开云体育

The information from Peter and David was instructive. I am working on a data logger which needs to start logging events that occur before a trigger condition to show what event caused the trigger.

Broadcast transmitters have multiple overload sensors to shut the transmitter down before damage can occur and lock on an indicator to show which section of the transmitter overloaded. The transmitter is then automatically recycled to turn it back on. If three overloads occur in rapid succession the reset is disabled and the transmitter stays off. The overload system then has to be manually cleared before the transmitter can be turned back on. The problem is that an indicator of an overloaded stage is often insufficient for troubleshooting if no visual damage is evident.

I am building an Arduino Uno based device which can monitor several transmitter parameters such as voltages and currents, and can timestamp each measurement and add a measurement identifier. Each measurement is then pushed into a queue (a FIFO buffer) in the Arduino RAM and the next measurement is taken. When an overload occurs (the trigger event) the entire queue is dumped into a connected laptop, the queue is cleared, and measurement resumes. That yields a picture of various transmitter parameters leading up to the overload - in effect a parameter measurement time machine.
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Dale H. Cook, Retired AM/FM/TV Chief Engineer, Roanoke/Lynchburg, VA