Facebook Twitter Linkedin Youtube

Free Samples | Reed Relay Selection Tool | Shipping Worldwide*

  • MY ACCOUNT
Menu
  • MY ACCOUNT
Login
logo

50 years of designing, manufacturing & distributing quality Reed Relays

T +44 (0) 1255 428 141
Email: sales@pickeringrelay.com

Pickering Electronics Ltd
Stephenson Rd, Clacton, Essex, England, CO15 4NL

Open in Google Maps

Facebook Twitter Linkedin Youtube
  • About
    • About
      • 10 Key Benefits of Pickering Reed Relays
      • Why Pickering Reed Relays?
      • 50 Years of Quality Reed Relays
      • Reed Relay Timeline
      • Pickering Interfaces
    • Quality Assurance
    • Careers
    • Brexit Statement
    • COVID-19 Notice
    • Ukraine Conflict
  • Reed Relays
    • By Series No.
      • Single-In-Line (SIL/SIP) Series 100 – 110
        • 100 – Low Thermal EMF Relays
        • 100HV – HV up to 3kV – High Coil Resistance
        • 100HC – 3A High Carry Current / High Coil Resistance
        • 101 – Direct Drive From CMOS
        • 102 – Up to 20W Coaxial RF/High Speed Digital
        • 103 – Low Capacitance – Wide Bandwidth
        • 104 – HV 1kV Switching, 4kV Stand-Off
        • 105 – 20W (Dry) & 50W (Mercury)
        • 106 – 0.2” x 0.8” up to 20W + HV 1.5kV Stand-off
        • 107 – Mu-metal Standard Size up to 20W
        • 108 – 0.15” x 0.8” Mu-Metal Screened Relay
        • 109 – 0.15” x 0.6” – Up to 20W + RF
        • 110 – 0.15” x 0.4” – Up to 20W
      • Single-In-Line (SIL) Series 111-131
        • 111 – 0.15” x 0.4” 10W + 2.5GHz RF
        • 112 – 0.15” x 0.4” 10W High Density
        • 113 – 0.15” x 0.5” 3W (Form C),
          10W (Form A) + 3 GHz RF
        • 114 – 40W High Power SIP
        • 115 – Up to 1 Amp, 20W High Density
        • 116 – 0.5A, 10W Very High Density
        • 117 – 0.5A, 10W Very High Density
        • 118 – High Coil Resistance – Small Size
        • 119 – Up to 3KV Stand-off – Mini High Voltage
        • 131 – 10W 1.5kV Stand-off PCB Smallest HV SIP
      • High Voltage (HV) Relays
        • 62 & 63: 15kV PCB/Chassis Mount Push On Terminals
        • 60 & 65 – 15kV PCB/Chassis Mount Solder Terminals
        • 67 & 68 – 200W 10kV PCB/Flying Lead Connections
        • 100HV – HV up to 3kV – High Coil Resistance
        • 104 – 25W 1kV Switching, 4kV Stand-off PCB SIP
        • 119 – 10W 1kV Switching, 3kV Stand-off PCB Mini SIP
        • 131 – 10W 1.5kV Stand-off PCB Smallest HV SIP
      • Ultra-High Density 4mm Relays
        • 120 – 1 Amp, 20W 4mm X 15.5mm
        • 122 – 0.5 Amp, 10W 4mm X 12.5mm
        • 124 – 0.5A, 10W 4mm X 9.5mm
      • Dual-in-Line (DIL/DIP) Series 97 – 98
        • 97 – Dry 3W (Form C) 10W (Form A), Mercury 50W
        • 98 – 3W (Form C) 20W (Form A) CMOS Direct Drive
      • Legacy / Classic Relays
        • Older Style Relays – Series 80, 85, 88 & 89
        • Older Style Relays – Series 86 and 87
      • Surface Mount
    • By Application
      • High Density
      • High Voltage
        • Cable Testing
        • Mining Gas Analysis
      • General Instrumentation
      • RF Fast / Digital
      • Portable Equipment
      • High Power
      • Data Acquisition
      • Low Thermal EMF
      • Thermocouple Switching
      • Direct Drive from CMOS
      • Low Capacitance
    • Reed Relay Selector Tool
    • Custom Reed Relays
  • How to Buy
    • Request a Quote
    • Buy Online
    • Free Evaluation Samples
    • Distributors & Sales Offices
    • Distributor Inventory
  • Resources
    • Application Guides
      • Photovoltaic Efficiency & Fault Detection
      • EV & Charge Point Testing
    • Reed Relay Selector Tool
    • Data Sheets
    • Concise Tech Guide
    • Relay Catalogue
    • RelayMate Book
    • Relay Finder Map
    • 3D Relay Models
    • Videos
  • News
    • Product News
    • Media News
    • Events
  • Support
