Have you tried using the other comparator in the chip?

 

Have you tried using the other comparator in the chip?

Well, I have bought 5 of these and tested all of it with same circuit. Not working

 

Try connecting a 4.7K resistor from the output (pin 12) to the +9 volts.

 

I see no ground connection on pin #6, no connection of any kind at all.And no pull-up resistor on the output. If the circuit is not completed it will not work.

 

Try connecting a 4.7K resistor from the output (pin 12) to the +9 volts.

Is the +9V you are refering pin 11 or do i have to hook up another new 9V battery?

 

You have 3 wires going into the same hole in row 16 of your breadboard. That is bad practice and is likely to distort the contacts in the breadboard and result in a poor connection.

 

Yes to pin 11. A 4.7K resistor from pin 11 to pin 12.

 

Here is my new connection. No square wave on the output. Strange, isnt it? Have anyone of you tried this IC on breadboard?

 

Put the jumper back in from pin 3 to ground.

 

Put the jumper back in from pin 3 to ground.

Done. The output is 1.2V this time. No square pulse

 

Reinstall the .01uf cap.

 

Are the chips from a reliable distributor?

 

hi,
I cannot get it to run in LTspice using the posted component values.
E
View attachment 255652

Yup, same result as LT spice. I am planning to modify the LT spice so that the LM 319 can produce high frequency square wave. Can you share your LT spice model and library files involved? Thank you

 

hi,
I cannot get it to run in LTspice using the posted component values.
E
View attachment 255652

It is pretty weird right? It should work haha

 

hi @MrsssSu
Where did you get the circuit from.??
Link, please.
E

 

hi @MrsssSu
Where did you get the circuit from.??
Link, please.
E

From this site.

 

I see why this is not working, try this modification:

In the original circuit with the pullup resistor added and pin 3 connected to ground the reference voltage for the + input goes to ground when the output goes LOW. At this point the capacitor cannot discharge low enough to switch the output back HIGH.
Added R3 to set the reference and R1 now provides hysteresis.

 

Show a drawing of how your two batteries are connected to each other and to the circuit.

 

hi @sghioto
Looking OK.
E

 

Eric,
I tested the circuit using a LM393 with a single 9 volt supply. Why did you choose R2 at 25K rather 330K?