Re: It smells and i burnt my finger.

Lets see what went wrong... I have a 5 volt regulator, its a 7805a, 3 pings,

> left to right input ground output. on the input I put the - side of a 9 > volt battery. The ground goes back to the battery on the plus, and the > output wasnt plugged in. It started to smell like burning electronics, so I > removed the ground from touching the + of the battery. Touching the > regulator, i burnt myfinger. Am i missing something, why did it do this? All > i want to do is have 5 volts so i can mess with my new found stepper moter.

Get a new one. Put the + of the battery on the input, and the - of the battery on the ground.

-- Bye, Ray

formatting link
robot, walker and I-Cybie

Reply to
Ray
Loading thread data ...

Reply to
Kolie Kay

A stepper motor won't work with DC. It'll just sit there and heat up.

You need a stepper motor control IC to produce the pulsed control signals to drive it properly. This is one of the reasons I don't tend to use them.

Tom

Reply to
Tom McEwan

One thing to remember is that the 7805 is a linear regulator. This means that it is trying to supply voltage and current regardless of whether or not your circuit (load) is drawing anything. If you don't hook up a load, it will still heat up somewhat.

That said, when the 7805 and other similar members (7812, etc.) break down, they get extremely hot and do not regulate voltage at all in many cases. Chances are you probably did burn it partially out by some means or another.

As far as Steppers using DC current. Yes they do. A stepper has two functions: (1) move a determined amount when the phase changes and (2) remain locked when the phases do not change. I think the earlier post was assuming you did not want to ever remain in the locked position, but that is one of the nice attributes of a stepper. If you want to move the stepper, you will most certainly have to use some sort of arrangement to move it around. Darlington transistors work well as do MosFets. In Gordon's book(s) he has several examples of how do to this and control the direction via CMOS/TLL logic. With respect to Gordon, these examples are by no means the only way to do it. You could do it with relays; not very clean or elegant, but they will not heat up as much as the transistors.

Perhaps an acceptable approach would be to get a stepper controller chip (or make your own circuit using std logic parts) and then beef up the outputs to match your requirements.

-Kip Mussatt

electronics,

Reply to
K Mussatt

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.