REED RELAYS FOR DIRECT DRIVE FROM CMOS
Pickering’s Series 100 and 101 have low levels of thermal EMF for improved resolution when used to switch thermocouples.
Where available drive currents are significantly lower than Transistor-Transistor Logic (TTL), for example 4000B Complementary Metal-Oxide Semiconductor (CMOS),74HC/HCT logic or similar low current sources, there is not enough current to operate standard reed relays or electromechanical relays (EMRs) without an additional driver.
A typically 500 Ohms, 5 Volt reed relay will require 10mA drive current, and even small, 5 Volt electromechanical relays can require 30mA or more. Pickering Series 100 and Series 101 reed relays require significantly less drive current, for a single form A relay with a 5 Volt coil, the Series 100 will require only 1.5mA and Series 101 only 3.1mA. Both ranges offer 12 and 24 Volt coil options, and the Series 101 also offers a 3000 Ohm 5 Volt coil option requiring just 1.7mA.
The Series 100 and Series 101 offer 1 Form A, 2 Form A, 1 Form B and 1 Form C configurations, all featuring magnetic screening to allow for side-by-side stacking and instrumentation grade reed switches to ensure long life. The high coil resistances reduces heat in the package resulting in excellent thermal EMF performance and the low coil power consumption also makes these reed relays ideal for portable equipment.
Recommended Reed Relays for Direct Drive from CMOS
Series 100 – Low Thermal EMF
Thermal EMF about 1 Microvolt or Less. 1 Form A, 2 Form A, 1 Form B & 1 Form C configurations. 3, 5, 12 or 24 V coils. Low power consumption, ideal for portable equipment.
The Pickering Series 100 is a complete range of Single-in- Line (SIL) reed relays primarily intended for direct drive from 4000B CMOS or NMOS logic or similar low current sources. They are also useful for applications where conservation of current is important, for example, battery powered equipment.
Series 101 – Direct Drive from CMOS
Direct drive from 74HC or HCT. Stacking on 0.3 inches pitch. 1 Form A, 2 Form A, 1 Form B & 1 Form C configurations. 3, 5, 12 or 24 V coils. Encapsulated in a plastic package with internal mu-metal magnetic screen.
The Series 101 have very high coil resistances. 5 Volt dry versions may be driven directly from 74HC or 74HCT logic without the need for additional drivers. 74HC logic will drive up to 4mA at 5 Volts, therefore a coil resistance of 1600 ohms is desirable to avoid running the IC at its maximum rating; 1600 ohms is the coil resistance of the single pole dry Series 101.
Shop Reed Relays for Direct Drive from CMOS
The below table will help you narrow down our offering to get you the correct reed relay for your application.
Once you narrow your selections down you can download a reed relay data sheet for more information or request a quote to find out prices and lead times.
Part Number |  | Contact Configuration | Switching Current (Amps) | Switching Power (Watts) | Switching Voltage (DC or AC peak) | Stand-off Voltage (DC or AC peak) | Coil Voltage | Coil Resistance (Ω) | Switch Type | Diode | Depth (mm) | Width (mm) | Height (mm) | View Datasheet | Stock | Price | Add to Bag |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
 | 1 Form A - SPST N.O. | 0.5 Amps | 10 | 500 | 1000 | 24V | 6800 Ω | 1000V Stand-off | Yes | 10.2 | 24.1 | 12.7 | 296 | $16.63 | |||
| 1 Form A - SPST N.O. | 2 Amps | 50 | 500 | 550 | 5V | 370 Ω | Std Mercury Reed | Yes | 10.2 | 24.1 | 12.7 | 4 | $65.91 | |||
 | 1 Form B - SPST N.C. | 1 Amps | 20 | 200 | 240 | 12V | 6000 Ω | General Dry Reed | No | 10.2 | 24.1 | 15.2 | 0 - MTO | $16.74 | |||
| 2 Form A - DPST N.O. | 2 Amps | 50 | 500 | 550 | 24V | 3300 Ω | Std Mercury Reed | No | 10.2 | 24.1 | 15.2 | 0 - MTO | $128.17 | |||
| 1 Form A - SPST N.O. | 0.5 Amps | 10 | 200 | 240 | 5V | 3300 Ω | Low Level | Yes | 10.2 | 24.1 | 12.7 | 0 - MTO | $12.43 | |||
| 2 Form A - DPST N.O. | 0.5 Amps | 10 | 200 | 240 | 12V | 6000 Ω | Low Level Dry Reed | Yes | 10.2 | 24.1 | 15.2 | 39 | $15.73 | |||
| 1 Form A - SPST N.O. | 0.5 Amps | 10 | 500 | 1000 | 24V | 6800 Ω | 1000V Stand-off | No | 10.2 | 24.1 | 12.7 | 0 - MTO | $15.69 |
