5 volt Diagram Box Mod - WIll this Work??

[j0ker]

In my diagram there is no LED, lol I think that's what you meant

So this is what will work then correct??

Yes Dgreen, as long as the pin to the far left on the reg is pin 1. It's important that pin 1 is the input. The circuit won't work and could also fry the battery if you connect your battery input to pin 3.

 

[j0ker]

I am still just learning, so someone PLEASE correct me if I am wrong, but I believe that the LED should go in between the 3rd and 4th pins, with the 470 ohm resistor.

The circuit that we are discussing here is using the reg without the control lead. This reg only has 3 leads, not 4. It's wired similar to this circuit but let's not get into it in this thread. I feel it with only confuse the matter.

Adding an LED to this diagram would only require you to add a 470 ohm resistor from the output of the reg, to the positive side of LED and the other side of the LED (negative side) to ground.

 

[5cardstud]

Oh I'm sorry the second post had a picture of a 4 pin diagram I thought was involved also.

 

[kemuri]

It's an optional part that cleans any spikes or ripple generated by the regulator, it'll work fine without it but is recommended by the manufacturer.

hoog

Hi Hoog, want to make sure--recommended for all 3 types of 5v 3A regs that you carry? So I wire in the capacitor right after the Vout of your LDO, and from the capacitor to the center of the atty right? I'm assuming with the capacitor legs it doesn't matter which is Vin and Vo, both legs are interchangeable?

One last question*--if I were to reduce from 5v to around 4.2 to 4.5v, the path would be LDO, capacitor, resistor (or diode), then center of atty?

*actually the last question is do you have a resistor or diode which would effect the approx. half volt reduction? Good thing I still have some space left in your 3A box to play around in.

Sorry OP for straying a bit from your topic. As mentioned, poke around the madvapes forum and the madvapes site. There are illustrated DIY's there.

 

[j0ker]

Here's OP's orginal design with LED rudely implemented into diagram.

Oh I'm sorry the second post had a picture of a 4 pin diagram I thought was involved also.

Sorry 5cardstud and jace, see I told you it would confuse, it confused me! Second post was using the reg with control lead. I forgot. There's going to be a little difference in the wiring for the controlled reg. I can draw up a diagram for it as well but we might want a new thread so not to confuse the 2 different circuits.

 

[dgreen]

Thanks for the help everyone. What is the 4 pin control lead for?? What does it do. I just thought it would be easier to get a 3 pin regulator from radio shack and not have to use the whole circuit board deal...

 

[5cardstud]

Thank you joker. this is great for me.

 

[j0ker]

dgree the 4 pin is used to take the high current off the switch. It allows you to use a lower current rated switch, which is what you mostly find locally. The reg has a switch inside that the outer switch actuates.

FYI....I personally would suggest against the Radio Shack regs. Most of the one's I've see from RS are rated too low for this application. If you get one there, make sure it's rated to at least 2 amps. I think most are rated at 50mA which is very inadequate.

 

[MastiffMike]

Dgreen, j0ker answered the 4th pin question and as far as your avoidance of the "whole circuit board deal", you don't HAVE to use the board. It just makes soldering everything together easier but it can be installed without a board.

 

[BobFromChicago]

i been using a 7805 reg from RS for the last 3 months and havent had a problem with it at all.

 

[jace]

You're right j0ker,

Should not have gone there in this thread, when discussing a three lead reg!

 

[j0ker]

I went through 4 7805 trying to make them work. I got the TI reg in and month later it's still doing great. At times the 7805 was getting so hot the ground lead would come loose because the solder would soften. The TI's rock! Can't beat free either.

 

[Ericfixit]

I just wanted to throw it out there that smoothing Capacitors are only used to decrease the ripple from A/C mains after they go through a rectifier bridge (or diodes) and are placed before and after the regulator. There is no need for them on a D/C battery circuit. A 7805 has worked fine (for me!!) because the duty cycle is so low. If you required a constant 5v of 1.7 amps or more than we would need a heat sink or a higher rated regulator. (also a flashlight body can be used as a heat-sink!!)
Just my 3 cents...
Eric

 

[dgreen]

Joker - Now would you do the diagram if I was adding the on off switch as well. I only want the led to light up when the button is pressed. I DO NOT want an led telling me if its on or off. Thanks

 

[j0ker]

Joker - Now would you do the diagram if I was adding the on off switch as well. I only want the led to light up when the button is pressed. I DO NOT want an led telling me if its on or off. Thanks

If you notice I have the LED after the switch and regullator, also notice it's connected to the output of the reg. The LED won't light unless the button is pressed.

Are you wanting a main cutoff switch? If so, you can place it between the battery and the push button.

 

[dgreen]

SO like this??

 

[j0ker]

More like this. You want the resistor between the LED and power, not between LED and atty to power. Otherwise you drop the voltage for the LED and atty. You just want the voltage drop to the LED.

 

[dgreen]

Isnt that the same, or by running wire that I have there Im losing voltage.

 

[j0ker]

The way you have it the voltage passed through the resistor before the atty which will reduce the voltage not only to the LED but also the atty.

 

[5cardstud]

Joker you make it easy. Thank you for the pic. I'm starting to think I had it right the first time I built my mod. I think my problem layed in the protection on the batteries I used from reading another post. Thats another deal though. Thanks again and have a great day.