    • Contact Us
    • General Help
      • Technical Help
      • RelayMate Book
      • SoftCenter ®
      • Connectivity Advice
      • Magnetic Interaction
      • Glossary of Terms
Menu
  • About
    • About
      • 10 Key Benefits of Pickering Reed Relays
      • Why Pickering Reed Relays?
      • 50 Years of Quality Reed Relays
      • Reed Relay Timeline
      • Pickering Interfaces
    • Quality Assurance
    • Careers
    • Brexit Statement
    • COVID-19 Notice
    • Ukraine Conflict
  • Reed Relays
    • By Series No.
      • Single-In-Line (SIL/SIP) Series 100 – 110
        • 100 – Low Thermal EMF Relays
        • 100HV – HV up to 3kV – High Coil Resistance
        • 100HC – 3A High Carry Current / High Coil Resistance
        • 101 – Direct Drive From CMOS
        • 102 – Up to 20W Coaxial RF/High Speed Digital
        • 103 – Low Capacitance – Wide Bandwidth
        • 104 – HV 1kV Switching, 4kV Stand-Off
        • 105 – 20W (Dry) & 50W (Mercury)
        • 106 – 0.2” x 0.8” up to 20W + HV 1.5kV Stand-off
        • 107 – Mu-metal Standard Size up to 20W
        • 108 – 0.15” x 0.8” Mu-Metal Screened Relay
        • 109 – 0.15” x 0.6” – Up to 20W + RF
        • 110 – 0.15” x 0.4” – Up to 20W
      • Single-In-Line (SIL) Series 111-131
        • 111 – 0.15” x 0.4” 10W + 2.5GHz RF
        • 112 – 0.15” x 0.4” 10W High Density
        • 113 – 0.15” x 0.5” 3W (Form C),
          10W (Form A) + 3 GHz RF
        • 114 – 40W High Power SIP
        • 115 – Up to 1 Amp, 20W High Density
        • 116 – 0.5A, 10W Very High Density
        • 117 – 0.5A, 10W Very High Density
        • 118 – High Coil Resistance – Small Size
        • 119 – Up to 3KV Stand-off – Mini High Voltage
        • 131 – 10W 1.5kV Stand-off PCB Smallest HV SIP
      • High Voltage (HV) Relays
        • 62 & 63: 15kV PCB/Chassis Mount Push On Terminals
        • 60 & 65 – 15kV PCB/Chassis Mount Solder Terminals
        • 67 & 68 – 200W 10kV PCB/Flying Lead Connections
        • 100HV – HV up to 3kV – High Coil Resistance
        • 104 – 25W 1kV Switching, 4kV Stand-off PCB SIP
        • 119 – 10W 1kV Switching, 3kV Stand-off PCB Mini SIP
        • 131 – 10W 1.5kV Stand-off PCB Smallest HV SIP
      • Ultra-High Density 4mm Relays
        • 120 – 1 Amp, 20W 4mm X 15.5mm
        • 122 – 0.5 Amp, 10W 4mm X 12.5mm
        • 124 – 0.5A, 10W 4mm X 9.5mm
      • Dual-in-Line (DIL/DIP) Series 97 – 98
        • 97 – Dry 3W (Form C) 10W (Form A), Mercury 50W
        • 98 – 3W (Form C) 20W (Form A) CMOS Direct Drive
      • Legacy / Classic Relays
        • Older Style Relays – Series 80, 85, 88 & 89
        • Older Style Relays – Series 86 and 87
      • Surface Mount
    • By Application
      • High Density
      • High Voltage
        • Cable Testing
        • Mining Gas Analysis
      • General Instrumentation
      • RF Fast / Digital
      • Portable Equipment
      • High Power
      • Data Acquisition
      • Low Thermal EMF
      • Thermocouple Switching
      • Direct Drive from CMOS
      • Low Capacitance
    • Reed Relay Selector Tool
    • Custom Reed Relays
  • How to Buy
    • Request a Quote
    • Buy Online
    • Free Evaluation Samples
    • Distributors & Sales Offices
    • Distributor Inventory
  • Resources
    • Application Guides
      • Photovoltaic Efficiency & Fault Detection
      • EV & Charge Point Testing
    • Reed Relay Selector Tool
    • Data Sheets
    • Concise Tech Guide
    • Relay Catalogue
    • RelayMate Book
    • Relay Finder Map
    • 3D Relay Models
    • Videos
  • News
    • Product News
    • Media News
    • Events
  • Support
    • Contact Us
    • General Help
      • Technical Help
      • RelayMate Book
      • SoftCenter ®
      • Connectivity Advice
      • Magnetic Interaction
      • Glossary of Terms
$0.00 0 Basket
Shop




