Issacsutt

modified 5 years ago

LED Test circuit for GerkI

134

353

03:45:59

Check out @GerkI’s post:  http://everycircuit.com/circuit/5184900070899712 
for more details if interested in the whole story.

...But basically this is a voltage regulator circuit I had designed to drive his 6 LED matrix and touch switch.  It actually took several different designs and attempts before finally ending up with this one.  EC does not accurately simulate it, but when built in real life without the 100nF capacitor, it oscillates like crazy anywhere between a several hundreds of kHz and up to 1.8MHz even with a heavy load on the output.  So that capacitor is absolutely crucial and hence, was the biggest improvement for the entire design.

Tested with 5v supply.

Ignore most of EC, because I have taken several tests and measurements, and the output never went above 3.08V even with no load, or dropped below 2.8v with even a 15 Ohm resistor as a load, and never dropped below 2.92v with a 37 Ohm load.

I did alter 2 resistor values slightly to make it much easier to component wise, and the other one was crucial to change, the 500 ohm.

1. Changed the 500 to 100
2. Changed the 6.7k to 6.8k
3. Added a 100nF capacitor

*The 1pF capacitor between ground is only to fix some previous simulation issues...  if you plan on actually building this, nothing will work with that 1pF capacitor there, simply replace with a wire*

published 5 years ago

Gerkl

5 years ago

Maybe I should use this HT7330-7? From the diagram coming with RH6030?

Issacsutt

5 years ago

Ok, if that didn’t work either, than let’s take a small step back, using this circuit without the additional transistor, can it at least function with 1 LED???

Gerkl

5 years ago

No, it Doesn't. Touch sensor not reacting at all. Even one LED connected directly to power still really dim.

Issacsutt

5 years ago

I’m pretty sure it doesn’t feature that circuit, but is rather just showing an example of how to use the ic with an external circuit.

Issacsutt

5 years ago

Can you plug the power into the touch sense sense circuit and measure the voltage access sensor the output with a multimeter, and then measure across the output with the resistance function? Maybe Try to find out if it is driving the output directly to vcc/ground, or if it is instead just shorting its 2 output wires together through a semiconductor?

Issacsutt

5 years ago

**Measure voltage across the output of sensor** ...sorry for the typo, dumb fuckn autocorrect is causing problems.

Gerkl

5 years ago

It shows me 2mV across the output of sensor. Touched sensor - no reaction. Positive is passing thru and Negative going thru the circuit. Connected directly to battery and it works. Same voltage on output as on input. Looks like there is not enough current is going to the sensor because even 1 LED connected straight to power is dim.

Robert_Kidd

5 years ago

@Gerkl, thanks for the Amazon link which I had to copy longhand as on an iPhone EC doesn’t let you copy & paste or run from link. Phew! Right, I think you are using an 850mA hour. You can proceed however you like of course but I’d like you to take a moment to consider something.

Gerkl

5 years ago

@Robert_Kidd, Sorry for inconvenience, I had no idea that copy/paste doesn't work on iPhone. It works on my browser and android devices.

Robert_Kidd

5 years ago

I don’t know why you have decided to use a touch switch (perhaps because it’s cool?) but I wondered if you intend to have a physical power on/off switch? I suspect not, otherwise why go for the touch switch! Assuming I’m correct about that then, with the LED’s off the 850mA hour battery will power your unit for approximately 850/30 = 28 hours. It’s your choice but I would ditch the touch switch and just use a physical toggle switch. You seem to now have a circuit that reliably gives you 3V so you’d get around 28 hours of actual use on one battery charge. Having said all that, if you are not using the touch switch then you don’t need this 3V regulator anyway - you just need battery, switch, current limiting resistors and LED’s. Simple is best but it’s your choice of course.

Robert_Kidd

5 years ago

I meant to point out that your 3V regulator circuit consumes 30mA with LED’s off. Happy to explain further if I’ve not made this clear.

Gerkl

5 years ago

Yes you right I decided to use touch sensor because it is fancy and perfectly fits my project. I wish I can share the picture. Unfortunately physicals switch not gonna be a best choice. At first I used two paralleled CR2032 with touch sensor and LEDs. But they did not last long. Battery worked only for 8 hours. I guess since touch sensor have built in voltage regulator I will use just battery touch sensor and LEDs with current limiting resistors

Robert_Kidd

5 years ago

What, the original touch sensor has an internal regulator? Or have you got a different one?

