Bistable Relay Driver

Although bistable relays boast significant advantages, their use appears limited to niche applications, probably because their practical use requires just a tad more attention to design details than classic relays. Those days may be over soon with the introduction of a special driver IC from Quasinil (what’s in a name?).It appears that most manufacturers of bistable relays have now succeeded in simplifying their products to the extent that a demagnetising circuit is no longer required, and a single switching signal does the job. In some cases it is possible to realise a driver circuit based on just a few discrete components. In this article we show the intricacies of bistable relay control, analyse a few simple circuits, mention the pros and cons and, finally, introduce the dedicated drivers type DRT5 and DRL5.