[Updated with working schematic!!!]
I have a circuit which I tried to adapt from the 555 bistable configuration to have the 555 states controlled by input A and B; B always goes high before A.
I am trying to have the reset pin set high when B goes HIGH (1.5V) and since A would start HIGH, I expect that the output is HIGH.
When A finally goes HIGH (B will still be HIGH) the trigger pin voltage becomes 2V which is above 1/3Vcc, I expect the output to go LOW since the trigger pin has been pulled HIGHer than 1/3Vcc.
I tried the circuit below and an LED hooked to the output stays on through out, it doesn't change even if I try to pull the trigger pin to a significantly high voltage.
The overall truth table I am trying to get out of the 555 is included below:
| A | B | Output| | - | - | ----- | | 0 | 0 | 0 | | 0 | 1 | 1 | | 1 | 0 | 0 | | 1 | 1 | 0 |
Can someone please tell me what is wrong with this configuration and/or suggest a workaround using the 555?
Hope it helps:) (sorry for the inconsistency in the circuits.)