How to use solar power to store power into power pack, then move the motor ?

[tengyy]

Can someone recommend me a suitable circuit ?
the solar power plate are around 2~10V, and the motors are around 3 to 12V

 

[Audioguru]

We cannot recommend a voltage stepup circuit without knowing the maximum starting (stalled) current of the motor. Is it a few mA or is it many Amps?

The power pack is a battery, isn't it? Then it will charge to maybe 12V from the voltage stepup circuit. The solar panel will not produce much current when its unloaded voltage is below half of its maximum voltage.

 

[tengyy]

I do not fixed the type of motor. as long as it can move. Power pack might is battery, but i not sure how to control it

 

[Audioguru]

If you have a rechargeable battery and you charge or discharge it wrongly then it might blow up or catch on fire and injure someone.
To charge a battery you need a charger circuit designed for the size and chemistry of the battery.
You must not overload a battery with a motor that draws too much current..

 

[tengyy]

Yes, I have already build my charger circuit with 4 set 1.5V battery, but i don't know how to invert it to provide power to control motor or microprocessor.

 

[EagleTalonTim]

If you are wanting to power a microprocessor, you need to more than likely reduce the power down the the required voltage as needed by the microprocessor. Most will either be 3.3V or 5V. Look up voltage regulators and how to use them. Switching regulators are more difficult to wire up and usually require a PCB unless you get a pre-made switching regulator like this one R-78E5.0-0.5 which is a 5V switching regulator. You will need filter caps across the output and ground to prevent a ripple in the voltage. You can also use LDO (Low drop out) regulators which would be easier to wire up.

To control the motor with your batteries and the microprocessor, you will need to use an NPN transistor to control the low side (ground) connection to the motor. One lead of the motor will be connected directly to the battery positive, and the negative of the motor will be connected to the collector of the NPN transistor which will be controlled by the microprocessor. You will need to put a current limiting resistor on the base of the transistor and the value will depend on the voltage and current source ability of the processor. The Emitter of the transistor will be tied directly to ground (Negative side of the battery).

When switching a motor on and off, it will create what is called flyback voltage which needs to be controlled via a diode across the motor's leads. This will prevent unwanted voltage spikes getting to your processor and causing unwanted effects. Hope that helps!

 

[Audioguru]

Does anybody know what chemistry your battery uses? You forgot to tell us.
The battery charger circuit in your other thread also does not say the type of battery and the charger circuit makes no sense.
Nobody makes a rechargeable 1.5V battery cell. Ni-Cad and Ni-MH average 1.2V but are 1.4V when fully charged. They are 1.0V when they should be recharged.

 

[tengyy]

it is DoublePow brand Ni-Mh batteries with 1250mAH and 1.2V

 

[Audioguru]

Your battery will be 4.0V when it should be disconnected from the voltage stepup circuit and will be 5.6V when fresh off the charger.
This battery can supply about 10A for maybe one or two minutes or 1.25A for one hour.
When the battery voltage is stepped up then the current from the battery is also increased causing the battery to discharge faster.

Since your load is a 3V to 12V motor then you need a voltage buck-boost circuit, not a voltage stepup circuit.