PLanning A Mod Please Check My Schematic

[Mark Linehan]

I have not done any electronics assembly in almost 3 decades. I did a little refresher reading, and I studied some designs. Can someone tell me if this is the proper wiring for a 5v mod with a kill switch/led and LDO 5v 3a regulator 510 atty/led design??

Mark Linehan

 

[asdaq]

Not quite, the LED needs to be parralel to the atty firing, say v-out and gnd, s2 should move to control and gnd, and that resistor after s2 should move to control and gnd too. Like this:

 

[Mark Linehan]

Do you have a photo of this? I'm a little confused.. it comes with old age.

If I move S2 to pin 3 and 4 won't that make the master power LED not function without both switches being pressed?? ..also why does the switch not work between Batt and Vin ?

 

[asdaq]

Oops missed your power-on LED. It needs it's resistor too but needs to go to the gnd not v-in. As for the fire switch, s2, you could have it inline after the master and going to v-in, but since you are using the control pin on the reg it needs to go there along with a resistor (a 3rd). This allows the reg to act as a mosfet and you can use an underrated switch (small). You can ignore the control pin too (have nothing there and no 3rd resistor) and use a 3A+ switch and just have it in front of v-in.

Sorry, I can't think of a pic that shows all the connections so clearly.

 

[Mark Linehan]

Oh wait, I get it. That's like a bread board design, right?

So if I keep it the way it is, but run the wire after the first led/resistor to Vin then add a third resistor after S2 before the control pin. Is that what you mean?

I apologize for my brick-headed-ness

 

[Mark Linehan]

How does this look now? I think I screwed up the attachments. Is the second correct??

 

[asdaq]

Oooh. That resistor from pin3-pin4 directly. Not in between. It enables the control circuit itself, not giving resistance to the switch.

 

[Mark Linehan]

LOL. I feel so dumb right now. You lost me again. I appreciate all your time and patience immensely though, thank you.

The resistor currently between 3 and 4 is for the LED, which is needed to avoid over heating the LED I thought?? If you are saying the resistor in line with the LED between the ground and control pin needs to be moved, I am at a loss at to where it is supposed to go or do I not need the 3rd resistor because there is already one between Vin and 3 - 4 ??? Oh man I feel like I have forgotten everything from electronics assembly classes. Allow me to both apologize again and thank you for the help again. I know you folks that are in the know on this forum must get really frustrated with us noobs at times. With me I think it is worse because I used to have fairly extensive knowledge, and things I used to know are cloudy and thereby confusing me all the more.

I have just enough knowledge to be dangerous still.

 

[Scubabatdan]

Let me try taking a stab at this, using your design with asdaqs input, I agree you should run the LED in parallel with the atty and the LED moved from inline with the switch to a parallel position, and move the main switch to the ground leg.

You are correct that each LED must have a resistor to limit the voltage so it does not burn out the LED. The resistor on legs 3 and 4 is necassary for the LDO to work. You should never place an LED inline with the power to a component, it should be parallel to the component so the component gets a direct path of power.

Here is a redesign of your circuit incorporating asdaqs circuit but without the PCB board.


Hope this helps
Dan

 

[asdaq]

Cheers Dan, the weather has been great and between modding errands and a bike ride I haven't had more than 5 mins at the computer at a time. And YES, like that.

Another way of reasoning it, each LED needs a resistor, and the regulator needs one to know the control pin is used in it's internal circuit. Mark, is that better?

 

[Mark Linehan]

Yes, that actually helped a lot, I was having trouble trying to read the bread board drawing version I guess. Now I understand, but I am curious about a couple of things. If I wanted to make my mod pretty for my sister by adding a 3 pin two color LED and a 555 chip to flash between the two positive connectors, would I need 2 resistors one for each positive leg of the LED or just the 1 resistor in line with the negative?

Thank you both so very much for the help, you have really helped me get a grasp on things I thought lost forever. ...but at least I can still read and draw a schematic at least. ...and I know I can still wield a mighty soldering iron. Most people I know hate using them, I actually enjoy it.

Right now I have an old SONY digital camera (like a 35mm style, very old and HUGE), a cordless phone, 2 cell phones, an answering machine, 2 power supplies and a scanner. I am going to seriously rape them of every interesting and usefull part they have.

I wonder how they make an automatic battery? They can't possibly be using pressure sensor switches or SIP/PUFF switches, they cost a fortune and the batteries would be very expensive I would think. Could they be using some sort of a pressure sensitive resistor of some kind? I mean it would have to be extremely sensitive in order to work properly. Well maybe not a pressure sensitive variable resistor but maybe cap instead??

 

[asdaq]

No worries at all Mark. One on the negative for that, but it would be nicer to use a fast or slow change LED, they are only 2 legs. However, the fast change can be a little nerve wracking, and the slow is like a lava lamp and if used in conjunction with the fire side of the circuit, you won't see all the pretty colors. Especially @5v.

With auto batts, its a sound sensor, picks up on rushing air and other things you wish it wouldn't.

 

[Mark Linehan]

That's what I thought .. must be some kind of mic or it would be expensive as all get out. Crap design concept using a standard sensitive mic though. Have there been many reports of misfirings issues with them? My guess would be a lot. I would love to make a REAL automatic battery with an actual SIP/PUFF switch of some sort. There are some barometric pressure sensors out there, not sure of the costs, but even those would be flakey with the weather.

OOOOH! IDEA ALERT! IDEA ALERT!!!

A tilt sensor or accelerometer(sic?) mounted on a thin and flexible wire or membrane or something that will move easily when someone applies suction to the mouthpiece?? Hmm.. Nahh.. It would misfire all the time when you moved it around.. Although! You could put in a 1 second delay so a bump wouldn't trigger it, but drawing on it for more than a second would fire it off. I'll have to think about this one.

I just looked at some of the SIP/PUFF switches out there, even just ugly head mounted things are HUNDREDS of dollars. That is insane. I wonder if I could find a schematic to build a SIP/PUFF switch. It wouldn't have to be that small, I could see making an automatic passthrough with a palm sized box, charger, 1 second motion delay.

Too many ideas popping through my head. LED read outs..

Juice tank with a soft flexible feed tube, a stepper motor on a momentary switch that has a cam shaft/egg shaped spindle that would rotate against the feed tube, and the egg shape would create and release pressure in the tube and move drops slowly up the tube.... hmmmm

Mark Linehan

 

[Mark Linehan]

Hey, what do you guys think about an auto ego batt where the switch is actually a human touch sensor IC attached to the metal cuff that loops around the battery where the current manual switch is located. I know it isn't really an auto battery, but it would eliminate a mechanical switch altogether and unless human skin touches the ring, it would not misfire. HUh? whaddayathink??