LM311 Voltage Comparator

[shacklebolt]

EDIT:
Just seen Roff's post,,, did you really have all the 0V's 'floating'.???? doh.!

Yeah I really did! haha. I did have pin 4 connected to 0V but I didn't realize that the rectifier had to be attached to the battery 0V too.

In my defense, this is only the 2nd 'electronics project' I've worked on-- I did have 1 EE class but it was all theoretical (and maybe I didn't pay enough attention).

Eric and Roff, I am a mechanical engineering student and am pretty good at CAD (SolidWorks) so if either of you ever want some CAD work done, let me know!

Eric, as for the hysteresis, I didn't notice anything (maybe I wouldn't?) I'll buy a 470K tomorrow and try it out. Is there any way to shorten the time it takes the motor to turn off when I turn off the VAC?

Thanks Again!

Peter

 

[ericgibbs]

Y
Is there any way to shorten the time it takes the motor to turn off when I turn off the VAC?

Thanks Again!

Peter

hi,
Do you mean relay/motor switch OFF rate or stopping the motor.???

 

[Roff]

Use an SPDT relay, and connect the other relay contact to GND. This will short out the motor when the relay turns off, stopping the motor - maybe faster than you would like. If it is too fast, play around with some low-value resistors in series with the grounded contact.
EDIT: A reverse-biased 1N4001 diode across the motor should also work.

EDIT: These methods assume that you are switching the high side of the motor, i.e., the other motor lead is connected to ground.