Using a bs2 for multiple shaft speed alarms

sport270

Quick question. I have several shaft speed alarms i need to rig up. They only need to trigger an alarm if they stop. All using a mag sensor against steel sprocket. Was wondering if a bs2 using freqin would be easiest option for a monitor of 8 shafts vs the circuit im using now based off of Lm2907....
Will trigger an led for each shaft as well as a buzzer if any are alarmed. Also have a 6 second timer at which the buzzer cuts off but led still shines if shaft is stopped

kwinn

A BS2 should work but seems like overkill for this. I used a 555 timer as a missing pulse detector for monitoring vacuum pumps. That would only require eight 555 timers each with an attached led and a diode.