Relay Logic Gates Table

Function 0R 1R 2R:001 010 011 100 101 110 111
0000 clear Q+,Q-
0001 AND N/A COM1-COM2 COM1-COM2
NO1-NO2
NO1-NO2
0010 AB' N/A NC2-NO1 NC2-NO NC-NO1
COM-NO1
0011 pass A N/A COM-NO COM1-NO NC1-NO COM1-NO COM1-NO
0100 BA' N/A NC1-NO NC-NO2
COM-NO2
0101 pass B N/A COM-NO NC2-COM2 COM2-NO2
0110 XOR N/A NC1-NC2 NC-NO
0111 OR N/A COM-NO COM-NO
1000 NOR N/A NC1-NC2 COM1-COM2
1001 XNOR N/A COM1-COM2
1010 not B N/A COM-NC COM-NC2 COM2-NC COM2-NC
COM2-NO
1011 B+A' N/A
1100 not A N/A COM-NC NC1-COM1 COM-NC1 COM1-NC COM1-NC
COM1-NO
1101 A+B' N/A
1110 NAND N/A COM-NC COM-NC
1111 mark Q+-Q- N/A

The 0R column indicates the connections required to make the logic gate in the given row, with no relays. Clear can be made by leaving Q+ and Q- disconnected, while mark can be made by connecting Q+ and Q-. No other gates can be made in this way, since there are no inputs.

The 1R column is for gates which can be made using a 1-input function. The listed contacts are where the output is read from (named Q+ and Q-). The single input comes from the coil.

The 2R columns (000-111) specify the dual-relay configuration needed to make the specified logic gate. 000 through 111 are the wiring connections (NC COM NO) that should be interconnected - for example 101 means connect each relay's NC together, connect their NO's together, but leave COM unconnected. The table data has the points at which the output may be read from (in the form of an open or closed circuit, as with 1R). There may be multiple configurations which make the same gate.

So far the dual-relay configuration for A+B' and B+A' has not been found.

Modified Sun Mar 25 08:48:47 2007 generated Sun Mar 25 08:56:33 2007
http://jeff.tk/relaylogic/rlogic.html