These thermistors can sense the air temperature in the furnace heating chamber and turn the power on and off. Replacing the power control of the furnace with a temperature sensor is easy to do. This article will walk you through how to do this starting with an Arduino microcontroller and … Continue Reading
Ryan Martin, Bora Stitch LLC Ryan Martin, owner of Bora Stitch LLC, a commercial embroidery business based in West Chester, Pa., sought out Ametherm for an inrush current limiter solution for a 2001 Tajima embroidery machine being used to sew hats for the Boy Scouts of America. Because of Ametherm’s policy to always have a live person available to answer calls and questions, Ryan was able to speak with an … Continue Reading
One common way to protect NTC thermistors from damage that might impair performance is to encase them or house them in epoxy. The chemical characteristics used to protect NTC thermistors are found in industrial grade epoxy with a high dielectric strength and thermal conductivity. An epoxy coated NTC thermistor temperature sensor appears as a tear-drop-shaped bead with two radial wire leads. Very often these types of NTC thermistor temperature sensors … Continue Reading
There is a lot of information available about inrush current limiters and their different applications, capabilities, limitations, and other particular details. But very infrequently is the most basic question asked, what is an inrush current limiter and why is it used? To access, appreciate, and apply the benefits and solutions that these components provide, it is important to first be able to understand, acknowledge, and answer the question of what … Continue Reading
Regulating Inrush Current at Powerup At powerup, DC/DC converters draw a large amount of electrical current. This inrush current can be fatal to both the converter and the load if not controlled at the beginning. To achieve a soft start, when the electrical current rises gradually to its specified level, the use of an NTC Thermistor Inrush Current Limiter can be vital. DC/DC Converters DC/DC converters transform a source of … Continue Reading
NTC Thermistor Inrush Current Limiters are used to reduce the inrush current that occurs when an electrical device is switched on. High inrush current is the result of the maximum instantaneous input current drawn by electrical equipment during the initial power up. As technology continues to advance, most systems today run efficiently and maintain a low impedance, which in turn contributes to a high inrush current. Cool-Down Time After Power … Continue Reading
Interchangeable Device Eliminates Conduction Between Leads for the Highest Temperature Sensing Accuracy Ametherm today (April 9 2018) announced that the company has extended the capabilities of its ACCU-Curve series of interchangeable NTC thermistors with the ACL-011. This new device features insulated tinned-copper leads, ensuring the most accurate temperature sensing with no unintended conduction between leads. Ametherm’s ACL-011 delivers long-term stability and reliability for high-accuracy temperature sensing, control, and compensation in … Continue Reading
The sky is blue. The outdoor temperature is rising. The time to get that pool back up and running is now! Whether you run a pool business or are a pool owner, you know how important it is to have your pool chlorinator running smoothly, all season long. But what do you do when your pool chlorinator stops working? Buying a new one might be the first thing that comes … Continue Reading
Reducing Inrush Current to Capacitors Calculating the amount of current flowing to a capacitor, then protecting your load from this initial flow of current is important for any electronic device. The ability to reduce this inrush, caused at powerup, can typically be accomplished by the use of an NTC (negative temperature coefficient) thermistor inrush current limiter. Cause of the Inrush Current Filter capacitors are devices designed to reduce the effect … Continue Reading
From the creation of the first inrush current limiter series, back in 1994, Ametherm knew that having logic behind the series naming convention would be important. Not only for organizational means but also to easily identify the components of the inrush current limiters and NTC thermistor temperature sensors. Both product lines, the inrush current limiters and NTC thermistor temperature sensors, have stringent guidelines created to get the most accurate description … Continue Reading
Ametherm announced its product lineup for the Applied Power Electronics Conference and Exposition (APEC) 2018. The company will be showcasing a wide range of its leading NTC and PTC inrush current limiters for reliable circuit protection and NTC thermistor sensors for high-accuracy temperature compensation and measurement. Featured inrush current limiters at APEC 2018 will include the company’s MS35 series of rugged NTC thermistors. Perfect for applications such as wind turbines, … Continue Reading
