Auction is for a "Latching Relay Board" which has a latching relay with two control coils to "Set" or "Reset" the two sets of output contacts. The latching relay will stay in its current state after power is removed from either control coil so it has a "memory" of the last state it was in.

More Available...

Use on model railway layouts to control power to tracks, particularly around turnout/points and can be controlled from the same signals as the turnout/point motor. The control coils are very sensitive and will operate either from a short pulse (eg. push-button or reed switch below track) or a steady voltage.

The control coils will NOT work with AC power source, only DC of about 12V. If you really want to control the relays from an AC power source, just put a diode in series with it to convert the AC to DC. Of course the output contacts will handle either AC or DC without a problem...

Many other uses eg. control of signalling lights, auto-reverse loops, back & forth lines etc.

Screw terminals provided for connections to both "Set" and "Reset" relay coils, as well as the 6 (DPDT) contacts.

Board is easily expandable to have more output contacts by simply plugging another board into the first one. The relay control signals are passed through to the second board and operate in the same way, now with extra output contacts...

PDF datasheet can be downloaded from http://www.jtelectronics.co.nz/QuickLink/LRL1.htm

Check out this link for "Simple Auto-reverse Controller" and on a bit further for using diodes to slow down... http://www.trainelectronics.com/Reverse_loop_dual_coil_relay/