Relays

Relays switch high power currents using a low control current. This guarantees safe function of the loads connected (lighting, glow plug system etc.) and protects these and the on-board power supply from excess load or damage. Relays are essential particularly for high-current applications. Relays are ideal switches across the complete ambient temperature range of -40°C to 85°C with extremely low contact resistance in the closed state and high cut-off isolation when opened. Despite their compact design, modern automotive relays are able to switch on currents up to 300 A, and in individual cases are even able to route and switch off short-circuit currents of 500 A for several milliseconds. Thanks to the very low loss of power at the closed contact and the low electrical control power of around one Watt, automotive relays manage without additional heat sinks. In addition, electromechanical relays do not consume electrical energy when switched off.

Another advantage of relays for automotive applications is their insensitivity to interference voltages originating on the outside of the vehicle or even inside the vehicle itself: there are no problems with electromagnetic compatibility (EMC).

LEAB CDB Charge Current Distributors

The LEAB CDB charge current distributors were developed especially for automotive applications for the charging of two battery banks through generator, chargers or solar panels and replace diode bridges or relays. They are for universal use with 12V and 24V vehicles.

Thanks to the very latest in semiconductor technology, the charge current is distributed highly efficiently to the battery with the greatest requirements. The battery with the lowest voltage and thus the lowest charge is always charged first. Permanent voltage measurement at the inputs and outputs allows the current flow to be controlled in such a way that batteries of different sizes or different levels of discharge can be charged quickly and reliably. This leads to significantly better and more effective charging of (auxiliary) batteries particularly in short-haul traffic. In contrast to standard cut-off relays, it is impossible for starter and auxiliary batteries to mutually discharge one another even during charging operation. This in turn guarantees absolute start-up reliability.

LEAB Cut-off Relays

LEAB cut-off relays are electronically controlled high-power relays which were developed especially for use with several and large batteries. Switching and cut-off depend on voltage, so that the starter battery is always charged to a certain extent before the auxiliary battery is added to the circuit. If the battery voltage drops to below a certain value despite charging, LEAB cut-off relays disconnect automatically and reliably prevent the mutual discharge of the two batteries. Since the switching process takes place without vehicle signal cables, the relays can also be easily retrofitted to modern CAN-bus controlled vehicles.

Many LEAB cut-off relays offer additional options such as an emergency-start bridging in order to use the auxiliary battery for start-up if the starter battery is discharged.

Charging current distributor with cut-off relay
CDR electronic relays using MOSFET technology
Unidirectional
Unidirectional
Bidirectional
Bidirectional
Uni-/bidirectional, bistable
Uni-/bidirectional, bistable
Undervoltage Protection 2-stage battery monitor