NTC thermistor temperature sensors are a key component in Li-Ion battery charging and safety. They provide critical temperature data required to keep the Li-Ion battery in the optimum condition during the charging cycle. Careful management of temperature during charging prolongs battery life and avoids hazards inherent to Li-Ion batteries. Li-Ion Batteries Power Green Energy Due to their light weight and high energy density, Li-Ion batteries are used exclusively in consumer electronics. Li-Ion batteries are … Continue Reading
Inrush current protection for LED lighting retrofits can be key to a successful lighting upgrade. Retrofit of LED lighting into an existing electrical system relies on the equipment already in place. This can be problematical due to the high inrush current created by the LED drivers. Falling LED prices and immediate energy savings are propelling the upgrade of older lighting modalities to new LED lighting for commercial and institutional users. For facilities management, benefits of a … Continue Reading
Large power users require mitigation of inrush currents as part of overall energy management strategy. Industrial automation with motor drives and logic controllers, high voltage power supplies feeding industrial robotics and solar panel arrays with large capacity power inverters all require inrush current limiting. Overview Inrush current is the momentary surge of current created when power is turned on to motors, transformers, power supplies and heating elements. These … Continue Reading
We’ve made a discovery and wanted to share it with you; introducing the Arduino Uno. If you’re an electronics geek who’s been wanting to learn more about the vast community of “Hardware Hackers” out there, read on! We discovered that you could hack together some awesome stuff with an Arduino Uno and other electrical components such as thermistor temperature sensors. And when you combine the Arduino and thermistors the possibilities are endless. We … Continue Reading
NTC Thermistors For Cooling Applications Thermistors are expanding in their applications every day. This year, EVGA, an American computer hardware company, redesigned its leading cooler to better monitor and cool power components in addition to the Graphics Processing Unit (GPU) component. In order to accomplish this, EVGA introduced Negative Temperature Coefficient (NTC) thermistors to its Printed Circuit Board (PCB). These NTC thermistors express large decreases in resistance in response to … Continue Reading
We couldn’t keep it a secret any longer. Finally, a UL approved circuit protection thermistor (Inrush Current Limiter) that’s just 12.3mm in diameter but packs an energy rating of 40 (J), yes; we said 40 (J) plus a maximum continuous current rating of 6.0A. Meet our upgraded UL certified SL12 10006 for limiting inrush current. We think this device is a game changer! Up until now if an application required … Continue Reading
Limiting Heat Lamp Inrush Current Incandescent heat lamps create a large inrush current when first powered on. Limiting heat lamp inrush current prevents relay damage and extends lamp life. Heat lamps can be used to warm enclosed areas such as livestock pens and chicken coops. Banks of incandescent heat lamps are mounted overhead. As the number of heat lamps increases, limiting heat lamp inrush current becomes more important. Over current can damage relay contacts in … Continue Reading
These 5 thermistor sensor considerations will make selecting the right NTC thermistor easy Selecting a thermistor temperature sensor can be confusing, and you have a lot of options to choose from. You don’t want to risk equipment failure or circuit breaker short-outs. So, how do you make the right selection without sacrificing performance and giving up quality? See what the 5 thermistor sensor considerations are all about to find out! … Continue Reading
Limit AC Motor Inrush Current In Air Conditioner Application AC motors used in air conditioning equipment draw large inrush current at power-on. A recent customer of ours had a 115VAC air conditioner installed in their travel trailer for park use. This 15,000-BTU unit required 16 amps for simultaneous compressor and blower motor operation. The trailer was also equipped with a load-shedding power distribution panel to protect its wiring harness from overload. If more … Continue Reading
Thermistor Sensor Blog Archive The thermistor sensor blog archive contains articles relating to temperature measurement, compensation, and control.
