Definition
A digital electronic circuit with a single input that changes state each time it receives an input pulse. One pulse switches the output from low to high; the next pulse switches it back from high to low. The circuit holds whichever state it is in until the next pulse arrives.
Plain English
A small electronic switch that flips to the opposite position every time it gets a signal. Pulse once and it turns on; pulse again and it turns off. It stays where it is until the next pulse.
Context Anchor
Seen in aircraft electronics, avionics, and electrical system training when describing simple digital circuits or pulse-counting circuits.
Derivation
Toggle' comes from the back-and-forth action of a toggle switch. 'Flip-flop' describes the circuit's behavior of switching between two stable states. Together the name reflects what it does: each input pulse toggles the output, and the circuit flip-flops between on and off.
Why Pilots Care
A pilot normally does not operate a toggle flip-flop directly, but understanding the term helps when reading about avionics logic, electronic counters, and aircraft electrical troubleshooting.
Analogy
Like a push-button desk lamp where one press turns it on and the next press turns it off. The button doesn't care which state the lamp is in -- it just flips it to the other one.
Intuition Check
Do not confuse a toggle flip-flop with a physical toggle switch in the cockpit. Here, it means an electronic circuit that changes state when it receives a signal.
Example Sentence 1
The frequency counter in the avionics test bench uses toggle flip-flops to divide the input signal in half with each stage.
Example Sentence 2
Maintenance checked the toggle flip-flop output after applying a test pulse to confirm it switched cleanly.