Product category:
Circuit Protection Devices
News Release from: Raychem Circuit Protection | Subject: PolySwitch LVR series
Edited by the Electronicstalk Editorial
Team on 23 April 2003
Resettable devices switch to primary
protection
The LVR series of PolySwitch resettable devices are designed for use in line voltage applications.
The LVR series of PolySwitch resettable devices are designed for use in line voltage applications LVR PPTC (polymeric positive temperature coefficient) devices are rated at 240V AC, permitting maximum voltages up to 265V AC, and are available in hold currents from 50 to 400mA
This article was originally published on Electronicstalk on 27 Feb 2007 at 8.00am (UK)
Related stories
Resettable fuses protect line-powered appliances
Resettable circuit protection devices help protect electric motors and transformers used in commercial and home appliances.
Resettable fuse protects latest AAAA NiMH cells
New from Raychem Circuit Protection, the MAC300 PolySwitch resettable fuse is custom designed for the new AAAA NiMH cells with increased capacity in a smaller space.
Thin strap protects thin Li-ion prismatic cells
The latest PolySwitch PPTC (polymeric positive temperature coefficient) resettable strap device from Raychem Circuit Protection offers the thinnest strap profile in the industry.
The thermally active devices can help protect against both overcurrent and overtemperature faults on the primary side of power supplies and transformers.
The LVR device was developed to help prevent damage to control boards and components by limiting current in the event of a load-side short circuit or overdraw, or improper incoming voltage.
Unlike a single-shot current fuse, the resettable LVR device can help protect against conditions where faults may cause a rise in temperature with only a slight increase in current draw.
When installed on the primary side of the circuit, in proximity to potential heat-generating components such as magnetics, FETs, or power resistors, the LVR device can help provide both overcurrent and overtemperature protection with a single installed component.
The properties of the LVR device can offer distinct benefits in transformer protection designs.
The surface temperature of the LVR device in the high-resistance state is well within the range of most transformer winding insulation ratings.
This low temperature operation, combined with small size, low resistance and good thermal shock tolerance, can allow the LVR device to be mounted in direct contact with the transformer windings for a faster response to potential fault conditions.
"For many years, circuit designers have relied on PPTC devices for secondary-side protection.
This development makes possible, for the first time, resettable PPTC circuit protection on the primary side of power circuitry", said Karin Kinsman, Product Manager for Radial-Leaded PPTC Devices for Raychem Circuit Protection.
"Higher voltage ratings and the thermal characteristics of the LVR series PolySwitch device make it a logical and innovative solution for power supply and charger designs", she added.
The LVR devices are available in straight-lead or kinked-lead configurations, and can be supplied in tape-and-reel packaging for compatibility with high-volume assembly.
The LVR parts have UL and TUV certifications, and CSA certification is currently pending.
• Raychem Circuit Protection: contact details and other news
• Email this article to a colleague
• Register for the free Electronicstalk email newsletter
• Electronicstalk Home Page
Search the Pro-Talk network of sites