Inrush Current Blog Archive The inrush current blog archive contains articles relating to inrush current, it’s causes, cures, and prevention. Inrush Current Limiting
Application Overview Ametherm’s DG series glass-encapsulated thermistors provide long-term stability and reliability for high-accuracy temperature sensing in automotive and industrial applications. Hermetically sealed, the thermistors eliminate errors in resistance readings due to moisture penetration, while offering high operating temperatures and a compact size. DG Series Application Benefits Provides faster, more accurate, and less expensive alternatives to thermocouples and RTD probes Free from limitations due to solder temperature, which enables them … Continue Reading
The Relationship between Thermal Time Constant and Temperature Sensors In this article, we’ll break down the relationship between the thermal time constant and NTC thermistors. We’ll also cover the importance of selecting the right thermistor with characteristics that will produce the correct thermal time constant for your application. Further down in this article, we demonstrate one way to measure thermal time constant; running two tests, then present the results. What is Thermal … Continue Reading
An Inrush Current Limiter (ICL) can protect electrical equipment from overheating when switched on because of inrush current. And, because inrush current equals the maximum instantaneous surge of incoming current from a power source, it can be as much as 2 to 3 times the steady state current of the attached device. Inrush Current Calculators are the best way to measure the resistance versus temperature curve to get the right Inrush Current Limiter. … Continue Reading
Thermistors serve a crucial role in temperature detection. For example, thermistor temperature detection can be used in fire alarms to detect fires based on a sudden change in temperature. Unlike photoelectric detectors or ionization alarms, thermistors only require heat to activate. Thermistors are temperature-sensing elements made of semiconductor material that displays large changes in resistance in proportion to small changes in temperature. Photoelectric and Ionization Fire Alarms The photoelectric detector requires heavy smoke … Continue Reading
Application Overview Ametherm’s MS35 series inrush current limiting thermistors play a key role in alternative energy applications by avoiding current spikes in the power generated by wind turbines, solar panels, and other sources as it’s fed into batteries, inverters, and other energy storage components. The MS35 devices are also used to regulate the release of battery energy in electric vehicles and in pre-charge circuits for many different types of battery … Continue Reading
What You Need to Know About Toroidal Transformer Inrush Current Toroidal Transformer Inrush Current can cause some serious damage if not appropriately managed. Inrush current can cause circuit breakers to trip and fuses to blow. Additionally, it can cause a complete failure of the transformer itself. And if that weren’t enough to give you a headache, excessive inrush current can also limit the total number of devices which can be … Continue Reading
What Do RT1, RT2, T1, and T2 Have In Common? They are the main components of Thermistor Beta Calculations as it relates to temperature measurement, compensation, and control. And if you are an engineer in an industry such as automotive or HVAC where things like coolant and air intake temperatures are crucial to the safety and performance of a vehicle or unit, chances are you will deal with beta calculations … Continue Reading
Award-Winning Hyperloop Pod Uses NTC Thermistors A team of engineers use NTC thermistors in their design for a high-speed transportation pod. The thermistors accurately sense temperatures and create a map of the application’s heat. Teslarati recently conducted an interview with members of the Badgerloop team, 3rd-place winners of SpaceX’s Hyperloop Pod design competition in January. The Hyperloop is Tesla CEO Elon Musk’s “fifth mode” of transportation where passengers in a … Continue Reading
OBJECTIVE Ametherm inrush current limiters are used in many applications today that require suppression of surge current when power is first applied to the system. One of the popular applications of Ametherm inrush current limiters is in power factor correction circuits. This article provides a solution for finding the correct power factor correction (PFC) circuit for an inductive load. This solution is suitable for applications that include ballasts, LED drivers, … Continue Reading
By Balaji Santhanam, Hubble Power Systems Mehdi Samii, Ametherm Inc. Originally Published in Power System Design Magazine As electronic systems continue to become more compact, temperature plays an increasingly important role in system reliability and power efficiency. Many engineers are already familiar with how temperature can affect reliability; if a system becomes too hot, device operation can become unpredictable. Using a simple temperature sensor like a thermistor, the host processor can monitor … Continue Reading
