need help! :0 4011 NAND gate

[atollp]

Hello there,

I have a 4011 NAND gate IC, just using one gate and I tied all other inputs to ground. I have the first gate's inputs tied together to form a NOR gate. I connected that input to a separate circuit with a separate power supply. I connected it to the positive side of the separate circuits battery, thinking that the input would see a 'high' level and since the output is inverted it would be low. However whenever I move or adjust wires (the circuit is on a breadboard) the output from gate 1 goes on and off. I'm wondering:

Is this even appropriate? To use a separate power supply and all for the input to sense from?

Is the breadboard the problem?

Should I use a 4093?

Any feedback is greatly appreciated.

 

[duke37]

I do not follow your description. Sketch out the circuit to show what you did.

You do not say whether the two power supplies have a common reference which will be needed.

 

[Harald Kapp]

1) If you tie the inputs of a NAND together, you form not a NOR but an inverter.
2) you need to connect the GNDs of both power supplies (the "common reference" mentioned by duke). If the separate power supply you mention is not connected to the supply of the IC, the input will be floating regardless of the voltage of the separate supply. A floating input on a CMOS gate is bad for the IC and leads to unpredictable results.

Harald

 

[atollp]

I think it is attached here, sorry for all the confusion haha

 

[Harald Kapp]

It is all as stated in the first two responses to your post.

Harald

 

[atollp]

hahaha after all that.

Ok well, I connected the negative sides together and it works. Thanks man for the adive and patience.

hehe