Now
  • About
    • About
      • 10 Key Benefits of Pickering Reed Relays
      • Why Pickering Reed Relays?
      • 50 Years of Quality Reed Relays
      • Reed Relay Timeline
      • Pickering Interfaces
    • Quality Assurance
    • Careers
    • Brexit Statement
    • COVID-19 Notice
    • Ukraine Conflict
  • Reed Relays
    • By Series No.
      • Single-In-Line (SIL/SIP) Series 100 – 110
        • 100 – Low Thermal EMF Relays
        • 100HV – HV up to 3kV – High Coil Resistance
        • 100HC – 3A High Carry Current / High Coil Resistance
        • 101 – Direct Drive From CMOS
        • 102 – Up to 20W Coaxial RF/High Speed Digital
        • 103 – Low Capacitance – Wide Bandwidth
        • 104 – HV 1kV Switching, 4kV Stand-Off
        • 105 – 20W (Dry) & 50W (Mercury)
        • 106 – 0.2” x 0.8” up to 20W + HV 1.5kV Stand-off
        • 107 – Mu-metal Standard Size up to 20W
        • 108 – 0.15” x 0.8” Mu-Metal Screened Relay
        • 109 – 0.15” x 0.6” – Up to 20W + RF
        • 110 – 0.15” x 0.4” – Up to 20W
      • Single-In-Line (SIL) Series 111-131
        • 111 – 0.15” x 0.4” 10W + 2.5GHz RF
        • 112 – 0.15” x 0.4” 10W High Density
        • 113 – 0.15” x 0.5” 3W (Form C),
          10W (Form A) + 3 GHz RF
        • 114 – 40W High Power SIP
        • 115 – Up to 1 Amp, 20W High Density
        • 116 – 0.5A, 10W Very High Density
        • 117 – 0.5A, 10W Very High Density
        • 118 – High Coil Resistance – Small Size
        • 119 – Up to 3KV Stand-off – Mini High Voltage
        • 131 – 10W 1.5kV Stand-off PCB Smallest HV SIP
      • High Voltage (HV) Relays
        • 62 & 63: 15kV PCB/Chassis Mount Push On Terminals
        • 60 & 65 – 15kV PCB/Chassis Mount Solder Terminals
        • 67 & 68 – 200W 10kV PCB/Flying Lead Connections
        • 100HV – HV up to 3kV – High Coil Resistance
        • 104 – 25W 1kV Switching, 4kV Stand-off PCB SIP
        • 119 – 10W 1kV Switching, 3kV Stand-off PCB Mini SIP
        • 131 – 10W 1.5kV Stand-off PCB Smallest HV SIP
      • Ultra-High Density 4mm Relays
        • 120 – 1 Amp, 20W 4mm X 15.5mm
        • 122 – 0.5 Amp, 10W 4mm X 12.5mm
        • 124 – 0.5A, 10W 4mm X 9.5mm
      • Dual-in-Line (DIL/DIP) Series 97 – 98
        • 97 – Dry 3W (Form C) 10W (Form A), Mercury 50W
        • 98 – 3W (Form C) 20W (Form A) CMOS Direct Drive
      • Legacy / Classic Relays
        • Older Style Relays – Series 80, 85, 88 & 89
        • Older Style Relays – Series 86 and 87
      • Surface Mount
    • By Application
      • High Density
      • High Voltage
        • Cable Testing
        • Mining Gas Analysis
      • General Instrumentation
      • RF Fast / Digital
      • Portable Equipment
      • High Power
      • Data Acquisition
      • Low Thermal EMF
      • Thermocouple Switching
      • Direct Drive from CMOS
      • Low Capacitance
    • Reed Relay Selector Tool
    • Custom Reed Relays
  • How to Buy
    • Request a Quote
    • Buy Online
    • Free Evaluation Samples
    • Distributors & Sales Offices
    • Distributor Inventory
  • Resources
    • Application Guides
      • Photovoltaic Efficiency & Fault Detection
      • EV & Charge Point Testing
    • Reed Relay Selector Tool
    • Data Sheets
    • Concise Tech Guide
    • Relay Catalogue
    • RelayMate Book
    • Relay Finder Map
    • 3D Relay Models
    • Videos
  • News
    • Product News
    • Media News
    • Events
  • Support
    • Contact Us
    • General Help
      • Technical Help
      • RelayMate Book
      • SoftCenter ®
      • Connectivity Advice
      • Magnetic Interaction
      • Glossary of Terms
Menu
  • About
    • About
