digital-logiclogic-gates
i am trying to create a digital logic trainer. to provide inputs through switches and outputs through LEDs, however when i connect the logic gates to the switches they don't work the way they are supposed to do. i am guessing that the gates need high or low not on or off.
can you guys explain or direct me to a link to a switch that can provide high when activated and low otherwise.
for example this is the scehmatics :
simulate this circuit – Schematic created using CircuitLab
thank you!
This question is quite open ended but ECC was fun to explain to my other friends back in college so where we go. Firstly, a correction: This produces a 12bit number, not a 13bit one. Data bits 0-7 and parity bits 0-3. Your schematic is wrong and would never work.
"If I feed inputs 3 5 7 9 11 into an XOR gate, will it indeed give me the result of the parity bit 1 (P1)?" Yes. That xor gate must have 5 inputs but yes. Also you shouldn't feed the outputs 3,5,7,9,11 of your circuit to the input so please refer to the equation as P1= D0 XOR D1 XOR D3 XOR D4 XOR D6.
If you don't have an XOR gate with 5 inputs then you'll need to ask a new question telling us what you actually have to work with.
This because of internal circuit structure , something like this picture.(this is not Gate)
Logic IC have 2 type :
1-CMOS
2-TTL
You're choose is 74XX.Most of them is TTL.
In some CMOS IC this Undefined input is fixed the only input declare "1" that is connected to 5v or IC Voltage . Choose similar CMOS.
but you're "0" logic doesn't need 1k resistor it can be direct connected to ground.
Best Answer
First of all, your digital logic IC needs power as well, of course. Second, your LED needs a resistor - it's probably blown up already. The switch should be done more like this:
simulate this circuit – Schematic created using CircuitLab
If you want to keep the switch in the way it is, where when the switch is "on" the input to the gate is "HIGH", then you can do it like this, and still have a valid signal when the switch is not pressed:
simulate this circuit
In the second way, the LED will be always ON until the switch is pushed down, and while the switch is down, the LED will be OFF.