I have a requirement to connect a 12VDC Solar-panel to a 1.5VDC device. Since the 12-volts may fluctuate, I need some sort of regulator? If so, what type?hat don’t have specified Category.
Welcome to the forum!
You want a switching regulator because a linear regulator will waste almost 90% of the solar power as heat. I recommend a module rather than a roll your own solution because of the amount of engineering required to roll your own.
To specify an actual part we need to know the maximum amount of current your 1.5 device requires.
An easy to use switching supply line that I’ve found to work very well is the OKR models from Murata.
A couple of examples are:
https://www.digikey.com/product-detail/en/murata-power-solutions-inc/OKR-T-1.5-W12-C/811-2782-ND/3674288
https://www.digikey.com/products/en?keywords=OKR-T%2F3-W12-C
They are an adjustable output regulators that only require one resistor to set the output voltage and work with 4.5 to 14VDC of input voltage.
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Thanks… The examples you were very helpful! Forgot to mention, need waterproof too. So I am looking at this: https://www./itm/Waterproof-Adjustable-DC-DC-Buck-Voltage-Converter-8-22V-to-Regulated-1-15V-3A/162787166486?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l9372 I read the work “regulated”. If the input fluctuates, will the output remain steady?
Correct, that is part of regulation.
Other parts to regulation include that the output voltage remain stable over changes in current draw, temperature, and time.
I like a challenge(no matter the size), then a solution
With all the helpful input… Here is what I came up with. Thoughts?
You need to add a charge controller between the solar panel and lead acid battery if you don’t want the 24V from your panel to destroy, possible explosively and/or with large flames, the 12V battery.
The battery only allows the lawn ornament to operate when there is no sun. So if operating only during daylight is OK, skip the battery.
FYI - rechargeable batteries are dangerous when not handled properly. Anyone who wants to play around with them should take the many hours needed to learn the physics, chemistry and engineering to keep their family and property safe. If a person isn’t willing to put in the hours, the only safe alternative is to buy a complete solution designed by a company that has the safety expertise.
Thanks for all your help… Here is what I put into operation. It may not look pretty… But it works!
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Good job, getting it to work is way more important than making it pretty, you can always work on making it prettier later.
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Pondering an enhancement… The addition of an on/off light sensor. Given the design… Suggestions?
Also, is it best to use rechargeable or solar batteries? Then, what specs should I be looking for?
Ditch the batteries entirely and use only a solar panel. Then when there is no light there is no power.
A good rule of thumb for reliable circuits, the fewer parts used the better.
There is no such device a solar battery, I suspect you saw some weird made up marketing term meant to sell something for more money than it’s worth.
As to the specs for a recahgebale battery you absolutely must follow the specs from the manufacturer of the solar charger or else you risk damaging the charger and/or batteries, and could even cause a fire.
I did try it. No sun… No fluttering-butterfly… 
I believe you may be correct… Outdoor path-lights have batteries labeled “Solar”.
The solar-panel’s function is to re-charge batteries… Re-chargeable it is! 
Which is what an,
would give you, so success by removing parts.
Yep, a made up marketing term to hopefully sell the customer their rechargeable batteries, usually for way more money than the batteries are worth. Usually those lights use NiCad’s because they work better for charging and discharging at colder temperatures than other cheap rechargeables, and you can get solar panels specifically rated to charge them safely with only a single diode in the circuit.
That is because the lights are only used when there is no sun and therefore no solar power available.
Returning for more help…
Since the motor is running all-night, by morning there is a noticeable slow-down until the sun hits the solar-panel.
Got solution(s) to fix this?
Note: I exchanged the dollar-store rechargeable batteries with brand-name rechargeable batteries. There is a notable improvement in the speed and operation of the butterfly.
You’ll need to use larger mAh capacity batteries with a larger solar panel and a charger that handles the larger solar panel and batteries. Moving from AA to C size will more than double the battery capacity and it will require a more than double size solar panel.
I do have a larger 12-v solar panel that I can adjust the wattage down. What input wattage would you suggest?