Cheepo DC Step down adjustable voltage regulators

[Paul2727]

Just ordered 4 of these for test purposes, because they look useful.
Good voltage range both in and out and very small size.
Watch this space for test results and review when they arrive.
Check out the specs and price. Ideas for potential uses welcome
I'm thinking, led lighting use or low voltage one directional motor power source.
Paul.
www.ebay.co.uk/itm/DC-Buck-Step-down-Adjustable-Voltage-Regulator-Module-5v-24v-to-1-8v-3-3v-12v-2A/252510974691?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

 

[dunnyrail]

Just ordered 4 of these for test purposes, because they look useful.
Good voltage range both in and out and very small size.
Watch this space for test results and review when they arrive.
Check out the specs and price. Ideas for potential uses welcome
I'm thinking, led lighting use or low voltage one directional motor power source.
Paul.
www.ebay.co.uk/itm/DC-Buck-Step-down-Adjustable-Voltage-Regulator-Module-5v-24v-to-1-8v-3-3v-12v-2A/252510974691?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

They look like they may be of use, looking forward to your Test Results.

 

[LVT]

Just ordered 4 of these for test purposes, because they look useful.
Good voltage range both in and out and very small size.
Watch this space for test results and review when they arrive.
Check out the specs and price. Ideas for potential uses welcome
I'm thinking, led lighting use or low voltage one directional motor power source.
Paul.
www.ebay.co.uk/itm/DC-Buck-Step-down-Adjustable-Voltage-Regulator-Module-5v-24v-to-1-8v-3-3v-12v-2A/252510974691?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

The only reservation I have with the mini ones is that the adjustment is rather finicky and not very robust. But when dialed in, the results are great— such as led lighting an LGB rail truck. When possible I prefer to use the larger size for more precise adjustment. Wish they came with a built-in bridge rectifier for use in rolling stock but just one extra step. I use the ones with integral voltage indicators as led testers and as a current limiter on a downhill section of track.

 

[Paul2727]

The only reservation I have with the mini ones is that the adjustment is rather finicky and not very robust.

Thanks for your input. LVT. I was expecting that may be the case, which is why I ordered four of em. I liked the fact that a simple cut on the pcb can apparently give a fixed output. A working amperage of 2A should be enough for test purposes.

Paul.

 

[ge_rik]

Crazy, isn't it? 99p including postage from China. I like the way they have various fixed otputs as well as the variable output.

Rik
PS Just ordered 4 and got 24p discount. Wow!

 

[Paul2727]

Crazy, isn't it? 99p including postage from China. I like the way they have various fixed otputs as well as the variable output.

Rik
PS Just ordered 4 and got 24p discount. Wow!

Me too. Gave me a laugh.
I believe they have some form of protection if they are wired with the input polarity the wrong way round. This suggests that they won't work for reversible polarity control. Ie; forward and reverse on a dc motor. However, given their cost and size, I believe it should be possible to wire up a pair suitably protected with one way resistors to a motor. one for forward / one for reverse. Potentially this could allow for slower speeds in reverse than forward if required.
It will be interesting to see how they perform under test.
Regards,
Paul.

 

[dunnyrail]

Crazy, isn't it? 99p including postage from China. I like the way they have various fixed otputs as well as the variable output.

Rik
PS Just ordered 4 and got 24p discount. Wow!

Rik,
In my quest for Battery Power I have been ignoring the setup of Lighting as being ‘just too much trouble’ but also because I do not want to ‘steal’ Battery Life. I wonder if one of these on a Loco (providing I can find the space to fit it) will be just the thing to drive LED’s. Or will it suck out a lot of Battery Juice? I await testing and possible views with interest.

 

[PhilP]

Rik,
In my quest for Battery Power I have been ignoring the setup of Lighting as being ‘just too much trouble’ but also because I do not want to ‘steal’ Battery Life. I wonder if one of these on a Loco (providing I can find the space to fit it) will be just the thing to drive LED’s. Or will it suck out a lot of Battery Juice? I await testing and possible views with interest.

These little 'buck' converters are about 98% efficient.. One of these and a current driver will be great for driving your LED's.

 

[Deleted member 4232]

Moved

 

[wandgrudd]

You'd be right to be concerned about it stealing Battery Life, the board itself requires a minimum of 4.5V for it to function.

As noted by previous comments, the "pot" adjuster is flaky at the best of times, the boards were unable to cope with long periods of use with a sustained high input voltage, of the random ten tried from a batch of fifty, all failed within a day or two of continuous operating, the remainder of the batch were consigned to the nearest dustbin!

Far better, just use a CL2 connected directly to your battery pack, see here for detailed info, https://www.ngineering.com/CL2.pdf

If you are looking for the "miserly" approach to conserving battery power for Led's have a study of this, Make a Joule thief.

at last another big Clive follower in the wild.

 

[dunnyrail]

You'd be right to be concerned about it stealing Battery Life, the board itself requires a minimum of 4.5V for it to function.

As noted by previous comments, the "pot" adjuster is flaky at the best of times, the boards were unable to cope with long periods of use with a sustained high input voltage, of the random ten tried from a batch of fifty, all failed within a day or two of continuous operating, the remainder of the batch were consigned to the nearest dustbin!

Far better, just use a CL2 connected directly to your battery pack, see here for detailed info, https://www.ngineering.com/CL2.pdf

If you are looking for the "miserly" approach to conserving battery power for Led's have a study of this, Make a Joule thief.

Many thanks but I feel that this is all above my Pay Grade, no lights will be the future!

 

[Dan]

I use the LM7805 (7806, 7808, 7809, 7812, 7815) series regulators and 'tune' the voltages with diodes. There are 100ma, .5 amp, 1 amp ane even 1.5 amp versions of some. A diode on the common leg will give you an additional .3 or .7 volts depending on diode type.
4 aAA batteries when fresh are 6.8 volts in series, and the LM7806 with a .7 silicon diode will give 6.7 volts. Great for the pusfix bubble car on track power.

 

[Paul2727]

They arrived today.
My goodness they're small! All four together have a smaller footprint than a 9v battery...
Testing will begin once I've found my micro soldering iron and magnifying glass.
Regards,
Paul.

 

[simon@mgr]

Itty bitty regs.

 

[Degauss]

Mine arrived also. When I unwrapped it I thought they only sent 1 until I looked and saw they are all joined together.
They are very small. Will need to find some fine wire to hook them up as the pads are tiny.

The only reservation I have with the mini ones is that the adjustment is rather finicky and not very robust. ....

I see what you meant by the "adjustment is rather finicky". Need to fine my small screwdriver set.
If in doubt may wire it out to a larger one.
Frank

 

[phils2um]

I picked up some of these cheaply on EBay. The ones I purchased get hotter than hell and two "smoked" on me. I figure they were not even worth what I paid for them - about $1 apiece! I've had no trouble with the somewhat larger ones with blue multi-turn voltage adjustment pots.

Phil S.

 

[Paul2727]

Thanks, I'll keep an eye out for excessive heating.
Obvious these are just for testing. I'm not daft enough to expect perfection for this price.
Regards,
Paul.

 

[PhilP]

Can't say I have had a problem with the pot. adjustable ones.. - Except needing a teeny-tiny screwdriver, and one DOA (out of 170).
They have even survived the input being wrong polarity..