smoothing out voltage spikes and dips?

[ben7]

Re: smoothing out voltage spikes and dips?

Please disregard the diagram of REV 1, I drawn the connection wrong on the Ref adjust and Refout pin connection.
Here is the REV2 with the correction.
Hi Ben:
Yes,I hope the 5 Ohms-85 Ohms range is the correct info.
By the way how did you do the link like that with the word here and it links to the URL.

Highlight the word, then press the 'insert link' button (It looks like a globe with two chain links on it). Then just paste your link there, and click OK

[budm]

Re: smoothing out voltage spikes and dips?

I will try it, thanks!

[budm]

Re: smoothing out voltage spikes and dips?

Test: here

[ben7]

Re: smoothing out voltage spikes and dips?

Test: here

You did it!

Anyways, scampo, are you still there???

[scampo77]

Re: smoothing out voltage spikes and dips?

yes sorry i am back i was distracted by life for a moment, some jerkoffs broke into my house and set me back in life a bit, but i am back up and running now. and still very much am interested in this.

i have a few questions,

what is c2,c4,c5? they dont have the same symbol as the caps and they are labeled .1 100v

also, what is VR1? is it a o-500ohm trim pot? if so where do i set it at to start the prototype?

are you sure pin 4 goes right to ground like in the diagram?

[budm]

Re: smoothing out voltage spikes and dips?

They are caps, 0.1uf 50v or 100v (my schematic program library as them as 100V) polyester film.
VR1 is the 0-500 Ohms trimpot. You set it for LED10 to be on when full tank (sensor at full resistance)
Make sure to download REV2 drawing.

[scampo77]

Re: smoothing out voltage spikes and dips?

no luck, i have it built now and all that i can get to happen is at 85 ohms all the lights come on at once. anything under that they all go off.

i have 2.98v on pin 6,7

[budm]

Re: smoothing out voltage spikes and dips?

What do you get at pin5 when you vary that sensor, you shoukld see it changes. Does the trimpot has an affect?
Can I see the picture of what you built. This circuit coMES from app notes by TI with component's values adjusted to the sensor resistance. the REF Voltage is correct as calculated.

[scampo77]

Re: smoothing out voltage spikes and dips?

yes the voltage from the "float" varies the voltage from 0-3.3v

no, the trimpot makes no difference at all

i have enclosed a drawing of what i have done, it seems like there is too much ground going everywhere. on my trim pot i have 2 legs going to ground? i dont know if i am reading it wrong or if there is something i dont see

[budm]

Re: smoothing out voltage spikes and dips?

I can see that you have the resistors (1200, 1500 Ohms) hooked wrong, the 1200 Ohms resistor should be connected between pin 8 and 7/6. the pot connection is correct.
Please read the diagram carefully again.
I also note in the post 66 to make sure you use REV2.

[scampo77]

Re: smoothing out voltage spikes and dips?

sorry, the problem was in my horrible drawing, not in my prototype, i have changed the drawing to better represent my breadboard work.

[budm]

Re: smoothing out voltage spikes and dips?

OK, that is the way it should be connected, all LED will be on when input pin 5 sees about 3V (which is the 2.98V ref HI set point by the TRIM pot, when you adjust the pot, you will see that 2.98V will change).
At 1.5V input, LED will light half way up.
By the way, the display is set for DOT mode, pin 9 not connected, for bar mode, pin9 should be tied to VCC pin3 of the IC.
The circuit is based on this APP notes, so I know it should work, I just make the VREF adjustable.

[scampo77]

Re: smoothing out voltage spikes and dips?

ok , sorry i found the problem it is working wonderfully, including #10 being adjustable by vr1.

thank you very much for all this design work. im certain i can reproduce this on a circuitboard and put it into service

now, after 72 posts and months of work on this, can someone please answer my original question? LOL

how do i add (preferable adjustable while prototyping) a damping factor to the real time display of these bulbs? so it doesnt bounce from 2-10 everytime i hit a bump

[budm]

Re: smoothing out voltage spikes and dips?

OK, that is good, we got the basic circuits to work first, now we just need to get the damping circuits to the input pin. I will look into that next, you may be able to just add a small cap, try 10Uf first between pin5 and ground just to see if the damping is too much or too little, play with the cap value, then I can change the Charging/Discharging time later on with some diode and resistors, same Idea as ben7. I just want you to find the amount of damping you like first.
It can be simple circuit as attached, 100uf cap and 5k~10k pot.
By the way, what did you find wrong with the hook up?
I know that car has dual floats for damping in the tank.

[scampo77]

Re: smoothing out voltage spikes and dips?

good god!! have you ever seen that movie a beautiful mind? i have smoke coming out of my ears trying to follow your regular niceley laid out diagrams let alone this, im not familiar with this stuff enough to follow that one.

i am embarrased to say, but i had nothing to pin 4, i noticed it after you said hiref will be 3vdc. it seemed like it only came on at or above that so i thought what is low ref supposed to be? and then there was no wires hooked up to pin 4. i put it to ground and it took right off.

i am just cleaning it up now and i will try it out tmrw for a field test.

[budm]

Re: smoothing out voltage spikes and dips?

"im not familiar with this stuff enough to follow that one" Do you mean the damping circuits? It will be connected between the sensor wiper pin and pin 5 of the IC.

[scampo77]

Re: smoothing out voltage spikes and dips?

i tried just putting a cap between ground and pin 5 and nothing happened, im not familiar enough with electronics prototyping in general let alone that drawing you posted. i started to stare at it to make sense of it but i got a nose bleed so i quit looking at it.

[budm]

Re: smoothing out voltage spikes and dips?

It will have to be really BIG cap because the SENSOR is only 100 Ohms. It looks like you have to add my damping circuit, you can use fixed resistor (try 5K) instead of trim pot for now and 100uF cap.
It is good to have damping since there will be a cap at pin5 to help reduce noise from electrical system to interfere with the input signal due to long cable run from sensor to the board. It will take about 5 seconds for the cap to fully charge to the sensor sending voltage.

[scampo77]

Re: smoothing out voltage spikes and dips?

one other thing aside from the damping, it is the sensor "float1" right now on my breadboard i have a tri-leg trim pot i have pos on one side neg on the opposite side and i am taking pin voltage from the center leg. my real world sensor is only 2 wires, i can put one to ground or one to 10v but i cant keep it the same way that this is wired up here. i would be left with an unused wire.

and this IC is getting hot is it a good idea to glue a heatsink to it? not now, when it is all up and working.

[budm]

Re: smoothing out voltage spikes and dips?

You are correct, the sensor will have two leads, one lead will go to that 200 Ohm resistor bottom leg as shown in the diagram, the other leg of sensor will go to ground, when you move the sensor if it shows back ward (empty tank) show #10 LED, then just reverse the connection. Make sure you have that 200 Ohms resistor as shown in the circuit connected otherwise you will burn up the sensor.
Please pay attention to your sensor assembly, some of them will have one leg tied to the metal chassis which will be car ground, you should use you Ohm meter to see if any of the sensor leads is connected to the sensor chassis.