Hey everyone! Love the forum, I've been a lurker for a bit too long to be honest!
Anyways, my name is Stuart- I'm a technology student at the University of Glasgow. And like I'm sure a lot of you guys have done, I've recently started getting electronics lectures, tutorials etc. So I have a VERY basic knowledge but I'm eager to learn (hence joining).
I was actually wondering if anyone here could give me a hand with a project I'm working on just now, it should be REALLY simple for you guys looking at some of the depth that some things have gone into!
I'm currently designing a clock in my design class, and we have to make a working prototype of our model. The design that I have is basically a laser like >>**broken link removed**<< one which is on a unit on the ceiling which slowly turns, the time is then indicated by where the laser dot is pointing to on the wall.
The problem I have had is that clock mechanisms are very fragile, and dont have enough torque to turn the weight of the motor round. So I decided that a DC motor would be far better to do this. The problem I have however is that they turn severeal hundred revolutions per minute! Not the 0.08 revolutions per hour that I need it to do in order to tell the time! Now I know that if you half the voltage going into a stepper motor, it halfs the RPM. So could I just have a circuit containing only a power supply, a big enough resistor, and a motor and set the speed from that?
Because it is only a prototype, it does not need to extremely accurately be able to tell the time, however I cant have it spinning a laser round at 200rpm! I just need to slow it down enough to give our lecturer a picture in his head of how exactly the product would work.
Someone suggested a stepper motor to me, but are they not very expensive and do they not need to be computer programmed?
Thanks for reading guys, any help will be really appreciated!
Anyways, my name is Stuart- I'm a technology student at the University of Glasgow. And like I'm sure a lot of you guys have done, I've recently started getting electronics lectures, tutorials etc. So I have a VERY basic knowledge but I'm eager to learn (hence joining).
I was actually wondering if anyone here could give me a hand with a project I'm working on just now, it should be REALLY simple for you guys looking at some of the depth that some things have gone into!
I'm currently designing a clock in my design class, and we have to make a working prototype of our model. The design that I have is basically a laser like >>**broken link removed**<< one which is on a unit on the ceiling which slowly turns, the time is then indicated by where the laser dot is pointing to on the wall.
The problem I have had is that clock mechanisms are very fragile, and dont have enough torque to turn the weight of the motor round. So I decided that a DC motor would be far better to do this. The problem I have however is that they turn severeal hundred revolutions per minute! Not the 0.08 revolutions per hour that I need it to do in order to tell the time! Now I know that if you half the voltage going into a stepper motor, it halfs the RPM. So could I just have a circuit containing only a power supply, a big enough resistor, and a motor and set the speed from that?
Because it is only a prototype, it does not need to extremely accurately be able to tell the time, however I cant have it spinning a laser round at 200rpm! I just need to slow it down enough to give our lecturer a picture in his head of how exactly the product would work.
Someone suggested a stepper motor to me, but are they not very expensive and do they not need to be computer programmed?
Thanks for reading guys, any help will be really appreciated!