I need a voltage comparator CI

M

moonstreat

New Member

• Mar 27, 2010

• #1

hello, I'm up a circuit, which is as follows:

**broken link removed**

- I have this engine running in one direction of rotation, and LED lights;

- But when I change the direction of rotation, the polarization change, and the LED no longer turns on!

I would like information about a CI that fassa comparison of + / - signs, so I can have the LED always lit ..

solution would be to use the 74LS32 (OR gate), but its supply is 5V ..

thank you for your help.

 

Last edited: Mar 27, 2010

W

Wade Hassler

Member

• Mar 27, 2010

• #2

Here's one way

 

M

moonstreat

New Member

• Mar 27, 2010

• #3

Thank you my friend!

I already test! D;

 

M

moonstreat

New Member

• Mar 27, 2010

• #4

this circuit does not work .. because if I change the polarization of the entry .. the LED does not light! so it is lit in this way .. the reverse he is off!

 

G

Gobbledok

Active Member

• Mar 27, 2010

• #5

That way will work. The diodes are set up like a bridge rectifier so it doesn't matter which way the current is flowing, the diodes will correct it to run the LED. If the LED isn't lit then it is probably a construction fault.


Edit: What voltage is your motor? If it's really low then that will stop the LED coming on.

 

Last edited: Mar 27, 2010

Vizier87

Active Member

• Mar 27, 2010

• #6

you'd save diodes if you used two LEDs with complementary polarity to the output pins, rather than using four diodes.

 

W

Wade Hassler

Member

• Mar 27, 2010

• #7

Here's a deluxe version
The LED now tells you that:
+12 supply is present
+5 supply present
Motor is on and drawing at least 1 amp
(adjust Rsense and R2/R3 ratio for specific current)

 

M

moonstreat

New Member

• Mar 28, 2010

• #8

I realized these mounts!

**broken link removed**

only the first worked! in the image below, the LED is not lit! = \

 

Last edited: Mar 28, 2010

Vizier87

Active Member

• Mar 28, 2010

• #9

they're the same man.

 

M

moonstreat

New Member

• Mar 28, 2010

• #10

Vizier87 said:

they're the same man.

Click to expand...

polarizations are exchanged!

I tried .. did not work!

 

Vizier87

Active Member

• Mar 28, 2010

• #11

the diode network makes sure the current goes from A-K. it doesn't make sense just because you switched the polarity, since the diode network is a rectifier by configuration. must be something else which is the problem.

 

M

moonstreat

New Member

• Mar 28, 2010

• #12

I'll try again .. then say something!

have you called this circuit pa know if it works?

 

Roff

Well-Known Member

• Mar 28, 2010

• #13

moonstreat said:

I realized these mounts!

**broken link removed**

only the first worked! in the image below, the LED is not lit! = \

Click to expand...

The two circuits are identical. One is just upside down from the other.

 

Vizier87

Active Member

• Mar 29, 2010

• #14

exactly. That's what I've been trying to tell.

 

M

moonstreat

New Member

• Mar 29, 2010

• #15

Hallelujah!

staff, has already managed to connect the circuit ..

Today I called again and was working well!

I must have fooled me to some link!

Thank you for your attention and patience! = P

 

Vizier87

Active Member

• Mar 30, 2010

• #16

phew. ok good for you dude.