Pickering Electronics Blog

Kevin Mallett

Technical Manager at Pickering Electronics Ltd
Find me on:

Recent Posts

Understanding Reed Relay Terminology

Posted by Kevin Mallett on Mar 23, 2016 12:30:00 AM


The relay industry has evolved with a set of its own nomenclature that describes the products available, however, not all of these terms are familiar to users. The following blog post seeks to describe and explain these relay terms.


Form A

Form A describes a relay whereby the contact is a simple switch, which is open or closed, and the un-energised position is the open condition. For a single relay this would also be described as a single pole, single throw (SPST) relay with a normally open (NO) contact.

If the relay has multiple contacts in the same package it would be described as having (for example) 2 Form A contacts (DPST).

Pickering has a range of  Form A Reed Relays, for example our Series 109 that are an ideal choice for high density applications, or our high voltage Series 104 for up to 3kV.

Read More

Topics: Reed Relays, Form B, Form A, Form C

Choosing a Reed Relay

Posted by Kevin Mallett on Sep 28, 2015 11:30:00 AM


The following blog post describes and recommends the key features an engineer should consider when choosing a Reed Relay.


Signal Voltage, Current and Power Specification

All reed relays have specified voltage and current ratings that need to be kept within if the reed relay is to have a long service life. It important to be clear if the application envisages hot switch or cold switching, it can have a substantial impact on the cost and size of relay used. If hot switching is likely to occur note the power rating of the reed relay, the fact a particular relay may be capable of 100V and 1A does not mean it can hot switch a signal with these extremes. At 100V a 10W reed relay will only switch 100mA reliably.

If hot switching is not expected then the user can rely on the carry current rating and the rated withstand voltage across the contacts.

SMD or Thru Hole Mounting

For applications where relays may have to be serviced Pickering Electronics recommend thru hole components are used. Outside of this the choice is driven by user manufacturing preferences and component choices such as footprint area, relay ratings and relay height.

Read More

Topics: Reed Relays, Hot Switching, RF Relays

High Voltage Micro-SIL Reed Relays

Posted by Kevin Mallett on Jul 15, 2015 12:30:00 PM


Reed Relays remain an attractive solution for switching applications. Having a metallic path, they do not suffer from the relatively high and non-linear contact resistance together with the high off-state leakage current usually associated with solid state relays.

High voltage reed relays are intended for applications where the voltages are beyond the capabilities of conventional reed relays. They use vacuum reed switches to maximise the voltage rating for a given blade separation and to manage arc duration as the contacts open or close.

Any loss of seal will rapidly degrade the switch operation so reed switches have to be carefully managed as they are packaged into reed relays, using suitable encapsulation materials and Pickering’s SoftCenter® technology. The relay design must ensure there is adequate clearance distance both internally and externally for the rated voltages, something which also needs to be considered for the PCB layout.


Read More

Topics: Reed Relays, High Voltage, Dry Reed Relays, Micro-SIL