Low Voltage Cut Out

[CapeCAD]

For those interested: I finally got a chance to test the resistor between Pin1 and gnd on an OKR 3 Amp converter, a value between 100k and 470k seemed to work best. At 500k and over the converter did not shut down when power was removed from pin 1.

*Edit: Tested with 3 Amp converter, 6 Amp or 10 Amp converters may need lower resistance (47k).

 

[bstedh]

For those interested: I finally got a chance to test the resistor between Pin1 and gnd on an OKR converter, a value between 100k and 470k seemed to work best. At 500k and over the converter did not shut down when power was removed from pin 1.

I am assuming you are using the zener modification to my drawing that you made? What ratting zener did you use?

 

[CapeCAD]

I am assuming you are using the zener modification to my drawing that you made? What ratting zener did you use?

I tested on the bench with 5.1V and 6.2V zener.

 

[Bdbodger]

Can you expain how this works to a noob . It looks like power is supplied to pin 1 when the switch is open and when the switch is closed power is somehow cut off to pin 1 even though it is still connected to ground by the resistor ?

 

[bstedh]

Can you expain how this works to a noob . It looks like power is supplied to pin 1 when the switch is open and when the switch is closed power is somehow cut off to pin 1 even though it is still connected to ground by the resistor ?

The OKR is normally in an on state. The resistor to ground turns it off by pulling the pin to -. + supplied by the switch turns it on. The zener will only conduct when the voltage across it is above its rating so the switch will do nothing if the batteries drop below this point.

The control pin circuit only uses a low current draw so you can use a low rated tactile switch instead of switching the main power load.

We are using a standard normally open switch.

 

[Bdbodger]

Makes sence . Have any of you though about selling pre assembled boards .

 

[bstedh]

Makes sence . Have any of you though about selling pre assembled boards .

thought about about it, but not too hard. =]

 

[Bdbodger]

Yes, a 6.6V zener would work and you can just add the zener and a ~680k resistor to your current setup to keep enable low at less than 6.6V

You don't happen to had a Digikey part number for the zener diode and resistors if you have them handy .

 

[skipdashu]

Just my 1.5 cents: Half way thru battery use, I swap the battery positions.

Now we'll need an alarm circuit for "Half way thru"! ;-)

 

[skipdashu]

What I have experienced is the battery closes to the Neg, always drains the most (lowest reading)

Me too. That's 'cause all them currents and raisins come out of the neg side. The other battery just used to push them out.



JUST kiddin' but serious about which battery seems to take the hit.

 

[breaktru]

Now we'll need an alarm circuit for "Half way thru"! ;-)

A wise ..., aren't ya

 

[asnider123]

Now we'll need an alarm circuit for "Half way thru"! ;-)

Actually, there are simple circuits that you can set to any voltage level and will indicate, with an LED, when you go below the threshold level. Think I saw it here on ECF somewhere ????? Set it to change led color when it reaches 7.4v

 

[skipdashu]

A wise ..., aren't ya

Jawohl, mein Kommandant

 

[skipdashu]

For those of you that might use Linux there's a schematic editor/drawer in the Ubuntu/Debian repositories called "gEDA Schematic Editor". I've only used it's 'drawing' mode for some very simple mod circuits so far. Here's an example screen:




Hmmm, try this for a bigger pic. This one is good 'nuff to give u a quick look at it

 

[skipdashu]

Actually, there are simple circuits that you can set to any voltage level and will indicate, with an LED, when you go below the threshold level. Think I saw it here on ECF somewhere ????? Set it to change led color when it reaches 7.4v

I'll take a look 'round but I was thinking more like 6.2~6.5v if I was doing the z-diode thing.

Oh wait, we were talking about half way houses weren't we... nvr mind.

 

[CraigHB]

For those of you that might use Linux there's a schematic editor/drawer in the Ubuntu/Debian repositories called "gEDA Schematic Editor". I've only used it's 'drawing' mode for some very simple mod circuits so far.

I'm not a Linux user, well not regularly, but from what I've read, gEDA competes with the best of them. It's a full PCB design suite. It also has a board editor that allows you to use your schematics directly in designing a PCB. Eagle is the suite I use for Windows and it's similar. Eagle has a big learning curve and can be downright frustrating at times, even after you're familiar with it. I'm sure gEDA is easier to use. One other really nice thing about gEDA is it has GerbV which allows you to view the plot files you send out for PCB designs. Eagle does not have that. There's a Windows version of GerbV so that's what I use.

 

[skipdashu]

I'm not a Linux user, well not regularly, but from what I've read, gEDA competes with the best of them. It's a full PCB design suite. It also has a board editor that allows you to use your schematics directly in designing a PCB. Eagle is the suite I use for Windows and it's similar. Eagle has a big learning curve and can be downright frustrating at times, even after you're familiar with it. I'm sure gEDA is easier to use. One other really nice thing about gEDA is it has GerbV which allows you to view the plot files you send out for PCB designs. Eagle does not have that. There's a Windows version of GerbV so that's what I use.

Wow, I had no idea. What u r doing is so far beyond how I'm using it... I installed it's device editor also but haven't spent any real time trying to figure that out.

Since it's stock libraries can draw caps, resistors, lines and some ICs that's about all I'm using it for at this point. Just to make pictures and get a visual. I have used it to send a schematic to my brother for 'how do I change this to..." questions and had thought if I had to I could do that here also even if it's just a screenshot.

Which reminds me that I need to go find that diagram where one of ya'll drew in the zener diode on the disable pin. I might get started on the V2 of the 'blue box' tonight.

 

[skipdashu]

Have I got all the parts in the right place with right values now?

S2 is a NO low amp momentary (mad vapes 8x8 tac)
S1 is SPST master power switch (the one spec'd in Dena pdf)
S3 is SPDT (with middle off) voltage selection for the display (the one spec'd in Dena pdf)
L1 is the atty
Z1 is either a 6.2v or 5.6v zener (online components)
R5 is a 200ohm trim pot (the one spec'd in Dena pdf)
U1 OKR-T/6 from mouser.com


Schematic

Thanx, Skip


PS: Red lines w/b 22AWG. Grey lines from B- to atty the same. All else is 26AWG.

 

[slimest]

Maybe you will like this board: eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices
Nothing to solder, som kind of a simple "balancer".

 

[slimest]

Maybe you will like this board: eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices
Nothing to solder, some kind of a simple "balancer".