SERIES 420/422 MAGNETIC-LATCHING ESTABLISHED RELIABILITY TO-5 RELAYS DPDT

Category: Electronics, Relays, Teledyne Technologies Incorporated

Description

The Series 420/422 relays from Teledyne Relays are magnetic-latching, double-pole double-throw (DPDT) TO-5 relays designed for established reliability. These relays are identifiable by their small size, low coil power dissipation, and flexibility for a wide range of applications including high-density PC board mounting.

The 4200/422D and 420DD/422DD models incorporate internal discrete diodes for coil suppression and polarity reversal protection. Prominent for their applications in Radio Frequency (RF) switching, particularly in handheld radio receivers, these TO-5 relays demonstrate superior performance, particularly for the UHF spectrum.

Features and Benefits

Key features making the Series 420/422 relays reliable include: all-welded construction, unique uni-frame design for high magnetic efficiency and mechanical rigidity, high force/mass ratios for shock and vibration resistance, and advanced cleaning processes for internal cleanliness. The contacts are made of a precious metal alloy with gold plating to ensure high current and dry circuit switching capabilities.

Principle of Operation

Operation of the relays involves energizing the coil to produce a magnetic field that either opposes or reinforces the holding flux of a permanent magnet. This interaction controls the armature position, thus opening or closing the contacts without requiring continuous power, thanks to the magnetic latching mechanism. Correct polarity must be applied to the relay coils as per the schematic for proper functioning.

Magnetic Latching Feature

Magnetic latching provides a “memory” function; the relay position is maintained even when coil power is removed. However, particular care must be taken not to pulse latch and reset coils simultaneously, and the relay coils must be pulsed with at least the rated coil voltage and a sufficient pulse width to guarantee reliable operation.

Environmental and Physical Specifications

The Series 420/422 relays can endure a wide range of environmental conditions with operating temperatures ranging from -65°C to +125°C. They are highly resistant to vibration, enduring up to 30 g’s to 3000 Hz, and can withstand shock up to 100 g’s for 6 milliseconds as per the general notes. Additionally, the relays boast a hermetically sealed enclosure, helping to maintain performance in various environments, and weigh a maximum of 0.10 oz (2.84g).

Note

Specifications mentioned in this datasheet are subject to change without notice, for the most accurate and updated information, users are advised to visit Teledyne Relays’ official website.