Logic Test Probe
Created: Oct 09, 2014
No description available.
A Logic Test Probe is an analyzer device used to determine the logical states (logic 1 and 0) of a digital circuit. It indicates the logic state of the input or output node of any Transistor–transistor logic (TTL) logic circuit.
The power supply of the probe is the same with the power of the circuit that we want to analyse (same Vcc and same GND). To check the logic level of the test circuit, we must connect the "Test" wire of the probe to the desired node of the test circuit that we want to check. If the logic level is Low, the 7-segment will display a number "zero" (0) and only the green LED will be lighted. If the logic level is High, the 7-segment will display a number "one" (1) and only the red LED will be lighted. If the level is Impedance, the 7-segment will display nothing and no LED will be lighted.
When the "Test" wire is connected to the ground of the test circuit or the voltage is between 0V and 2V, the logic level is "Low". When the "Test" wire is not connected, has no voltage, or the voltage is between 2V and 3V, when the "Test" wire is connected to the positive supply of the circuit or when the voltage is between 3V and 5V, The logic level is "High".