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.
?!?!?!?!?
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.
?!?!?!?!?