Recently, the SFGate released an article about how thermistors are used to measure temperature change in Lake Tahoe. The article states that over the past 40 years, global warming has caused the temperature of lakes to rise, affecting the natural habitat for fish species and algae blooms. Scientists at the Tahoe Environmental Research Center carefully monitor the lake’s temperature using thermistors carried by large ocean buoys. Signals from the buoys transmit data via satellite to scientists at NASA’s Jet Propulsion Laboratory in … Continue Reading
What’s an ACCU-CURVE™ Thermistor? ACCU-CURVE™ thermistors are used for high-accuracy temperature sensing, control, and compensation in medical, industrial, and automotive applications. They also deliver long-term stability and reliability, while offering interchangeability over a broad temperature range. This eliminates the need to individually calibrate or provide circuit compensation for part variability. Accurate temperature measurement to ±0.2°C is available over the 0°C to 70°C temperature range. Standard ohmic values at 25°C range from 2,252 to 100,000 ohms. ACCU-CURVE™ Thermistor vs. … Continue Reading
To use a temperature sensor in a control or compensation circuit, the detection circuit must provide an output in a usable format. For analog circuits, the output is usually a resistance. For digital control and compensation, the measurement needs to be converted to a digital format for processing by an MCU. This is commonly achieved by reading the measurement as a voltage using an analog to digital converter (ADC). Semiconductor-based sensors … Continue Reading
The time has come for Ametherm to go digital! While pen and paper remain true to our hearts, the engineers here at Ametherm want to share their wealth of the research, development and knowledge of inrush current limiters and thermistors at a more consistent and rapid pace. What better way than to… tweet it? Or, share it on Facebook. Like us on Facebook! Follow us on Twitter! … Continue Reading
When designing a temperature detection circuit, it is important that you don’t pay for more than what is actually needed. By understanding the requirements of an application, an optimal temperature sensor can be selected that minimizes cost without compromising performance, accuracy, or reliability. There are several factors to consider when selecting a sensor. They are outlined in the table below. Temperature Sensor Selections NTC Thermistor Platinum RTD Thermocouple Semiconductor … Continue Reading
To use a temperature sensor in a control or compensation circuit, the detection circuit must provide an output in a usable format. For analog circuits, the output is usually a resistance. For digital control and compensation, the measurement needs to be converted to a digital format for processing by an MCU. This is commonly achieved by reading the measurement as a voltage using an analog to digital converter (ADC). Semiconductor-based sensors … Continue Reading
We are excited to announce that we are now offering ACCU-CURVE™ series thermistors. These are a new series of interchangeable thermistors used for temperature sensing, control, and compensation. They are best suited for applications that require a high degree of measurement accuracy over a wide temperature range. Common applications include medical, industrial, and automotive. Read the full press release here. Why choose the ACCU-CURVE™ series? The ACCU-CURVE™ series offers faster … Continue Reading
We have exciting news! U.K.- based Rhopoint Components now carries our series of NTC disc thermistors acquired from Measurement Specialties (formerly RTI electronics). These components deliver high stability and maximum sensitivity for temperature measurement, compensation, and control. You can read the full press release here. NTC Disc Thermistor Applications NTC disc thermistors offer extreme precision and temperature measurement for various applications. They are used in a wide range of industries including aerospace, military, appliance, medical, and automotive. … Continue Reading
Have you ever turned on a transformer and heard a loud humming sound? What about having a blown fuse or tripped circuit breaker? These signs can all indicate transformer inrush current. Transformer inrush current describes a spike in current that occurs when you initially turn on your transformer. This spike can be up to 10 times higher than normal current. Why does inrush current occur? It can happen because large transformers demand a huge amount of … Continue Reading
Since 1994, Ametherm has provided the most reliable and effective inrush current limiting solutions available. We deliver on that promise through innovative design, quality manufacturing, and exceptional customer support.