Issacsutt

5 years ago

I wouldn’t give up on the touch function though, it’s definitely still possible... LET THE DREAM COME ALIVE!!! I seriously believe that you just bought the touch sensor from a bad source because their site appears pretty sketchy to me. But I have done quite a few touch sensitive projects before and I know that it is possible. Also I build everything I do from discrete components and have even made a touch switch that powered on and off my tv before, and I did it using nothing more than transistors resistors capacitors a mosfet and a relay! I’ve also built a capacive proximity touch sensor before that could even sense my hand up to like 5 inches in front of it (that one I built from almost entirely discrete compents also, except I just used 1 op amp. Don’t give is all I’m trying to say, because otherwise you’ll just continue to think that you never could have done it, and that’ll only hold you back. You honestly probably just got screwed by whoever this company is you bought it from, cause they also failed to provide any details on how to properly drive something with it... no specs other than input voltage...I would’ve been thinking wtf 🤬$@@&!?!?

Issacsutt

5 years ago

Let me know if you still wanna keep trying this, because I will 100% continue to help you through it until we get it working... wether we have using a different touch switch or even different driving circuit, it doesn’t matter to me, we’ll get it!

Issacsutt

5 years ago

Believe me when I say I have failed so many times at personal projects, but I don’t care cause I know I can make it work and I won’t stop till I do, and that mindset has led me to many discoveries and also some pretty cool successes eventually.

Gerkl

5 years ago

@ Issacsutt. I am not planning to give up. Because I need that project to be finished since I started. Just because I am not electronically educated enough I am just looking for every different possibilities to get it done. If one thing doesn't work, move on and try something else. That is the only small size touch sensor I could find on the market. I will try to find the way to share picture of my project so you have an idea of what I am trying to achieve.

Gerkl

5 years ago

Thanks guys for help, I just don't want to waste anyone's time.

Gerkl

5 years ago

First thing first. After adding capacitor LED connected straight to power ( no touch sensor) is dim. Doesn't matter 1 or 6 LEDs. How to fix that?

Issacsutt

5 years ago

Ok I’ll just wait for the picture for now then, if you find a way that is. I tried creating a shareable link once, but when I tried clicking on it, it wouldn’t work, but android may have better luck with that, as I have an apple right now that I had just been trying sense last year

Issacsutt

5 years ago

Apples not as easy so far, so I’ll probably be trying a google pixel soon. I have Samsung a couple years but I’m not gonna get one again unit they quit marking their phones so freaking giant and throwing a million f’n cameras on it; bing back the small phones!!! Like the iPhone12 mini, but for android

Robert_Kidd

5 years ago

I assume you are talking about a different touch switch that includes a regulator? I know the original switch doesn’t have?

Gerkl

5 years ago

maybe there is another circuit can be build for this?

Robert_Kidd

5 years ago

If a touch sensor switch is a must then surely the statring point is to find one you like.

Gerkl

5 years ago

http://www.filedropper.com/pxl20210117224738984portrait

Gerkl

5 years ago

http://www.filedropper.com/dsc0068 http://www.filedropper.com/p1010108

Gerkl

5 years ago

some files if you interested

Robert_Kidd

5 years ago

Yes. Ok. Is the purple thing your project?

Gerkl

5 years ago

yes

Robert_Kidd

5 years ago

What’s it for?

Robert_Kidd

5 years ago

I was expecting something made of wood lol

Gerkl

5 years ago

http://www.filedropper.com/dsc0064_1 http://www.filedropper.com/pxl20210117224700881portrait it is made from wood.

Robert_Kidd

5 years ago

I see. Looks good. But what’s it for or don’t you want to say?

Issacsutt

5 years ago

Ok cool, so I guess all the LEDs are behind the flower thing

Gerkl

5 years ago

That one is one of the 7 chakras. I paint them with UV paint so they can light up at night. Middle piece is my LEDs with touch sensor on top.

Issacsutt

5 years ago

Is the touch sensor able to drive anything at all consistently when powered from the voltage regulator circuit?

Gerkl

5 years ago

Without capacitor and with 4V out. Yes.

Issacsutt

5 years ago

Ok that is so weird.. Especially the without capacitor part.

Issacsutt

5 years ago

So then when you say at 4v, do you mean powering the sensor with 4v or LEDs with 4v, and to get that 4v are you just bypassing the regulator?

Issacsutt

5 years ago

Would you possibly be able to redraw the circuit with the changes that you know makes it work and drives the LEDs?

Gerkl

5 years ago

4V mean connecting directly to battery. But LEDs are too bright, i don't think they will last lond. I didnot test it for how long battery will last. I was going to drop voltage to 3v because it says that touch sensor works of 3 V. But looks like it is still working off 4V as well. That is why I think that there is no need to drop the voltage anymore since it is causing too much troubles to build as well. Jus need to adjust resistors to limit current for LEDs.

Issacsutt

5 years ago

Hey in your picture of that touch sense circuit board, are those two red wires soldered together, cause it kinda looks like it? Also can you find out where the three pins on the AOLA chip go?

Issacsutt

5 years ago

Also thanks for verifying the 4v thing, I think I might have one more idea, but if that doesn’t work then maybe just use LEDs with resistors directly to supply like you said worse case scenario.

