Will this circuit work?

[b_reagle]

Hello, I am trying to make a circuit for the truth table. I also am not sure if the diode "or" gate will work right. Thanks for the help.

 

[Mikebits]

The LS part has a very wimpy high output current IOH. You will never be able to drive that circuit. Why not just use an OR gate? Also keep in mind HC can drive LS parts ok but LS is not always able to drive HC, so you should stick to one logic family. Also why is R6 on your FET? I don't think you want to drive 50 ohms.

 

[b_reagle]

Thank you Mike,
I am trying to keep parts count to a minimum. I could use an OR gate but that is another chip. I forgot to change the chip families to both HC, as suggested by audioguru, as was R6 also suggested. I want a simple battery operated electric lock to make a motor forward and reverse only stoping when the lock is locked or unlocked. For now, U is a momentary push button. B and C are phototransistors. Maybe I will switch to Light Sensitive Resistors. No, I don't want to drive 50 ohms. I want to use as little as power as possible for the circuitry. All the power should be used only when motor is on, and very little when it is stopped. Thanks for the help.

 

[crutschow]

The 74HC00 will generate only about 2.0V or so across R7 which is only 100 ohms. R7 should probably be several k ohms.

How much voltage does Q3 require to turn on and carry the motor current?

 

[Roff]

I'm having trouble understanding your logic. Does B=1 mean light is present? Same for C=1? Does X=1 mean the motor is on?

 

[b_reagle]

B= 1 when light is not present. C=1 when light is present. X=1 when motor is on.

 

[Mikebits]

Is that part number for your FET correct? I could not find a data sheet for it.

 

[b_reagle]

Maybe this will help.

 

[b_reagle]

https://www.digchips.com/datasheets/parts/datasheet/232/IRF3711ZL.php

 

[Mikebits]

lol, I thought the Z was a 2. thanks

 

[on1aag]

Hi b reagle,

Replace the 74HC00 ****, D1, D3, R5 and R7 with a 74HC51.
I also have a problem with the base currents of the 2N2222's.

on1aag.

 

[Roff]

Why don't you do it like this?

 

[Mikebits]

Geez, I now have a bright red spot on my forehead from slapping myself. Good one Ron
And a spare gate to boot.

 

[on1aag]

I've got an excuse, it's 3 a.m.

on1aag.

 

[b_reagle]

Yes, I think that is it....The circuit is for an electric dead bolt than runs on batteries. Will all this work at 3 vdc?

 

[Roff]

I've got an excuse, it's 3 a.m.

on1aag.

No it ain't! It's 7PM!

 

[b_reagle]

Thank you very much!!! I knew something was just not right. Thanks again..

 

[b_reagle]

Is this right then??

 

[b_reagle]

Isn't the base current 4.9mA in the unnumbered Q's?

 

[Roff]

I would change R5 to 100 ohms.
If you don't need the extra gate, either connect the inputs to GND, or put it in parallel with the "output" gate to speed up MOSFET switching.
How much current does your relay require?

EDIT: I just saw your last post. R1 and R2 should be around 10k. If you don't get solid "0" levels at B and C, change R3 and R4 to 10k, and R1 and R2 to 100k.