The Pickering Series 98 is a range of Dual-In-Line relays, electrically equivalent to the Series 101 CMOS drive, Single-In- Line types, but pin compatible with standard DIL relays.
The range features very high coil resistances, the 5 volt dry devices may be driven directly from 74HC or 74HCT logic without the need for additional drivers. Naturally, high resistance 12 and 24 volt coils are also available in this series.
74HC logic will drive up to 4mA at 5 volts which means that a nominal coil resistance of 1600 ohms is required to avoid running the IC at its maximum rating; 1600 ohms is the coil resistance of the single pole dry Series 98. A special model with an even higher coil resistance of 3000 ohms is also available, our type number
98-1-A-5/17D (the D suffix indicates an internal diode).
It is often possible to replace TTL ICs with their equivalent CMOS ones and replace standard DIL relays with Pickering Series 98, to obtain the benefits of CMOS without any circuit or PCB redesign.
The range like its SIL equivalent has an internal mu-metal screen to enable high packing density with negligible interaction between adjacent devices.
A useful tip
If there is a chance that you might want to use mercury wetted relays instead of dry relays at a later date, for example to increase switch ratings, lay out the PCB initially as though for the mercury wetted type with pins 1 and 14 uppermost. This allows uprating later without PCB changes. The mercury versions in the Series 98 have identical pin configurations to the dry types.