The circuit uses two cross coupled nand gates which form an s-r latch, a spdt (single pole double throw) switch, two pull up resistors the resistor generates a logic ‘one’ for the gates, switch pulls one of the inputs to ground. Switch circuit of nand gate. Gates and logic: from switches to transistors, logic gates and logic circuits iclicker lab0 was a) too easy b) too hard c) just right d) have not done lab yet goals for today from switches to logic gates to logic circuits logic gates • from switches • there are seven basic logic gates: and, or, not, nand (not and), nor (not or.