Verifying a circuit design with voltage regulators

[Vossi]

Need help verifying if this circuit design and use of elements is correct. The goal here is to run a 3v motor, hence I need to make the use of voltage regulators for a constant 3v energy to transfer.

 

[DaveE]

I guess it's ok, sort of. Does your motor really only draw 8mA?

Why do you have 2 caps in series? and why are they 10F!

The diode must be a schottky for only 0.3V drop. This is ok if you choose a big one like 1N5817 et. al. But, only at room temperature and at low current (like 8mA). If it gets hot it will drop more voltage.

Why not just use a linear voltage regulator, where most of the details have been done for you. You'll get better performance with fewer parts. For example 78L33, they cost about $0.50.

 

[Baluncore]

Or get a buck regulator for 90% efficiency.
https://www.ebay.com.au/itm/203108764061

 

[Vossi]

Please help calculate the voltage, current and power of all circuit elements. What is the minimum power rating required for R1 and the voltage regulator?

 

[Rive]

Sorry, but this circuit is just insane.

For the power rating, as it is now you should just take those caps as short circuit since to charge them to 3V will take quite a time. 12V through 1kOhm => you should be able to calculate the power and the current through the (serial) diode too.

Is this some kind of homework? For a real life problem this is just too ... special.

 

[phyzguy]

One question to ask yourself is, where does that 8.7mA go after flowing through the 1 kOhm resistor?

 

[berkeman]

Sorry, but this circuit is just insane.

+1
@Vossi -- Your thread (well, actually your 2 threads, since you multiple posted it) is locked for Moderation. Please send me a Personal Message (PM -- click on my avatar and "Start a conversation") to let me know if this is for schoolwork or not. Thank you.