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Posted by Dani123 | Apr 18, 2014 @ 02:39 AM | 3,162 Views
Quite a lot this time
Posted by Dani123 | Feb 20, 2014 @ 01:59 PM | 4,466 Views
I'm continuing with the evolution of these switches.
Have changed the hall latch that I use to one that supports low voltage down to 2.5V, thus making it possible to use with 1s LiPo. Next, the MOSFET is different, it is rated up to 8.5A ant still so tiny...
The blinking LED stays the same, I like it. The overall size and weight are pretty much the same, still under 3gr and very small.
The switch does not drain the battery once connected but in off state, it is nice feature. maybe I'll get rid of these mechanical SJ and move to these : )
Posted by Dani123 | Nov 19, 2013 @ 02:24 PM | 3,475 Views
Made a few more of these. I'm making quite consistent packaging and weight factors, very happy about it.
The greatest part of it, when it is switched on, the current goes through the mosfet which is a solid state component, no mechanical parts, thus reducing he potential failure points. While fulfilling the function of a switchjack, it is lighter and more compact.

Enjoy, Dani
Posted by Dani123 | Oct 22, 2013 @ 04:34 PM | 4,834 Views
Trying as usual to make it smaller and more convenient.
Each unit in the pictures weights around 3gr (the parts are ~0.8gr, the rest is added by the leads...)
I left the blinking led, but made the leads go from one side only, this is more practical in my opinion. A small glue dub for the night between the leads and the pcb, heat shrink in the morning.
Will keep you posted..
Posted by Dani123 | Aug 15, 2013 @ 02:17 PM | 4,148 Views
I try to improve the unit.
This time I added a blinking red led and minimized the physical dimensions. Another thing is I changed the transistor to a 2.7A rated IRFL014, it is bigger and easier to use. Even with this addition the unit is still under 3gr.

I am very happy with this attempt, but I still managed to make it even smaller and compact. Next it will be put in one of my DLGiis.
Posted by Dani123 | Jul 15, 2013 @ 02:56 PM | 3,966 Views
Hi guys

This time I will post my efforts to make magnetic switch. Magnetic switch is kind of hi tech switch jack - no moving parts, no touching, really great.
I followed the guidelines from here: http://www.bristolwatch.com/hall_effect/

There have been quite a few of them from different manufacturers, so I decided to give it a try, here is the first effort in pictures.

The heart of the unit is a latching hall effect switch, OH1881 unit. Hall effect switch simply closes/opens a circuit once a magnetic field is present. Latching type means that the circuit stays closed/open after the magnet is removed, until it comes close again.

I had to add a mosfet (AO3400) that will handle the relatively large currents (the latch itself cannot do that), added a resistor and indicating LED.
The only thing you have to do in order to turn it on is to pass by the unit with small magnet, to turn off, pass again with the other pole, very simple.

For now I'm very happy it works great, I will try to improve the enclosure in the near future.

Enjoy, Dani
Posted by Dani123 | Apr 05, 2013 @ 07:21 PM | 4,534 Views
Made two more units today, pretty cool at 5.4gr each.
Posted by Dani123 | Mar 22, 2013 @ 02:54 PM | 5,172 Views
Well, I continue improving the unit, and this time I think this is it.
I've arranged the components slightly different I was able to add the buzzer on the board.
The unit came just a little longer than the previous model, and I was able to save some weight...
Now I'm happy with the outcome!
Posted by Dani123 | Mar 10, 2013 @ 02:43 PM | 4,199 Views
Hey guys

Made a few more of these over the weekend.
I'm currently pretty settled on the 6 gr. per unit. A VERY amateur video of the performance can be seen here :
Voltage regulator, 2s to 5v, with low voltage alarm. (4 min 10 sec)

I flew my Akcent 2 with one of these inside - solid performance, no issues at all.
I'm getting good feedbacks about the regulators.

Enjoy, Dani
Posted by Dani123 | Feb 16, 2013 @ 01:57 PM | 4,493 Views
Hi Guys

Wanted to show you the new version of the regulator with low voltage alarm. I needed one more for my Akcent 2, so I made a batch of three units.

In this one, I think, I implemented all of the stuff that I learned along the way. The resulting unit is neat, small and lightweight. Can be tucked in narrow spaces common for DLG fuse. I might be offering these in the near future along with my basic units.

Enjoy, Dani
Posted by Dani123 | Feb 08, 2013 @ 02:14 PM | 5,420 Views
This one is dedicated to relatively high capacity 2s lipos for your DLG. You typically can't find suitable lipo packs above 400 mAh to fit in the nose.
The resulting pack is small in width and depth dimensions, thus making it easy sliding way forward the DLG nose. It is more reasonable way for balancing the cg than adding lead in the nose .

I make those from 1s 600mAh cells that you can find all over the internet, I think they are used for micro helis.

