EverCool Variable Voltage Mod

[SurvivorMcGyver]

Per TI, the 100k resistor will not pull the inhibit pin down enough to work.

I saw some N/C switches earlier, but they are SMT. Has anyone tried them, or should I just go with a FET or transistor and an NO switch?

Did you ask if a 30K or perhaps a 56K might work?

If you are talking about these SMT switches -- They work flawlessly

 

[MrByte]

Did you ask if a 30K or perhaps a 56K might work?

If you are talking about these SMT switches -- They work flawlessly

Those are the switches. I was concerned that they would melt easily since they are SMT and I figure the average Joe isn't really setup to do SMT work in the garage/workshop.

The TI question/answer was thus:
Me:

"I'm sorry if this is a dumb question; I'm more a hobbyist than an engineer.

In my application, I'd like to use the inhibit pin to turn the device on/off, however, I'm limited to using a N/O tactile contact switch. If I tie the inhibit pin to ground via a 100K ohm resistor, then use my switch to supply positive voltage of up to 8.4V to bring the pin high, will this exceed the maximum voltage level for the inhibit pin? The application is battery powered so I can drop to 3.7v max if needed."

TI's exact response was:

"The PTR series inhibit pin must be controlled by an open drain FET. It cannot be pulled up to any voltage. The 100K resistor will no disable the PTR series. The PTR series inhibit pin must be pulled to ground to disable it or <0.6V."

I honestly barely know enough to follow simple schematics. The thought of changing the value of the resistor never occurred to me. Given a max voltage of 8.4 for 2 fully charged Li Ion's @ (claimed) 600mAh each, but more likely 250mAh after a bit of use, what would be the lowest resistor value I could get away with? I'm assuming the reason for a resistor there is to keep that line to ground for pin 1 from becoming a dead short when the fire button is used.

I can grab some different values off RatShack when I go there to fill out the rest of the stuff I'll need, or I can grab some off DigiKey, since it appears I will need some items RS doesn't carry. (Trimmers, mostly.)

My only "electronic" achievement was figuring out how to use a power diode (ie: BIG diode) to back-feed my running lights on our Triumph Spitfire after I changed it's headlight switch. The normal switch is $150, a switch that is only slightly different electrically and fits perfectly is way less, or commonly available on eBay. I used the diode to feed the running lights from the headlight line but to keep from feeding the headlights from the running lights, when the headlights are off.

Tried to change the switch's wiring, but it's a Lucas...and if you've ever had a British car/bike...you know all about Sir Joe Lucas, Lord of Unlight, Patron Saint of the Stranded, High Prince of Darkness. ;-)

So, in my long-winded fashion ;-) I'm saying I'll probably order up some of the SMT NC tactiles, but I might give the resistor@lower value a try as well.

 

[MidnighToker]

K, I poked through a bunch of this thread and could not find the answer...

WHERE the hell did you guys get that PCB with just the straight lines connected (like a breadboard)?!?! When I first scanned through the thread, I just grabbed the diagrams, schematics, etc.

I've been messing with this for about a week now and going nuts just trying to make due with what I found at RatShack, but it was not pretty.

The "Mini Pre cut Interconnect Circuit Board"? Are you friggin kidding me?! That's one of the first places that I looked, but there are no pics of the backside so I just assumed it was just prepunched.

Yeah...pretty much, but the copper strips on the back run from top to bottom?

Mini Pre cut Interconnect Circuit Board

Kinda says it

Here are the parts for the PCB

Just got my boards in from madvape as requested and they are JUST as I thought they were...simple pre-punched. I thought that they had the copper strips as pictured?!?!

 

[asdaq]

In the mini you can see the interconnect running horizontally in this pic:

There's green covering it but it is there.

 

[MidnighToker]

In the mini you can see the interconnect running horizontally in this pic:

There's green covering it but it is there.

K...now I feel like an .... Look at it under the glass and saw it. Thanks.

 

[MrByte]

Is there a DigiKey/Jameco/name_your_distributor_here shopping list? I think I've managed to figure out the trimmer and caps, etc, but some independent confirmation would be cool.

 

[WillyB]

Those are the switches. I was concerned that they would melt easily since they are SMT and I figure the average Joe isn't really setup to do SMT work in the garage/workshop.

TI's exact response was:

"The PTR series inhibit pin must be controlled by an open drain FET. It cannot be pulled up to any voltage. The 100K resistor will no disable the PTR series. The PTR series inhibit pin must be pulled to ground to disable it or <0.6V."