      • 10 Key Benefits of Pickering Reed Relays
      • Why Pickering Reed Relays?
      • 50 Years of Quality Reed Relays
      • Reed Relay Timeline
      • Pickering Interfaces
    • Quality Assurance
    • Careers
    • Brexit Statement
    • COVID-19 Notice
    • Ukraine Conflict
  • Reed Relays
    • By Series No.
      • Single-In-Line (SIL/SIP) Series 100 – 110
        • 100 – Low Thermal EMF Relays
        • 100HV – HV up to 3kV – High Coil Resistance
        • 100HC – 3A High Carry Current / High Coil Resistance
        • 101 – Direct Drive From CMOS
        • 102 – Up to 20W Coaxial RF/High Speed Digital
        • 103 – Low Capacitance – Wide Bandwidth
        • 104 – HV 1kV Switching, 4kV Stand-Off
        • 105 – 20W (Dry) & 50W (Mercury)
        • 106 – 0.2” x 0.8” up to 20W + HV 1.5kV Stand-off
        • 107 – Mu-metal Standard Size up to 20W
        • 108 – 0.15” x 0.8” Mu-Metal Screened Relay
        • 109 – 0.15” x 0.6” – Up to 20W + RF
        • 110 – 0.15” x 0.4” – Up to 20W
      • Single-In-Line (SIL) Series 111-131
        • 111 – 0.15” x 0.4” 10W + 2.5GHz RF
        • 112 – 0.15” x 0.4” 10W High Density
        • 113 – 0.15” x 0.5” 3W (Form C),
          10W (Form A) + 3 GHz RF
        • 114 – 40W High Power SIP
        • 115 – Up to 1 Amp, 20W High Density
        • 116 – 0.5A, 10W Very High Density
        • 117 – 0.5A, 10W Very High Density
        • 118 – High Coil Resistance – Small Size
        • 119 – Up to 3KV Stand-off – Mini High Voltage
        • 131 – 10W 1.5kV Stand-off PCB Smallest HV SIP
      • High Voltage (HV) Relays
        • 62 & 63: 15kV PCB/Chassis Mount Push On Terminals
        • 60 & 65 – 15kV PCB/Chassis Mount Solder Terminals
        • 67 & 68 – 200W 10kV PCB/Flying Lead Connections
        • 100HV – HV up to 3kV – High Coil Resistance
        • 104 – 25W 1kV Switching, 4kV Stand-off PCB SIP
        • 119 – 10W 1kV Switching, 3kV Stand-off PCB Mini SIP
        • 131 – 10W 1.5kV Stand-off PCB Smallest HV SIP
      • Ultra-High Density 4mm Relays
        • 120 – 1 Amp, 20W 4mm X 15.5mm
        • 122 – 0.5 Amp, 10W 4mm X 12.5mm
        • 124 – 0.5A, 10W 4mm X 9.5mm
      • Dual-in-Line (DIL/DIP) Series 97 – 98
        • 97 – Dry 3W (Form C) 10W (Form A), Mercury 50W
        • 98 – 3W (Form C) 20W (Form A) CMOS Direct Drive
      • Legacy / Classic Relays
        • Older Style Relays – Series 80, 85, 88 & 89
        • Older Style Relays – Series 86 and 87
      • Surface Mount
    • By Application
      • High Density
      • High Voltage
        • Cable Testing
        • Mining Gas Analysis
      • General Instrumentation
      • RF Fast / Digital
      • Portable Equipment
      • High Power
      • Data Acquisition
      • Low Thermal EMF
      • Thermocouple Switching
      • Direct Drive from CMOS
      • Low Capacitance
    • Reed Relay Selector Tool
    • Custom Reed Relays
  • How to Buy
    • Request a Quote
    • Buy Online
    • Free Evaluation Samples
    • Distributors & Sales Offices
    • Distributor Inventory
  • Resources
    • Application Guides
      • Photovoltaic Efficiency & Fault Detection
      • EV & Charge Point Testing
    • Reed Relay Selector Tool
    • Data Sheets
    • Concise Tech Guide
    • Relay Catalogue
    • RelayMate Book
    • Relay Finder Map
    • 3D Relay Models
    • Videos
  • News
    • Product News
    • Media News
    • Events
  • Support
    • Contact Us
    • General Help
      • Technical Help
      • RelayMate Book
      • SoftCenter ®
      • Connectivity Advice
      • Magnetic Interaction
      • Glossary of Terms
  • Home
  • News Archive
  • Media News
  • Reinforce Design Reliability with Reed Relays