The pictures speak for themselves, you can see the comparison to NiMh 400mAh pack in size. We already gained some weight but increased the capacity and of course the flying time greatly.

Enjoy,...Continue Reading
Posted by Dani123 | Dec 02, 2012 @ 01:55 PM | 4,960 Views
I made an additional design of the voltage regulator and low voltage alarm unit. The final piece is almost perfect
This one is based on an ams1117 1A regulator unit with appropriate capacitors and a microscream circuit attached to it. The alarm in this one is set to 7.2v and the whole thing is 6g in weight.

The regulator went through my usual testing procedure - it cycled three servos constantly for almost 4 hours on a 500mAh 2S battery, before the alarm went off.

This one goes into my next DLG.
Posted by Dani123 | Nov 22, 2012 @ 11:12 AM | 5,017 Views
A fellow member here on RCG asked me to make him a few units, so here is the making process in pictures

The heart of the regulator is 1A ams1117 5.0 unit, coupled with capacitors on the input and the output. I put everything on a small piece of PCB, it really makes everything nice and in order. As you can see the main unit is very light and the leads add more than twice the weight. When everything is soldered, I like to glue the leads to the PCB with drop of thick CA, it secures them and makes the solder points stress free.
The final step is the shrinking of the whole unit, the final product is about 3gr total - I'm very happy.

Posted by Dani123 | Nov 12, 2012 @ 02:20 PM | 5,227 Views
Back to my search for small and lightweight 2S lipo regulator, I've found this tiny AMS1117 unit, which is surface mounted component.
It regulates voltages as high as 12v down to 5v. It is very tiny and light, the downside it is only 1A current rated.

I gathered the required components and soldered it this evening. First of all, SMD component are really easy to solder , there is really nothing complicated when you have the right tip for the soldering iron (there are great videos at YouTube).
For now I had this electrolytic capacitor, later I will replace it with tantalum one,which is smaller and lighter.

As you can see, the most weight is from the connectors and wires, the unit works. Later I will put some shrink at it.
Posted by Dani123 | Nov 02, 2012 @ 05:35 AM | 5,299 Views

So after the previous attempt, I did a little refinement.
This one is almost perfect: it has 2A voltage regulator from 2s to 5v and a voltage alarm circuit adopted for 7.2v alarm voltage (3.6v/cell). The buzzer is attached on leads and not on the board - more convenient I think.
If you compare it to the previous version, the difference is noticeable...
I'm almost happy with this one, will try to make it more compact...

Posted by Dani123 | Oct 13, 2012 @ 10:49 AM | 5,357 Views
A couple of weeks ago I was flying my SG with 2s lipo and voltage regulator (see my other blog entries).
Well, after 2 hours + I planted it in the ground due to low voltage, the juice simply ran out and I didn't track the time, my fault completely.

After the incident I came to two conclusions:
1. I need to be aware of the flight time.
2. What about voltage alarm?

There are some commercial units, but being me ) I wanted something DIY.
After searching the forum and the web I came across this nice design called the Micro Scream: https://www.rcgroups.com/forums/show...=LiPo+Screamer.

It is really simple, 6 components in all, and can be adopted to any voltage threshold (I have it on 6.6v now) that I like. After soldering one and validating it's functionality, I had an idea.
Why not integrate the voltage regulator and the micro scream in one unit ?
Again, there are some commercial units, but I like challenges

So, after one night with soldering iron, I ended up with this unit. It is completely functional and the concept is validated.

Next, I would like to make it smaller, to put the components closer together and reduce the volume and of course the weight.

I will update upon progress.
Posted by Dani123 | Sep 25, 2012 @ 12:57 PM | 5,468 Views
Hi guys

After the first success, both building and flying, a couple of friends asked me to do a regulator for them also.
This time I wanted to make it neater and more compact, mainly flatter so one could tug it in tight spaces in DLG fuse.

Today I made two more, experimenting with different component placements, and this time I used a PCB board to help with that.

In the pictures you see v3 and v4 of the regulators. In the final version I put the large capacitor at the side, so I've got a more flatter design.
I think that I've settled on the v4 version, I really like the minimal cross section.
Posted by Dani123 | Sep 20, 2012 @ 02:38 PM | 5,926 Views
Hi guys

So, I received my 2s lipo this week and finally wanted to install it together with the homemade regulator inside my SG pod, here it goes.

First, I wanted to changed as little as possible in the pod, so upon inspection I changed the JST female from the original regulator build to regular servo female plug. I will install it after the SJ in the fuse, so I will still able to charge the battery through the plug (without balance of course).

Second, comparing the two batteries, I already have a gain of 10gr, with the regulator being around 5gr, I added another 5~6 in the nose. Taking into account that the lipo won't come as forward as the original pack.

Removed the battery, some wires were re-routed so it will all fit inside in the best way. All fit snugly in. Tomorrow I will see about the added flight time.

...Continue Reading