I honestly barely know enough to follow simple schematics. The thought of changing the value of the resistor never occurred to me. Given a max voltage of 8.4 for 2 fully charged Li Ion's @ (claimed) 600mAh each, but more likely 250mAh after a bit of use, what would be the lowest resistor value I could get away with? I'm assuming the reason for a resistor there is to keep that line to ground for pin 1 from becoming a dead short when the fire button is used.

So basically TI just repeated what the datasheet says.

Note that mAh is basically the capacity of the cells, a predictor of runtimes. It has nothing to with any other calculations.

It also appears that Java linked to an incorrect example that just muddled the issue. CapeCad's wiring diagram can only be used by a regulator with a control pin that is normally off when open, that does not apply to any TI inhibit pins I've seen. In his first Murata mod he said he used the Murata Power Solutions OKR-T/3-W12E-C DC/DC converter.

Note the 'E' and how the 'E' version differs.

From the datasheet.

Forced On/Off Control

Blank = Standard on/off, open pin = ON

E = Forced enable, open pin = OFF

In other words the 'E' version functions the same way as MV's Fairchild 4pin w/control pin. Not like the TI's. And the resistor in this case will will keep the reg off when no voltage is supplied and limit volts/current.

Compare this from the datasheet to CapeCad's schematic.

[“E” version]

Positive Logic ON = +2 V. to +Vin max.,
100KΩ pulldown to ground
OFF = open pin or –0.3 to +0.4 V. max.
Current 1 mA max.

In other words no matter what resistor you try with the TI, simply running current to the inhibit pin with a NO switch like CapeCad did ain't gonna work.

Don't you just love a challenge?

 

[Java_Az]

It also appears that Java linked to an incorrect example that just muddled the issue.

How is it incorrect. I never said it would work. I said take a look at it. Unless your saying CapeCads circuit is incorrect Then i don't know i didn't completely check it. Someone was trying to solve a problem so i linked info i though was helpful. I guess i will keep my info and links to myself since i just muddle thread up.
Peace

 

[MrByte]

Don't you just love a challenge?

Yup. My challenge now is to either solder in the surface mounted NC tactiles, or use the Muratas I've got in the shopping cart at Digi-Key. The schematic posted currently for Coolgate doesn't call out the "E" chip.

So are you saying an NC switch will not work with the TI chip? What I got from the data sheet was that grounding the inhibit switch will disable the chip. I would think that breaking the ground would activate it.

Just because I'm not knowledgeable in electronic circuits doesn't mean I'm a complete idiot. I thought the mAh not only indicated the "size of the tank" as we say in RC models, it would also indicate the possible amperage delivery, similar to "Cranking Amps" in a car battery.

 

[MrByte]

How is it incorrect. I never said it would work. I said take a look at it. Unless your saying CapeCads circuit is incorrect Then i don't know i didn't completely check it. Someone was trying to solve a problem so i linked info i though was helpful. I guess i will keep my info and links to myself since i just muddle thread up.
Peace

Java, I took it as "Look at this, it might work."

 

[Java_Az]

Java, I took it as "Look at this, it might work."

Sorry it didnt pan out MrByte thought there was a good chance it would. Glad you took it how i meant it. Just having one of those days so don't mind me.

 

[rannox]

Sent my sample request for the Lineage chip (NSR010). They sent me a PDF of a newer chip, supposedly better and cheaper, or so they say http://www.lineagepower.com/oem/pdf/NQR010A0X.pdf

 

[WillyB]

How is it incorrect. I never said it would work. I said take a look at it. Unless your saying CapeCads circuit is incorrect Then i don't know i didn't completely check it. Someone was trying to solve a problem so i linked info i though was helpful. I guess i will keep my info and links to myself since i just muddle thread up.
Peace

My mistake I guess. I assumed we were talking about using the TI Evercool and how to use it's inhibit pin with a switch. And yes CapeCad's circuit is incorrect for the Evercool. And that circuit then launched into the useless 'which resistor' discussion.

I'll just let you handle the rest of the thread.

 

[roadrash]

What I got from the data sheet was that grounding the inhibit switch will disable the chip. I would think that breaking the ground would activate it.
QUOTE]

That is correct.

 

[CapeCAD]

I do not have a ptr08100 to try, but has anyone tried a resistor divider to use a NO switch?

View attachment NOSwitch.pdf

 

[SurvivorMcGyver]

So basically TI just repeated what the datasheet says.

Note that mAh is basically the capacity of the cells, a predictor of runtimes. It has nothing to with any other calculations.