Reinforce Design Reliability with Reed Relays

by pickering / Saturday, 24 September 2016 / Published in Media News

If used correctly, a reed relay is a superbly reliable device. The switch contacts are hermetically sealed, so they don’t suffer from oxidization or contamination in the same way as an open electromechanical relay.

In reality, relays are often considered slightly mundane and little thought is given to them, which sometimes leaves them vulnerable. This guide will help you to maximize the reliability of your design.

Contact Abuse

High-current or high-power inrushes are the most damaging and most frequent cause of contact damage. Reed relays have specified maximum current, voltage, and power ratings. The power figure is simply the product of the voltage across the open contacts before closure and the instantaneous current they first make.

We at Pickering have lost count of the number of times that we’ve heard something like, “I was only switching 5 V at 50 mA onto this CMOS logic board,” when the user has completely disregarded the current inrush into the liberal sprinkling of decoupling capacitors and several microfarads of reservoir capacitance on that board.

Don’t rely solely on electronic current limiting of power supplies to protect relay contacts. Electronic current limiting takes a finite time to react, and decoupling capacitors are often on the output of a power supply. There’s nothing better than resistive current limiting.

As well as inrushes due to charging capacitive loads, discharging capacitors can be an even greater issue since the current is often only limited by the resistance of the reed switch and PC tracks. Even capacitors charged to quite low voltages can cause current inrushes of tens of amps. And, although they may be for microseconds only, such capacitors can cause damage to small reed switches.

As voltages increase for some applications, inrushes can become an even greater issue; for example, when discharging cables after high-voltage proof testing. The energy stored in capacitance is equal to ½ CV2 joules, so it will increase with the square of voltage. Increasing from 10 to 1000 V will boost the stored energy by 10,000 times.

If you’ve ever had a relay contact stick closed, only to free up with a slight tap, or had a longer than expected release time, then more than likely it’s caused by a micro-weld due to a current inrush.

“Hot” vs. “Cold” Switching

Reed relays generally have a higher carry-current rating than their “hot” switching-current rating. Contact damage usually occurs during “hot” switching due to the resulting arc across the contacts as they open or close. A severe current overload will quickly melt the contact area, causing the two surfaces to fuse together, creating a hard weld as soon as the contact closes.

