DC/DC Converter (Miniature Remote Control Solar Car)

[devonsc]

However, the biggest problem is likely to be the transformer required, you will probably either have to wind it yourself, or have it custom made - neither method is likely to be cheap or easy!.

Real sorry as I've not deal with transformer before this and I thought we can get the appropriate ones in the market? Nway, thanks for that advice...Now I have to reconsider what should I do to expand my portion of the project without this...

Needs advice / suggestions / opinions badly... :cry: :cry: :cry:

Btw, issit advisable or practical to implement a PIC microcontroller for the battery monitoring portion? Or should I just implement a DOT matrix driver and develop a circuit to monitor the condition of the battery? But if i were to implement a PIC microcontroller, what are the features can I include in it? Any suggestions? Please?

 

[Nigel Goodwin]

Btw, issit advisable or practical to implement a PIC microcontroller for the battery monitoring portion? Or should I just implement a DOT matrix driver and develop a circuit to monitor the condition of the battery? But if i were to implement a PIC microcontroller, what are the features can I include in it? Any suggestions? Please?

You could easily do it with a PIC - use one with inbuilt A2D, and use an external reference voltage (like in my tutorial). Depending how many LED's you require, you could use an 8 pin one (12F675) giving four LED's, or an 18 pin one (16F819) giving up to 14 LED's.

Using a PIC for this gives many advantages, for example a non-linear scale (if required), and a scale that doesn't start at zero - with a 12V battery you only need something like 10V to 15V range - you can easily adjust the PIC software for whatever range you want. If you plot the discharge curves for the battery you can decide at what exact points you want the different LED's to light - and this isn't likely to be on a linear scale!.

Funnily enough I was playing with PIC LED meter's a while back, I programmed one to replace the usual LM3914/5 designs - using a 16F876 it provided two 16 LED columns, switchable via a single pin to either a log or linear scale, another pin selected either dot or column mode.

 

[devonsc]

Thanks for that idea! Hope you dont mind giving me ur opinion about the following:

I was thinking to increase a lil of my budget and get a backlight LCD for the monitoring portion. Will this be very troublesome? Frankly, I've not touch PIC microcontroller before.

I'm now in ur tutorial page..thanks

 

[devonsc]

Real sorry for asking the following:

Can I perform some calculations and have the PIC microcontroller to display the following details through the LCD?

a.) Percentage or level of battery at the moment.
b.) Approximate life-span of the battery under the current specific load.

 

[Nigel Goodwin]

Real sorry for asking the following:

Can I perform some calculations and have the PIC microcontroller to display the following details through the LCD?

a.) Percentage or level of battery at the moment.
b.) Approximate life-span of the battery under the current specific load.

Yes, you could do all that - for b) you would have to monitor the current as well as the voltage, then you could always display the current consumption on the LCD as well.

 

[devonsc]

Thanks...

Nigel? I think I'm not suppose to ask this but do you mind letting me know the exact PIC that I should use if the functions that I intend to have in the LCD (16x2) are:

a.) Load current
b.) Approximate battery life
c.) Battery level

Real sorry if Im not suppose to ask such direct question.

 

[devonsc]

Hi there, I get what you mean regarding how difficult as well as dangerous it is to build switch mode power supply.

But, if I still intend to build one, a 240V AC to a 12V DC switching regulator (to an appropriate level for charging), do you mind guiding me?

It's okay if you're busy

 

[williB]

Thanks for that idea! Hope you dont mind giving me ur opinion about the following:

I was thinking to increase a lil of my budget and get a backlight LCD for the monitoring portion. Will this be very troublesome? Frankly, I've not touch PIC microcontroller before.

I'm now in ur tutorial page..thanks

when is this project due ?

 

[devonsc]

Approximately 2 months time, it dues on end of January. Do you think that a blur-newbie like me can make it?

I've not started much, the previous circuitry that I came out with are all linear regulators and I'm now suppose to implement switching regulators. In other words, the previous prepared circuits cannot be used. I need to try my best and learn up to improve the efficiency. :cry:

Really hope you dont mind guiding me all the way...Help needed.....Please?

 

[williB]

do yourself a favor and order your Pics TODAY .
order 2 16F648A has on board A/D converter
and 2 16F84A Just to get you going and is less confusing..
and another F648 if you like..

 

[Nigel Goodwin]

and 2 16F84A Just to get you going and is less confusing..

DON'T order 16F84's, these have been obselete for some time, order it's modern replacement the 16F628 - better spec and cheaper!.

 

[devonsc]

do yourself a favor and order your Pics TODAY .
order 2 16F648A has on board A/D converter
and 2 16F84A Just to get you going and is less confusing..
and another F648 if you like..

Huh? Do I really need that much? I thought I only need one to control the LCD for the monitoring portion?

Nway, I will take ur advice but I think I will buy one of each, issit okay? Hope you don't mind, me, as a student, I don't have much to spend. So I will get one 16F648A and 16F84A?

Thanks!

 

[devonsc]

Alrite, correction, I will now order one 16F648A as well as one 16F628?

Thanks for the advice...

 

[williB]

Alrite, correction, I will now order one 16F648A as well as one 16F628?

Thanks for the advice...

they are free , silly..

 

[devonsc]

Huh? What is free? You mean the PIC? Can be rite? I'm lost ???

 

[williB]

and 2 16F84A Just to get you going and is less confusing..

DON'T order 16F84's, these have been obselete for some time, order it's modern replacement the 16F628 - better spec and cheaper!.

true but thats what i started on , and that was complicated enough..

 

[williB]

Huh? What is free? You mean the PIC? Can be rite? I'm lost ???

YES order SAMPLES...

 

[devonsc]

Whaow! You mean I can do that? But how? As in from who? Or which company? Sorry for my blur question.

I was thinking to purchase them from Farnell. (heard of this company?) Any advice on how can I get free samples? I'm from Malaysia.

 

[williB]

thats ok i think mine came from Taiwan..
ok go to
www.microchip.com
top left search .. type in 16F628A
then click on the 628A
next screen right under spec sheet click on samples
Sorry about the extra dots on the link

 

[devonsc]

Oh no.....I'm from Malaysia and it states that its one of the country where they wont send the samples to

I'll go buy them then. Thanks!