Can It Be this SIMPLE?

[sayzer]

First of all others,

It is very difficult to get 0 volt on the motor.

It might be done by short-circuit on the motor terminals but it is not safe for the motor. The motor life will be shorther then the life of a butterfly.

A powerfull resistor on terminals could be useful but again you will not get zero volt.

You may want to adjust that part a little by experimenting.




Word History: Is a butterfly named for the color of its excrement or because it was thought to steal butter? It is hard to imagine that anyone ever noticed the color of butterfly excrement or believed the insect capable of such theft. The first suggestion rests on the fact that an early Dutch name for the butterfly was boterschijte. The second is based on an old belief that the butterfly was really a larcenous witch in disguise.
How about that?

[Luciano]

Hi,

Wear a safety helmet!

With a full-face helmet or an helmet + protective chin cup
you will also provide protection to teeth.

Be careful!

Here the button "Go Faster" under the table was pressed!


* * *
What about using the PWM of the PIC?

Versatile DC Motor PWM Speed Controller:
(This example does not use a PIC to generate the PWM).

Part 1:
http://sound.westhost.com/appnotes/an009.htm
Part 2:
http://sound.westhost.com/appnotes/an009-2.htm

By using the PWM of the PIC you can set the right speed for the
child using the toy. (Next year you can set an higher speed).

This is done by changing the PWM duty cycle. By changing PWM duty
cycle you can set the motor to any speed and therefore create any
personalized acceleration curve.

(You will need a PIC with hardware PWM).

Best regards,

Luciano

[Melanie]

If I was a three-year-old, I'd want to experience the joys of burning rubber from a standing start... pass the 24v truck batteries... (then they can grow up and build drag-racers)...

Why bother with a PIC with the associated problems of Power Supply and Motor noise etc etc? Just a time-delay relay that enables operation of the turbo button a few seconds after power has been applied.

[Luciano]

..... experience the joys of burning rubber from a standing start...

I am not sure she would agree with you....


Luciano

[sayzer]

... (then they can grow up and build drag-racers)....

Why wait to grow up?

[f_lez]

If I was a three-year-old, I'd want to experience the joys of burning rubber from a standing start... pass the 24v truck batteries... .

My daughters 3 and a 1/2, her charger recently died, so I just swapped out the 6v batter for a 12v 17amphr one from a portable car starter, she's soon learned best way to set off is to stand up on it and lean forward........

she be in moto cross in a few years time I'm sure!