Less severe current inrushes will cause a milder weld or gradually build up a “pip” on one contact and erode a “crater” on the other, according to the direction of current flow. These can eventually lock together. Arcs can occur when contacts open, particularly when the load is inductive. Back EMFs from inductive loads should always be limited, usually with a simple diode in the case of dc loads, or by a snubber or varistor for ac loads.

One way to reduce or remove these issues is to “cold” switch. This is a common technique in test instrumentation, where the current or voltage stimulus isn’t applied to the switch until after the relay has been operated and contact bounce is finished. In the same way, the stimulus is removed before the contact is opened. Therefore, no arcing or switched current inrushes will occur, and the relay will achieve maximum life, often into billions of operations.

When calculating the delay time between switching on the relay coil and applying the current to the switch, it’s important to consider the effects of high ambient temperature if it appears likely to occur. The maximum operate time and bounce figures given on datasheets are at a 25°C ambient level. At higher temperatures, the resistance of the coil winding will increase at a rate of 0.4%/°C, this being the coefficient of resistance of the copper coil wire. Correspondingly, both the coil current and level of the magnetic field generated to operate the reed switch will fall. This lower drive level will increase the operate time slightly.

The timing figures on datasheets are normally quite conservative, so this is unlikely to be an issue up to the normal ambient specification of 85°C. However, if there’s any additional self-heating within the relay due to a high carry current and switch resistance (I2R W), it will be necessary to consider this and allow a little more time before turning on the current through the switch.

You can view the original article here.

About pickering

Pickering Electronics have been specialising in high-quality instrumentation grade Reed Relay designs for over 50 years and are eager to share their technical expertise. Pickering relays are sold in high volumes to automatic test equipment companies throughout the world.

What you can read next

Wiselink Singapore
Pickering Electronics signs with Wiselink in Singapore, Malaysia and Thailand
Miniature HV Reed Relay
Pickering Electronics’ Miniature HV Reed Relay at the Heart of IC Test System for On Semiconductor.
Pickering Series 119
Single-in-Line reed relays are ‘industry’s smallest’

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Try our new selector tool

Try the Reed Relay Selector

Join our newsletter

What is a Reed Relay?

https://www.youtube.com/watch?v=zTbv5szQNoA&t=12s
Celebrating 50 years of Pickering Electronics

Reed Relays

  • High Density Reed Relays
  • High Voltage Reed Relays
  • Coaxial RF Reed Relays
  • General Instrumentation Reed Relays
  • High Power Reed Relays
  • Reed Relay Selector Tool
  • High Density Reed Relays
  • High Voltage Reed Relays
  • Coaxial RF Reed Relays
  • General Instrumentation Reed Relays
  • High Power Reed Relays
  • Reed Relay Selector Tool

Support

  • Quotation Request
  • Free Reed Relay Sample Service
  • Literature & Technical Guides
  • General Technical Help
  • Find a Local Representative
  • Quality Assurance & ISO Certificates
  • Quotation Request
  • Free Reed Relay Sample Service
  • Literature & Technical Guides
  • General Technical Help
  • Find a Local Representative
  • Quality Assurance & ISO Certificates

Company Information

  • About Pickering
  • 10 Key Benefits of Pickering Relays
  • Contact Us
  • Pickering in the News
  • Shipping & Delivery Information
  • Join our Newsletter to Keep Up-to-Date
  • About Pickering
  • 10 Key Benefits of Pickering Relays
  • Contact Us
  • Pickering in the News
  • Shipping & Delivery Information
  • Join our Newsletter to Keep Up-to-Date

Follow us on social media

Facebook-f Twitter Linkedin Youtube

© 2021 Copyright Pickering Electronics Ltd, Stephenson Rd, Clacton, Essex, England, CO15 4NL. All rights reserved.

Terms and Conditions | Return Policy | Privacy Policy | Cookie Policy

SIGN IN YOUR ACCOUNT TO HAVE ACCESS TO DIFFERENT FEATURES

Forgot password?

Sign In