I also bought a DE-SW050 to use as a Battery Eliminator Circuit (BEC) for powering my BR6000 receiver and Victor 883 speedcontrollers (Yet to test this out :P) and I also bought the variable DE-SW0XX model for using on prototypes I build. Nothing worst then trying to build a quick proto and you only have a bunch of 7805 regulators and no 7812’s left!

The DE-SW033 was a much cheaper solution then going and buying a 2500mAh NiMH pack for my spektrum too, so $15 well spent in my books!

and laptops do already have switching supplies. in fact, switching supplies are probably everywhere where they’re necessary (don’t underestimate engineers =D). MP3 players, the print server i took apart, laptops, computer PSUs, etc–they’re everywhere (except for hi-fi audio, since inefficiency makes things sound better =D). We just don’t see switchers much in the hobbyist world simply because they’re too complex and often not worth the gain in efficiency.

Actually, there are other boost-converter (or buck-converter) circuits out there that are cheaper than this one regulator. Ladyada has a kit (mintyboost) that you can buy that fits into a altoids tin.

http://www.ladyada.net/make/mintyboost/

It’s essencially what you are talking about, but just in a easy-to-purchase kit form.

Also, I didin’t link the TI part. That was someone else. :P

#13: poorly designed switchers do spew EMI throughout the power system, but linear regulators are actually legislated illegal in the EU since they’re so inefficient. Most switchers these days are very “quiet” and in fact significantly help power factor due to their use of a small input capacitor and their ability to draw current over more of the input wave (talking AC->DC here, but DC->DC is still DC->AC->DC :-)) Running at a higher frequency means smaller magnetics as well, and easier filtering.

“Switching regulators could be power efficient but linear regulators does not burn all the power which is more than you need as the producer told in website. So the battery life sould not be increased that much, not even close to it.”

This is mostly incorrect. The efficiency of a linear regulator is a function of the input voltage minus the output voltage. In this scenario, we have a 3.3V output voltage and the input voltage is above 10V. So you are looking at around 33% efficiency, which is abysmal. A switching regulator is almost mandatory here. Now, if the regulator was fed from a lower input voltage, like 4.5V, then the linear regulator would have been a good, cost effective choice. However from 8x AA…

Linear regulators are great for certain things and will always be a staple part of anyone’s electronics kit. But for scenarios where you have a high input voltage and you are drawing more than 100mA, a switching regulator is worth strong consideration.

TI’s switching regulators are nice, but they require you to add your own external capacitors which is kind of a hidden cost.

“9. The manufacturer may have used a linear regulator to reduce EMI, kind of important with a transmitter. Hack probably voids FCC compliance.”

This would be often be the case with many switching reg designs. However with the DE-SW0XX series, the EMI it puts out is almost unmeasurably low. This is because the core of it was designed to be placed in R/C environments which are insanely sensitive to RF noise. Also, whether the RF module on the spektrum receives 3.3V from a linear reg or a switching reg doesn’t really make a difference, it is still 3.3V so there is no change in radiated power so there is no reason for it to change its FCC compliance status. Can check it out on a spectrum analyzer if you like.

“If the entire device really is powered from the linear regulator then it may be because it requires large ammounts of current sporadically.”

Not really. I’ve measured it on the DX6 (different radio, similar technology). There is a constant stream of data being transmitted, and the separate RF module that the regulator powers draws a pretty constant 250mA or so. I would guess that the choice of a linear regulator was a function of ease of manufacturing, time to market, cost of components, cost of engineering a switching regulator etc.

“Now how easily can this be applied to laptops or do they already, given the overall price, have decent regulators in them?”

Laptops already have very good, efficient voltage regulation solutions in there already. I wouldn’t recommend even trying to improve them.

“It has a little heatsink on it, and if you are really maxing it out you may want to put a little fan by it.”

The DE-SW0XX series is designed to continuously supply a full amp and in this application it is supplying about 1/4 of that. You could probably rip the heatsink off the regulator entirely and it would still be fine. However what you have suggested is a good precaution for any engineer to take. Always keep an eye on temperature in enclosed environments, and add airflow if necessary!

Bryan, http://focus.ti.com/docs/prod/folders/print/pt5101.html has a link for getting samples for the pt5101 5v jobber. Getting samples from TI has gotten a little trickier of late thanks to some people taking advantage of the situation. Don’t request too many samples for fear of getting black listed, and IIRC, they wont’t send them to @gmail, @yahoo, @hotmail, or other generic email accounts.

I’ve emailed instructables that their policy SUCKS MAJORLY! and i should be able to directly link to a project!

Almost every single one I’ve looked inside uses a MC34063 1.5A switchmode chip soldered to a tiny PCB with all the coils and caps, etc. To change the output voltage, you just need to swap out the feedback resistor for the appropriate value.

As a bonus, they also have the current limiting function and can withstand anything up to 40V at the inputs.