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Help Needed With 4001

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Manihigh

New Member
Howdy all
I'm designing a digital lock system using xor gates. I have the lock working (8 digit binary code). Successful code activates solenoid and LED insuccessful activates audio oscillator and LED through Triac with a hidden cut-off switch. My problem arose when I decided to make the code easier to remember by using indicator LED's for I/O status. That is when a switch is OFF a green LED is lit and when ON a red LED is lit. I decided to accomplish this using a 4001 NOR gate. SO all switches in OFF position. Power up circuit = 8 GREEN LEDS. Without the REDS to indicate ON status everything works fine. ie when any switch is turned ON a high signal goes to a gate on the 4001.(currently only 4 switches and 1 4001 are being used if I work it out then I'll double that and have all 8 indicated). SO 4 GREEN LEDS ON. And checking switch outputs they all go off and on as they should according to the logical state of their individual gate. HOWEVER a problem arises when I try to wire in 4 RED LED's to come on when the GREEN go off( ie to indicate a HIGH signal). As long as I only send 1 high signal at a time all is cool. But when multiple signals come in high almost all current is drawn through the LED connected to gate 1 (or 3 if 1 is LOW). The inputs to the 4001 are from the 4 pin DIL switch. Is this a terribly confusing post???
If so I am very sorry but I am confused and cannot understand why an input to gate 2 for instance can give power to an LED coming off gate 1.

?!?!?!?!?
 

kinjalgp

Active Member
A circuit diagram will be able to explain it better. :)
 

Manihigh

New Member
Don't Worry

I tried to get a circuit diagram up but both my 'schematic drawing' progs use the wrong file type. However the problem seems to have rectified itself and all systems appear to be go! Thanks anyway.
 
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