What does it do?
| The inverter subsystem, also known as a NOT gate, provides an output signal which is opposite to the input signal. When the input signal is high, the output signal is low, and vice versa. |
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How does it operate?
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Click on the circuit diagram to download a Livewire file of the circuit that you can investigate and add to your own circuit. |
The output from the inverter is shown in the truth table below, with 0 meaning “low” and 1 meaning “high”.
Truth table for an inverter
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American (ANSI) Symbol
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European (DIN) Symbol
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Possible applications
- Changing the operation of a sensor or a gate, so that something is turned on when, without the inverter, it would have been turned off
Making
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Pins of 4069B
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How part of the PCB might look |
The PCB shows the basic circuit. Several gates in the IC are not used in this simple design; they can be applied in other subsystems. Any unused input pins should be connected to 0V or Vs, to prevent damage by static electricity.
Build and test the unit that will provide the input signal before building the Inverter.
Use a Dual In Line (DIL) socket for the IC. Before inserting the IC, connect the power supply and use a voltmeter to check that:
- the voltage on pin 7 is low (0V);
- the voltage on pin 14 is high (the supply voltage);
- the voltage on pin 1 (the blue PCB track) goes high and low in response to the unit that provides the input signal.
Insert the IC the right way round.
Testing
Make sure that the signal going out (on the green PCB track) changes from high to low when the input signal (on the blue track) changes from low to high.
Fault finding
If there is a fault, check that:
- The voltage on pin 7 is low (0V)
- The voltage on pin 14 is high (the supply voltage)
Check the tracks and solder joints.
Alternatives
Web links
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