Question about Voltage for a DC motor

[Vandorlot]

I am doing a little project for school where I make a solar paneled vibrabot (like a hexbug). The solar panel that I need to use is linked below. The solar panel gives off 6v and 1.2 watts or 0.2 amps. I cant find a 6v vibration motor that requires this little amps. I found a motor however that requires half the volts but double the amps that the solar panel can provide and therefore the same amount of watts. If its using the correct amount of power just in higher volts would that break the motor?

Solar Panel

 https://voltaicsystems.com/1-watt-6-volt-solar-panel-etfe/

Motor

https://www.amazon.com/tatoko-Vibration-Powerful-Electric-Vibrating/dp/B07Q71F4L9/ref=sr_1_6?dchild=1&keywords=1.2+watt+vibrating+motor&qid=1599256419&s=hi&sr=1-6

[Moonzy]

a solar panel is rated for such an output will not output that amount under all light intensities, if you're not aware

 

it's smarter to have a buffer (like a big capacitor or a battery) and build based on that

[Vandorlot]

4 minutes ago, Moonzy said:

a solar panel is rated for such an output will not output that amount under all light intensities, if you're not aware

 

it's smarter to have a buffer (like a big capacitor or a battery) and build based on that

A battery will be a bit heavy but I am gonna consider using the capacitor. Thanks for the idea.

[Electronics Wizardy]

2 minutes ago, Vandorlot said:

A battery will be a bit heavy but I am gonna consider using the capacitor. Thanks for the idea.

capactior is probably gonna be too small here in capacaity.

 

What light do you have? You need full sun for that power ratings, shade is less than half of that output, indoors is probably 1/10th of that rated output.

[Moonzy]

8 minutes ago, Vandorlot said:

A battery will be a bit heavy but I am gonna consider using the capacitor. Thanks for the idea.

i suggest looking into a voltage regulator to intake the irregular voltage of the panel and output a constant voltage to a cap/some buffer, then drive the motor with the cap.

 

depending on the application and operating condition, you may have to charge up the buffer for a bit before you can operate a motor

 you could look into LiPo packs, they're not too heavy and can store way more than capacitors. though you'll need a proper charger for these (i used to steal battery from my phones lol)

[Vandorlot]

32 minutes ago, Electronics Wizardy said:

capactior is probably gonna be too small here in capacaity.

 

What light do you have? You need full sun for that power ratings, shade is less than half of that output, indoors is probably 1/10th of that rated output.

Bright Sun Light

[Electronics Wizardy]

Just now, Vandorlot said:

Bright Sun Light

Then you want the motor to have about the same voltage, and probably a lower current rating(in case there is a bit less sun). You can also just get any motor, and put a non balanced weight and you have a vibrating motor.

[Vandorlot]

31 minutes ago, Moonzy said:

i suggest looking into a voltage regulator to intake the irregular voltage of the panel and output a constant voltage to a cap/some buffer, then drive the motor with the cap.

 

depending on the application and operating condition, you may have to charge up the buffer for a bit before you can operate a motor

 you could look into LiPo packs, they're not too heavy and can store way more than capacitors. though you'll need a proper charger for these (i used to steal battery from my phones lol)

I actually found a motor that is perfect. It is 6v like the panel and draws 3/4 of the power so it should be fine. I will check out the LiPo packs. Thanks for all your help.

[Vandorlot]

1 minute ago, Electronics Wizardy said:

Then you want the motor to have about the same voltage, and probably a lower current rating(in case there is a bit less sun). You can also just get any motor, and put a non balanced weight and you have a vibrating motor.

Thanks for the suggestion. This is exactly what I did. I found a motor that is same voltage and requires 3/4 of the power. Thank you.

https://www.amazon.com/Fielect-Electric-Airplane-Circular-23000RPM/dp/B0831HCJ17/ref=sr_1_1?dchild=1&keywords=6v%2Bmotor%2B0.15%2Bamp&qid=1599682454&sr=8-1&th=1

 

[Moonzy]

Just now, Vandorlot said:

It is 6v like the panel and draws 3/4 of the power so it should be fine. I will check out the LiPo packs. Thanks for all your help.

you may face some power irregularities when the light level isnt consistent, but should work fine

 

im not too sure how well a panel can handle the kickback voltage from motors, maybe you can look into that

[Electronics Wizardy]

7 minutes ago, Moonzy said:

you may face some power irregularities when the light level isnt consistent, but should work fine

 

im not too sure how well a panel can handle the kickback voltage from motors, maybe you can look into that

to build on this, put a diode the wrong way on the back of dc motors. That way, the diode takes the voltage spike when the power stops, instead of something else in the curcuit.

[mariushm]

Do you absolutely have to use that solar cell or can you buy your own?

 

You can buy lots of motors here: https://www.digikey.com/products/en/motors-solenoids-driver-boards-modules/motors-ac-dc/178?k=&pkeyword=&sv=0&sf=1&FV=-8|178&quantity=&ColumnSort=0&page=1&stock=1&pageSize=25

 

You want vibration motors, so you could further refine it to this: https://www.digikey.com/short/zfvcf7

 

There's motors working with as little as 1.3v .. for example this one is 1.2$ : https://www.digikey.com/product-detail/en/seeed-technology-co-ltd/316040005/1597-1246-ND/5487674

It runs at 0.9v...1.6v so it could probably work well with 1.2v which is a more standard voltage, lots of fixed 1.2v output regulators out there. It also consumes only 75mA (peaks at 120mA when starting)

 

I would use a motor that can work with as little as 1.2v...1.5v DC but can also tolerate up to let's say 2.5v..2.7v ... but the above motor could work, if you just charge the supercap only up to 1.5v

Supercapacitors are typically rated for up to 2.5v or 2.7v so ideally you'd want to use a dc-dc regulator to reduce the solar cell voltage down to a notch below a supercap's voltage rating.. like let's say 2.45v or 2.65v

The dc-dc regulator will slowly charge the super capacitor (slowly is relative, will depend on the capacitance value of the capacitor) and when full, the supercap will be at 2.45v or 2.65v ... when motor starts, the supercap's voltage will start to go down slowly (the solar cell will help keep the voltage up)

 

For example, this one's operating range is 2.1v..3.2v : https://www.digikey.com/product-detail/en/jinlong-machinery-electronics-inc/Z30C1T9870088L/1670-1062-1-ND/9974302

 

Supercapacitors : https://www.digikey.com/short/zfv7zd

 

Lots of them are rated for 2.5v max, or 2.7v max

 

There's a 1.4v max coin cell like supercapacitor there, which would be great if you go with the first motor I linked and limit the voltage to ~1.38v max : https://www.digikey.com/product-detail/en/vishay-beyschlag-draloric-bc-components/MAL219690116E3/4883PHBK-ND/7318588

It's a bit bigger than a CR2032 battery (the one on motherboards) and 90F is quite a bit of charge (it would take minutes to charge up to a reasonable voltage and then it would top up quickly)

 

To convert power from battery, you need a voltage regulator chip, with that solar panel sadly you need a chip that can tolerate up to around 8v because the panel's "no-load" voltage is around 7v.  Sadly, because there's lots of super good regulator chips that can only do up to 5.5v

 

example regulator : https://www.digikey.com/product-detail/en/texas-instruments/TPS627451DSST/296-TPS627451DSSTCT-ND/5355422

 

Configurable from 1.3v..2.8v just by tying vsel1..vsel4 to voltage... there's table in the datasheet

in the picture, it's tps62745 which is the 1.8v..3.3v output version (link is for tps627451), and 1.8v is configured by setting all four to 0 (by tying them to ground)