Connection of the transistor in the discharge path betn 7 & 6 of 555

AI Thread Summary
In an automatic school bell circuit using a 555 timer, an NPN transistor (BC547) is connected to the timer's output pins to create a discharge path. A diode is used to ensure only one output activates the transistor at a time, allowing it to turn on and discharge the timer. The transistor is positioned between pin 7 and the junction of pins 6 and 2, with resistors in series with the emitter. There is uncertainty regarding whether the emitter should be connected to pin 7 instead of the collector, as this could affect the discharge path in astable mode. The user's practical implementation of the circuit is not functioning as expected, prompting a request for troubleshooting assistance.
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In an automatic school bell circuit, The outputs from 3 to 11 are connected to the base of an NPN (BC547) transistor through 1K resistance. A diode is connected in forward bias in each of those outputs so that only one output sends high pulse to the base of the transistor. When the high pulse is activating the transistor and makes it On it gives the discharging path of the 555 timer. The transistor is connected in between pin 7 and the shorted node of 6 & 2. There are two resistances in series with the emitter and the collector is connected directly to pin 7. Pin 7 is connected to 12V source through 10K resistance. I think the transistor connection will be reverse i.e. emitter will be connected to 7 instead of the collector. Otherwise the transistor will not make the discharge path when the 555 timer is in astable mode.Am I write? But practically my idea does not work. What is the problem? pls help.
 
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