Trimmer potentiometers and their application
5 October 2005
Passive Components
Information from Avnet Kopp
The applications of trimmer potentiometers are roughly divided into the following two categories: voltage division adjustment - where a certain voltage is obtained from the ratio of the resistance; current adjustment - where a current value is determined from the magnitude of resistance.
Resistive elements are available in two types: carbon and cermet (ceramic-metal):
* With the carbon resistive element type, the long-term change of the resistance as a result of exposure to high temperature or humidity is rather great. However, since the resistance changes uniformly throughout the entire resistor, the ratio of the resistance (resistance setting stability, or RSS) barely changes. Therefore, this type is generally used for voltage division adjustment. However, when the total resistance change (fluctuation TR) is within the circuit tolerance, this type may also be used for current adjustment application.
* With the cermet resistive element type, the long-term change of the resistance as a result of exposure to high temperature or humidity is small. Therefore, this type is used both for voltage division adjustment and current adjustment.
Murata has available the PVZ3 Series carbon resistive element trimmer potentiometers and PVA3 Series cermet resistive element trimmer potentiometers. Environmental test graphs showing the change in resistance over time (1000 hrs) are available from the distributor to aid the design choice.
Further reading:
Harnessing Leakage Inductance
Würth Electronics South Africa
Passive Components
Würth Electronics has expanded its WE-MCRI product series with the new 1090HL variant (HL = High Leakage), a coupled inductor specifically designed to improve the performance of SEPIC, ZETA and Cuk converters.
Read more...
Ultra-slim 30 W DIN Rail AC/DC
Brabek
Passive Components
RECOM is extending its REFIN family with the new REFIN2U-S30.
Read more...
Panasonic thick film current sense resistors
Avnet Abacus
Passive Components
Panasonic thick film current sense resistors enable potential cost savings up to 50% as an alternative to metal shunts
Read more...
Space saving SMD common-mode chokes
Electrocomp
Passive Components
TDK Corporation presents the EP21 series of flat-wire double chokes designed for common-mode EMI filtering and available in an SMD format with dimensions of only 23,8 x 17,7 mm and heights ranging from 21,6 to 22,3 mm
Read more...
Highly rugged GAPS and HAPS proximity sensors
IOT Electronics
Passive Components
Now available through Powell Electronics are the GAPS (General Aerospace Proximity Sensors) and HAPS (Harsh Application Proximity Sensors) proximity sensors from Honeywell.
Read more...
Understanding EMI Filters and their applications
Vepac Electronics
Passive Components
Electromagnetic Interference (EMI) Filters are essential for maintaining electromagnetic compatibility (EMC), allowing multiple devices to function together without interference.
Read more...
SMT flat-wire inductor
Passive Components
Würth Elektronik introduces its new WE-SFIA series of flat-wire inductors in 2010, 2013, and 2016 packages.
Read more...
Compact SSI family for industrial automation
Altron Arrow
Passive Components
Infineon Technologies has introduced the ISSI20BxxF Solid State Isolator (SSI) family, bringing solid-state isolation technology into high-volume applications traditionally served by photovoltaic isolators (PVIs), photovoltaic relays (PVRs), and electromechanical relays (EMRs).
Read more...
SGMICRO expands analogue IC portfolio
iCorp Technologies
Passive Components Telecoms, Datacoms, Wireless, IoT
SGMICRO continues to add to its analogue IC portfolio at a steady pace, with new devices released across power protection, power conversion, current sensing and RF signal-chain categories.
Read more...
SMT flat-wire inductor for automotive electronics
Würth Electronics South Africa
Passive Components
Würth Elektronik introduces its new WE-SFIA series of flat-wire inductors in 2010, 2013, and 2016 packages.
Read more...
printer friendly version