The AND and NOR Gates
Just as the OR gate and NAND gates are related, so to are the AND gate and NOR gate, and as such both are featured on the one page.
The AND Gate It might appear to be a simple matter to just NOT the output of the NAND gate and get an AND gate. But, if you reverse the internal shaft mechanism of the OR gate, interchanging the position the fixed and rotating beam, then the OR gate becomes an AND gate! What's more it means that a NAND gate can now be made with fewer parts than previously (one NOT+AND,versus two NOTs+OR).
The LDRAW/MLCAD model is available for downloading.
Using the simplified NOT gate as discussed on the NOT gate page it has been possible to simplfy, by quite a considerable amount the AND gate. The following four photos show the new AND gate in its four different states. And if your're keen to see it in action there is also a video (758KB) available to download.
The NOR gate Like the NAND gate, the NOR gate can be made simple by NOTing the OR gate output. However, just as the NAND gate can also be made by NOTing the inputs of the OR gate, if the inputs of the AND gate are NOTd then you get a NOR gate. Again this can be achieved by using the NOT gates or by adding an addtional cog into the gear train.
The MLCAD model is available for downloading.
Using the simplified NOT gate as discussed on the NOT gate page it has been possible to simplfy, by quite a considerable amount the NOR gate. The following four photos show the new NOR gate in its four different states. And if your're keen to see it in action there is also a video (597KB) available to download.