Will this circuit work? - Electronic Circuits Projects Diagrams Free

b_reagle · 5th August 2008, 10:20 PM

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 · 6th August 2008, 12:09 AM

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 · 6th August 2008, 04:29 PM

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 · 6th August 2008, 05:22 PM

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 · 7th August 2008, 01:24 AM

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 · 7th August 2008, 01:31 AM

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

Mikebits · 7th August 2008, 01:43 AM

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

b_reagle · 7th August 2008, 01:46 AM

Maybe this will help.

b_reagle · 7th August 2008, 01:48 AM

http://www.digchips.com/datasheets/p.../IRF3711ZL.php

Mikebits · 7th August 2008, 01:50 AM

lol, I thought the Z was a 2.

thanks

on1aag · 7th August 2008, 01:51 AM

Hi b reagle,

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

on1aag.

Roff · 7th August 2008, 01:57 AM

Why don't you do it like this?

Mikebits · 7th August 2008, 02:04 AM

Geez, I now have a bright red spot on my forehead from slapping myself. Good one Ron

And a spare gate to boot.

on1aag · 7th August 2008, 02:07 AM

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

on1aag.

b_reagle · 7th August 2008, 02:10 AM

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?

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6th August 2008, 12:09 AM	(permalink)
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. __________________ Pay it forward.

6th August 2008, 05:22 PM	(permalink)
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? __________________ Carl

7th August 2008, 01:24 AM	(permalink)
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? __________________ Ron

7th August 2008, 01:31 AM	(permalink)
b_reagle	B= 1 when light is not present. C=1 when light is present. X=1 when motor is on.

7th August 2008, 01:43 AM	(permalink)
Mikebits	Is that part number for your FET correct? I could not find a data sheet for it. __________________ Pay it forward.

7th August 2008, 01:48 AM	(permalink)
b_reagle	http://www.digchips.com/datasheets/p.../IRF3711ZL.php

7th August 2008, 01:50 AM	(permalink)
Mikebits	lol, I thought the Z was a 2. thanks __________________ Pay it forward.

7th August 2008, 01:51 AM	(permalink)
on1aag	Hi b reagle, Replace the 74HC00 shit, D1, D3, R5 and R7 with a 74HC51. I also have a problem with the base currents of the 2N2222's. on1aag. Last edited by on1aag; 7th August 2008 at 01:58 AM.

7th August 2008, 02:04 AM	(permalink)
Mikebits	Geez, I now have a bright red spot on my forehead from slapping myself. Good one Ron And a spare gate to boot. __________________ Pay it forward. Last edited by Mikebits; 7th August 2008 at 02:06 AM.

7th August 2008, 02:07 AM	(permalink)
on1aag	I've got an excuse, it's 3 a.m. on1aag.

7th August 2008, 02:10 AM	(permalink)
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?