For a science project, I am building a battery operated electric vehicle. Its not a big vehicle just about 3 feet long and about a foot wide. I have got most things covered except one. I need a way to buy/build a switch in the circuitry that cuts off the battery power after a certain time. The aim is to make the car travel a certain distance/time and then stop. What is the best and easy way to build a switch that will operate under these conditions? I have a motor powered by a battery pack and I need this switch in the circuitry so that it can shut power off after a programmed time.
Thanks for taking the time to look at this.
2007-12-23 06:11:49 · 2 answers · asked by newlex 2 in Science & Mathematics ➔ Engineering
If somewhere in the gear train driving the wheels there is a gear that turns only once in that travel distance you could put a cam on that gear axle and use the cam to trigger a switch.
Alternatively you could have a string that is wound up by the turning of the driven axle. When it is fully wound it could pull the handle on a toggle switch for the shutoff.
2007-12-23 06:21:08 · answer #1 · answered by Rich Z 7 · 0⤊ 0⤋
There are many ways to accomplish this. One way would be to use a 555 timer in a "one shot" fashion. Most any datasheet for a 555 will describe exactly how to do this, and how to calculate the required resistances and capacitance necessary for the selected time. You can have the output of the one-shot drive a transistor that cuts off power to the motor when the time elapses.
2007-12-23 08:12:44 · answer #2 · answered by Anonymous · 0⤊ 0⤋