Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

I need help in designing a circuit

Status
Not open for further replies.

chefach

New Member
I am computerizing my house and i need for it the follow circuit:

discription of the circuit:
http://www.geocities.com/doom019/window.bmp

This circuit controls the window movement by a motor.

The circuit will work as ill explain:
1. The circuit will get signal from the compuer in line 1 or 4.
2. Then a relays will close and the motor will turn left if the signal is from
line 1, and right if the signal is from line 4.
3. The motor will keep turning untill it riches to micro switch (A or B).
4. If "A" is on then it send a signal to line 3 and to the computer, and
if "B" is on then there will be a signal on line 2 and to the computer,
that will stop the motor imidiatly, and send to the computer the
position of the window (left or right).

I think thw circuit will run on 5V and the motor will run on 9V or 12V and not with the same power source.


Thank you :)
 
Circuit description
Assume A is operated B is released. Thus 3 is low & 2 is high. The computer reads 2 & 3.
The computer applies a pulse to 1 to operate relay L.
The pulse should be about 30 ms. ie. long enough to operate the relay reliably.
L holds via B. The motor drives until B releases L. (B opens the hold path of L)

When the computer wants to reverse the motor, it applies the pulse to 4.
Thus R operates & holds via A and the motor drives until A releases R.

The motor switching contacts are designed to prevent a short circuit across Vm should both relays operate for some reason.
Note that Darlington transistors have about 1 Volt across CE when on. Thus V+ should be one Volt greater than the voltage required by the relay.

Len
 

Attachments

  • motor_control.gif
    motor_control.gif
    53.3 KB · Views: 887
if the window is open there can be a situation that neither one of A and B is close so it will still work?
 
chefach said:
if the window is open there can be a situation that neither one of A and B is close so it will still work?
That is the situation shown in the diagram. In that case, the computer can drive the motor either way.

chefach said:
Thank you very much.
You're welcome

Len
 
1 more question :)

How cant I stop the motor (trought the computer) if it didn't rich A or B?

Like if I dont want to close the windoe completly?
 
chefach said:
1 more question :)

How cant I stop the motor (trought the computer) if it didn't rich A or B?

Like if I dont want to close the windoe completly?
The circuit I posted does not allow for the computer to stop the motor. To do that you would have to modify the circuit.

One way to do it is to remove the holding paths to the relays and make the computer hold the relay. Another way would be to have another wire from the computer that is used as a "stop motor" wire.

Let me know if you need more help.

Len
 
i trying to make an project in my college it is about the remote control car if u can help me in making it i want it making in rf of with bluetooth technology
 
We don't mind helping you but we won't do all of the work for you. Please post what you've already done including any ideas you've had and we might be able to make some suggestions. If you've got completely no idea then may be it's your lecuturer's fault and it isn't right that you make him/her look good by cheating and copying from the Internet.
 
If you want to change directions, just swap any 2 of the three wires. If you want to control speed, go to the International Rectifier web site and get application note AN-985.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top