555 Alterable-Precedence S-R Latch

Sset and Sreset should be push-button switches. S4a and S4b should be one double-pole single-throw (DPST) switch. If jumpers are to be used instead, setting of these switches should be a ganged-operation, both open or both close. When S4 (S4a and S4b) is open, precedence between SET (through TRIGGER/Sset) and RESET (through THREHOLD/Sreset) is defined by the specific 555 Timer device used (NE555 type or LM555 type). In NE555 set through TRIGGER has precedence over reset through THRESHOLD. In LM555 reset through THRESHOLD has precedence over set through TRIGGER. When S4 (S4a and S4b) is closed, precedence between SET (through TRIGGER/Sset) and RESET (through THREHOLD/Sreset) is altered by the setting of S3. When S3 is thrown upward (\) RESET (through THREHOLD/Sreset) has precedence over SET (through TRIGGER/Sset) regardless of the device type. When S3 is thrown downward/horizontal (─) SET (through TRIGGER/Sset) has precedence over RESET (through THREHOLD/Sreset) regardless of the device type. Currently only an LM555 model is available in Multisim.