Gerkl

5 years ago

http://www.filedropper.com/p1010109 This is better picture. Yes both reds soldered together. Looks like Middle goes to Negative Out, Left goes to resistor, Right can't see it.

Issacsutt

5 years ago

***Updated the post cause I just noticed robertkidd’s comment from earlier about it consuming 30mA when off... unfortunately you cannot really get rid of that without making the circuit more complicated, but you can easily fix that by changing the location of the switch, which I just did. Check it out if you want.... Doesn’t consume any current at all when off now.

Issacsutt

5 years ago

Ok thanks, I’m gonna study the new picture here shortly... where exactly have you been putting the red and black leads with the regulator circuit though?

Issacsutt

5 years ago

Also, I can’t find a datasheet for the AOLA part, but I can’t make out what the whole part number is on that chip either, do you know?

Gerkl

5 years ago

http://www.filedropper.com/ao3400a I was not able to read it too. That is I found on internet. http://www.filedropper.com/schematicledpowercurcitboard2021-01-1720-40-58 http://www.filedropper.com/pcbpcb2021-01-1217-28-202021-01-1720-40-16

Issacsutt

5 years ago

I can’t get any of those links to work for some reason.

Issacsutt

5 years ago

I’ve been using https, but what’s different with these links this time is it tries to have me actually download and open in an app, I used acrobat but it says it’s corrupted or missing info or something like that

Robert_Kidd

5 years ago

Try again, they all work for me. Not the http https issue?

Robert_Kidd

5 years ago

That’s odd.

Robert_Kidd

5 years ago

I’m just downloading on my iPhone like before.

Issacsutt

5 years ago

Yeah nothing works, however I never had a problem with the other ones

Gerkl

5 years ago

http://www.filedropper.com/schematicledpowercurcitboard2021-01-1720-40-58_1 http://www.filedropper.com/pcbpcb2021-01-1217-28-202021-01-1720-40-16_1

Gerkl

5 years ago

try those links

Robert_Kidd

5 years ago

They work for me but then the earlier ones did too.

Robert_Kidd

5 years ago

@Gerkl, I’m a bit lost at the moment as to where this is heading but I notice that in your circuit diagram you still show the 510 Ohm rather than 100 Ohm which it was changed to a while back. May be intentional but thought it worth pointing out.

Gerkl

5 years ago

@Robet_Kidd, To be honest I am also lost. I am not updating circuit because I don't see the point. It is not accurate, I can't duplicate my touch sensor, etc. I am waiting for response from Issacsutt about why even one LED is dim without touch sensor but added capacitor.

Issacsutt

5 years ago

Honestly that makes no sense, because it works pretty well for me with all 6 LEDs, but my guess is maybe dropping the supply voltage down to 4 or 3.7v whereas I was testing with 5v might be why... so I’m gonna go buy I guess a couple AA batteries to do some more testing and see if that makes any difference for me. Chances are if it does though, all we’d have to do is adjust a resistor value or two, Hopefully.

Gerkl

5 years ago

I just noticed that you moved switch closer to capacitor. How can I implement that with my touch sensor?

Issacsutt

5 years ago

You wouldn’t be able to implement that, unless you powered the touch switch directly from supply and then used its two output wires as if it were the switch. But just make sure the polarity is right, ground to resistor, positive out to capacitor/base of pnp

Issacsutt

5 years ago

Do you have a potentiometer?

Gerkl

5 years ago

no I don't. I did not have anything. Just start buying some resistors, transistors and etc.. just general stuff.

Issacsutt

5 years ago

Oh wow, nice!

Issacsutt

5 years ago

Ok, well what you can try is increasing the 22k resistor that goes to the base of the NPN or increasing the 470 ohm resistor or decreasing the 6k8, which doing so without a pot is still possible just not very convenient, but it’s all you have to work with right now. I would just start manipulating one of those values in the direction I mentioned above, but only change 1 of them at a time and if it doesn’t help set it back to its original value before trying to manipulate the others. Best way to play with the values is keep swapping the closest next size up or down. The downside to swapping these values is it probably won’t regulate as well at higher voltages, especially if your swapping the 470 ohm... but if your only gonna be using a fairly low voltage battery anyway, than those extra protection features really aren’t to necessary. When you are experimenting with different values though, do so starting out with the lowest operating voltage that you intend it to operate on, and then adjust that supply voltage back to max intended operating voltage to see how it does, if nothing gets hot even after several minutes then you should be ok 👌

Issacsutt

5 years ago

How is the project going so far? Has changing any of those resistors helped?

Gerkl

5 years ago

I did not try it yet. Busy at work.

Issacsutt

5 years ago

Gerkl

5 years ago

Hi guys. Sorry for no response for a while. I am really busy at work working long hours. I will update once I have time to test it

Robert_Kidd

5 years ago

Not a problem.