It also appears that Java linked to an incorrect example that just muddled the issue. CapeCad's wiring diagram can only be used by a regulator with a control pin that is normally off when open, that does not apply to any TI inhibit pins I've seen. In his first Murata mod he said he used the Murata Power Solutions OKR-T/3-W12E-C DC/DC converter.

Note the 'E' and how the 'E' version differs.

From the datasheet.


In other words the 'E' version functions the same way as MV's Fairchild 4pin w/control pin. Not like the TI's. And the resistor in this case will will keep the reg off when no voltage is supplied and limit volts/current.

Compare this from the datasheet to CapeCad's schematic.



In other words no matter what resistor you try with the TI, simply running current to the inhibit pin with a NO switch like CapeCad did ain't gonna work.

Don't you just love a challenge?

Oh how I love challenges.......

Sorry to .... in but I believe CAPEcads (originally My) solution works for both chips "E" or not -- mine are "not" and it has worked perfectly -- so I passed it along.

The Ti response is, IMHO, political - to support the corporate directive – “Don’t contradict what we publish”. Murata does NOT publish this solution but it works and works flawlessly with THEIR chip. I, like CC, don’t have the 8100 to test but if I did, I would -- just to prove a point – that being – the spec sheet does NOT tell all , electronics are amazing, and you CAN teach an old dog new tricks even if you have to fool it to do so like Nuck has done. One never knows until you try it. Has anyone?

If not, I will imeadiately volunteer for the task and order the chip.

OK – continue on, I’m done (and still think it is possible....) Hmmm look at that post above....


Open minds are Gods gift to the Heavens

 

[givesuhe11]

Open minds are Gods gift to the Heavens

Amen...

You do mean "Normally" Open Minds... right?

 

[MrByte]

I do not have a ptr08100 to try, but has anyone tried a resistor divider to use a NO switch?

View attachment 30628

What's that symbol that has the arrow pointing up/right?

 

[Java_Az]

Ok since i started this stir and after reading McGyvers words of wisdom i went ahead and tested with a 10k resistor ( all i could find laying around) A 10k resistor will put the chip to sleep. So i went ahead and wired it up the same as in CapeCads schematic. It does work for me on this TI ptn08060w chip that way with a NO switch. Vapes nicely also. I will have to go to radio shack to get some 100k threw-holes tomorrow and test it with one of those. I could swear i have some 47k around here somewhere i will look and see if i can give those results tonight. Keep in mind this the 6 amp version of the chip and i have not looked at the data sheet for info on the inhibit pin. Also this is my test chip i didn't care if i fried it and i don't know the long term effects of a 10K resistor on it.

Edit#1
Direct switch amp draw 12volt, input side of regulator .81 amps
Inhibit pin amp draw 12 volt, input side .84 amps
Does draw about 30 extra milliamps wired up using the inhibit pin

Edit#2
Found one more 10k resistor and ran the 2 in series 20K is not enough to put it to sleep. So i guess it was luck of the draw with the first 10k.
Please note that even though this worked for me, I dont not endorse or advise it`s use in any way shape or form. Use at your own Risk
My advise wanted or not would be to go with Big blues original plans and use a big old fat amp switch, The chicks dig them

 

[MrByte]

Ok since i started this stir and after reading McGyvers words of wisdom i went ahead and tested with a 10k resistor ( all i could find laying around) A 10k resistor will put the chip to sleep. So i went ahead and wired it up the same as in CapeCads schematic. It does work for me on this TI ptn08060w chip that way with a NO switch. Vapes nicely also. I will have to go to radio shack to get some 100k threw-holes tomorrow and test it with one of those. I could swear i have some 47k around here somewhere i will look and see if i can give those results tonight. Keep in mind this the 6 amp version of the chip and i have not looked at the data sheet for info on the inhibit pin. Also this is my test chip i didn't care if i fried it and i don't know the long term effects of a 10K resistor on it.

Edit#1
Direct switch amp draw 12volt, input side of regulator .81 amps
Inhibit pin amp draw 12 volt, input side .84 amps
Does draw about 30 extra milliamps wired up using the inhibit pin

Edit#2
Found one more 10k resistor and ran the 2 in series 20K is not enough to put it to sleep. So i guess it was luck of the draw with the first 10k.
Please note that even though this worked for me, I dont not endorse or advise it`s use in any way shape or form. Use at your own Risk
My advise wanted or not would be to go with Big blues original plans and use a big old fat amp switch, The chicks dig them

Thank you for the test, Java.