Newsletter-Autumn 2021 | High-End MELF SMD Resistors Manufacturer - FIRSTOHM

In the wake of the global outbreak of COVID-19 since 2020, many business leaders have completely rethought their operational philosophy. Not long ago, those enterprises were just considering how to implement smart manufacturing concept, which is now accelerated to accomplish as a result of the prevalence of epidemic. IoT infrastructure, combined with AI management platform and robot arm for smart production, have been accelerated in various industries, resulting in intelligent manufacturing. FIRSTOHM also began moving towards smart manufacturing last year, with the ultimate goal of increasing both production capacity and customer value. FIRSTOHM is one of the few companies who is able to design thin-film resistors according to customer's requirements with high quality and reliability. We’re specialized in MELF resistors since 1969, ISO9001/14001 certificated manufacturer.

qrc@firstohm.com.tw

On Duty: 9am - 6pm

Newsletter-Autumn 2021

FIRSTOHM Newsletter - Autumn 2021

FIRSTOHM Newsletter - Autumn 2021

Newsletter-Autumn 2021

In the wake of the global outbreak of COVID-19 since 2020, many business leaders have completely rethought their operational philosophy. Not long ago, those enterprises were just considering how to implement smart manufacturing concept, which is now accelerated to accomplish as a result of the prevalence of epidemic. IoT infrastructure, combined with AI management platform and robot arm for smart production, have been accelerated in various industries, resulting in intelligent manufacturing. FIRSTOHM also began moving towards smart manufacturing last year, with the ultimate goal of increasing both production capacity and customer value.


01 Sep, 2021 FIRSTOHM
New Releases of FIRSTOHM's Homepage
New Releases of FIRSTOHM's Homepage

Firstohm in Action

FIRSTOM completed the development of its new official website during the second quarter. The picture shows on the home page focuses on eight sectors that are suitable for using MELF resistors. Our new website has many major updates to our previous website. You can quickly preview and find relevant information here. If you have any suggestions, please leave a message on our website.

New On the Block: Superior Anti-Surge Wire Wound Axial Resistor (SSWA series)

Application
  • The soft-start resistors for Industrial Inverter.
  • Charging and discharging resistors for Electric Vehicle
  • Pre-charging resistor for Power Bank system.
  • ECG cables.
Features
  • Superior Wire Wound Resistor which is the best alternative to KOA and VISHAY
  • Special composite wire wound structures (wire wound + thin film) provide enhanced surge resistance.
  • With a low temperature coefficient and a wide temperature range, it is suitable for working in high temperature environments.
  • Approval of multi-national patents pending.
Structure

Structure

The soft-start application of Inverter

Inverter soft-start resistors are also known as current limit resistors or pre-charge resistors. The main benefit of using a soft-start circuit is to reduce the stress on the electronic components when power is ON, improve the reliability of the system, and extend the life of other components.

The soft-start circuit is connected to a high value resistances in series, and these resistors are also connected to a relay in parallel. When the Inverter is power ON, the relay is disconnected state, and the resistor restricts the current flow, which indirectly slows the rate of voltage change. When the soft-start is complete, the relays are connected and create a low resistance path, so the current will pass mainly through the relays and the system will return to normal operation, allowing for higher power.

According to the above description of the inverter's action, when the inverter is being started, the voltage rises rapidly, causing inrush current. It is therefore very important to select the right soft-start resistor. Along with long-term inrush current withstand, the FIRSTOHM SSWA series is cost-effective and offers a smaller size with more advantages than traditional aluminum resistors or cement resistors.

Case Study : The soft-start of 1.5KW Inverter

FIRSTOHM suggested alternative as below

a.) Evaluated circuit:

Evaluated circuit

b.) Test conditions:
Charging RES. : SSWA05S,120R,5%
Input voltage: 746.7V
Capacitor: 220uF
Ambient temperature: 85℃
Charge/Discharge: ac: 59 SEC. & bc: 1 SEC.
Number of switching: 100,000

c.) Test result: Passed !
Pre-test: 123.44Ω
Post-test: 124.17Ω
△R: +0.591%

Download
What's New At Firstohm-Autumn 2021
What's New At Firstohm-Autumn 2021

Soft-start Resistor for Inverter (Industrial Automoation)

Download
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High-End MELF SMD Resistors Manufacturer - FIRSTOHM

Located in Taiwan since 1969, First resistor & condenser Co. Ltd. is a MELF type resistor manufacturer. ISO9001/14001 certificated, award winning and patented design thin-film resistors, including anti-surge resistor, precision resistor, stability resistor, high voltage resistor, current sense resistor, automotive grade resistor, high power resistor, circuit protection resistor, fusible resistor and so forth.

FIRSTOHM's resistors are being widely used in industry applications, such as power supply, telecom, meter, medical, automotive and lighting. The strong R&D has allowed FIRSTOHM to develop new technology and obtain hundreds of patents, as well as develop specialty resistors, such as high voltage resistor, short circuit protection resistor, dual power resistor, high humidity resistor, etc.

FIRSTOHM has been offering customers high quality MELF resistors since 1969, both with advanced technology and 50 years of experience, FIRSTOHM ensures each customer's demands are met.