Issacsutt

5 years ago

All good, no worries

Gerkl

5 years ago

OK. Finally got time to test those changes. I had to rebuild my board several times but finally made it work. Increasing 22K resistor did not make any changes. I did increased 470Om to 800Om. Now I am getting 3.11V without load and 3.05V while LEDs are on. I did not use resistors on LEDs . Now running to see how long battery last or how long it will take to drop bellow 3V so touch sensor stop working. I also tested with 1K resistor instead of 470 and it was giving me 3.2 V. Maybe will go with 1K option for longer run until touch sensor will go down. I want to thank you guys for the help.

Robert_Kidd

5 years ago

Will be interested to know what run time is.

Gerkl

5 years ago

I got interesting results. On constant load battery last 11 hours. Without load battery last about 17 hours. Looks like it is draining current without load anyway. Any ideas how to fix that? Thank you.

Robert_Kidd

5 years ago

For my part I’d like you to start with a new post if you can be bothered as I don’t know what circuit you actually have now.

Gerkl

5 years ago

I am using same circuit as here

Gerkl

5 years ago

I just changed 470 I'm resistor with 800 I'm.

Robert_Kidd

5 years ago

Really? So you have a switch in the base of the top transistor? And is it a mechanical switch as shown here or the touch switch you purchased? Issac may know what you have but I’ll not be able to offer useful advice unless I’ve definitely got circuit right :-)

Robert_Kidd

5 years ago

I’m thinking of building it although I don’t have the touch switch which is quite low cost until I want to get it shipped to uk!

Gerkl

5 years ago

I changed my original circuit to show how everything is connected in real life.

Gerkl

5 years ago

By the way, I was looking for some other options online for voltage regulator and found some interesting ideas. I build one of them. It is based on HT7330 voltage regulator with several capacitors. No offence to Issacsutt but it looks more promising. Less components, smaller build size and longer life time. So far it has been running on 6 LEDs load for 24 hours and still ON.

Gerkl

5 years ago

http://www.filedropper.com/3vvoltageregulator

Issacsutt

5 years ago

Wow awesome, what is this other circuit you found, I’m curious to see how they designed it? Also glad to hear it’s all working now. Does that new other circuit use mosfets maybe?

Issacsutt

5 years ago

Oh never mind I saw it in the link. I’m not surprised it’s so efficient to be honest, your using an ic now, so it’s probably got dozens of transistors on just that one little chip, and maybe even some mosfets which have such a better on resistance than BJTs. But cool I’m glad it’s working well now :)

Robert_Kidd

5 years ago

Think you’ve found a good solution. Had intended to come up with an alternative for you but been too busy. HT is a good choice and you presumably have your circuit working with the infamous touch switch?

Gerkl

5 years ago

wow. third day on constant load and still running. Yes I am still using that touch sensor.)

Issacsutt

5 years ago

Dang that’s pretty sweet, we’re you running it nonstop??

Issacsutt

5 years ago

Like even through the night and everything..?

Gerkl

5 years ago

Yes. it is running nonstop. So far 72 hours. Before I counted hours, now counting days. LOL.

Gerkl

5 years ago

It is not that bright but I like it. It is bright enough for my project. Yee I just turned it On and left running, sometimes tapping touch sensor to see if it still reacting. Battery is 700mAh. Really interesting for how long it will last.

Issacsutt

5 years ago

Wow amazing

Issacsutt

5 years ago

...I may have to research a datasheet for this voltage regulator and see what’s happening. I’m positive it’s all in the magic of mosfets though

Gerkl

5 years ago

day 5. Still running.

Robert_Kidd

5 years ago

That’s good. You could divide battery capacity by current consumption and get a reasonable idea of lifetime.

Gerkl

5 years ago

still ON but les brighter. 2.8V. It should die long time ago. LED max 6x20 mAmp. Battery is 700 mAmp. I am not sure now what is actual LED current consumption is. Looks like totally it last 120 hours with good brightness.

Robert_Kidd

5 years ago

I was thinking you might not have a meter to measure the current. As LED’s tend to be much brighter these days and you said they weren’t particularly bright it’s possible they might only be taking (say) 10mA each which would potentially double your expected time. Anyway, nothing like a real life test :-)

Issacsutt

5 years ago

If you want, you can place a 1 ohm resistor in series with the LEDs (between ground may be easier) and basically use a multimeter to measure the voltage drop across that resistor which will be exactly the same as the current... so for example, if you measure say 98mV then the current is also that value; (98mA) because i=VR; so if R=1, then it’s just i=V.

Robert_Kidd

5 years ago

If you were going to do that you might as well put resistor in series with battery and measure total consumption.

Robert_Kidd

5 years ago

Only slightly different but if you’re going to calculate expected battery life you might as well start with accurate values.

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