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Andy Neil
02/01/06 00:39
Modified:
  02/01/06 01:43

Read: 1370 times
Basingstoke
Uk


 
#108860 - Description of the "Dispensing Unit"
Responding to: Suresh R's previous message
Suresh R said:
Kindly use the link given below to see the description this new thread.
http://www.8052.com/forumchat/read.phtml?id=108597

Since that description is buried in a whole load of other irrelevant stuff, here it is again:

Suresh R said:
I need some ideas to build a circuit that works as a despensing unit.
The operation of an existing unit is as follows:
The time(0 to 10 sec variable) is being set using a potentiometer arrangement.
then, when a button is pressed(push button) the solenoid connected to the despenser at the o/p will be 'ON' till the time set is elapsed.

I need to design a circuit for doing this operation.
can any one give me suggestions on selecting appropriate components that could be used to do this job.

could it be done using a micro.

The following points arise:

What are you dispensing?

Your scheme can only work if you are 100% sure that the dispensing mechanism is 100% repeatable and 100% linear.
How will you confirm that it has actually dispensed anything?

If this is a medical device, you certainly need more than just a 555!

You could certainly do this with a microcontroller - it's a simple timing project.
As Steve said, a small micro could be cheaper than an appropriate capacitor!
A micro would certainly be more accurate than a 555.

List of 57 messages in thread
TopicAuthorDate
Circuit for dispensing unit      Suresh R      01/31/06 05:09      
   1.1 sec monoshot      Abhishek Singh      01/31/06 09:43      
      this thread is apin off from an earlier      Terry Lingle      01/31/06 13:07      
         yes      Steve M. Taylor      01/31/06 13:55      
         timing circuit      Suresh R      02/01/06 04:17      
   Monostable      Andy Neil      01/31/06 12:08      
   Yes.      Steve M. Taylor      01/31/06 13:06      
   Hello All      Suresh R      01/31/06 22:23      
      Description of the "Dispensing Unit"      Andy Neil      02/01/06 00:39      
         using micro      Suresh R      02/02/06 00:25      
            Microcontroller      Andy Neil      02/02/06 01:35      
               Pressure      Steve M. Taylor      02/02/06 03:51      
            What must your circuit can do?      Kai Klaas      02/02/06 07:17      
               0.1 sec      Steve M. Taylor      02/02/06 10:34      
                  but not with a potentiometer      Erik Malund      02/02/06 10:38      
                     Vernier      Steve M. Taylor      02/02/06 13:02      
                        and calibrate it how?      Erik Malund      02/02/06 13:14      
               Precision        Andy Neil      02/02/06 15:13      
                  Sure!      Kai Klaas      02/02/06 16:01      
                     Price      Andy Neil      02/02/06 17:06      
                        Less than 1      Kai Klaas      02/02/06 20:02      
                           levels of precision      Suresh R      02/03/06 05:01      
                              Please have a look into datasheet!      Kai Klaas      02/03/06 05:57      
                                 somewhere here there is a link      Erik Malund      02/03/06 06:51      
                                    Details?      Kai Klaas      02/03/06 07:17      
                                       I recall that in an earlier thread      Erik Malund      02/03/06 07:20      
                              Ooops.      Steve M. Taylor      02/03/06 09:49      
                              Blown Discharge PIN      Abhishek Singh      02/04/06 19:15      
                                 You can also let the smoke out of the      Terry Lingle      02/04/06 22:37      
                                    limits      Steve M. Taylor      02/05/06 06:13      
                                       dissapation      Terry Lingle      02/05/06 09:45      
                                          There must be a point.      Steve M. Taylor      02/05/06 10:31      
                                             Fusing the bonding wires      Terry Lingle      02/05/06 13:59      
                                                History making      Steve M. Taylor      02/05/06 14:47      
                                                Current limiting      Kai Klaas      02/07/06 06:42      
                                 I do go through      Suresh R      02/07/06 01:50      
            schematic and code      Kai Klaas      02/05/06 19:47      
               codes      Suresh R      02/07/06 00:32      
                  Instruction Description      Andy Neil      02/07/06 04:28      
                     not quite      Erik Malund      02/07/06 06:09      
                        Pedantic      Andy Neil      02/07/06 07:12      
                           is that not the pot calling the kettle b      Erik Malund      02/07/06 07:17      
                              Of course not!      Andy Neil      02/07/06 07:31      
                  Answers      Kai Klaas      02/07/06 07:55      
                     Re: codes and shcematic      Suresh R      02/10/06 03:55      
                        Recommendations      Kai Klaas      02/10/06 07:05      
                           Decimal switches - how to start C      Erik Malund      02/10/06 08:09      
      LM555 pin 2 wired wrong.      Charles Bannister      02/01/06 04:45      
         ... and the LED?      Andy Neil      02/01/06 05:31      
            i'm sure thts not the circuit      Abhishek Singh      02/01/06 06:38      
            Astable??      Kai Klaas      02/01/06 11:46      
               I wondered who'd spot that first...      Andy Neil      02/01/06 12:47      
   Damaged?      Kai Klaas      02/01/06 11:51      
      And Andy's correction      Steve M. Taylor      02/01/06 12:03      
         Absolutely!      Kai Klaas      02/01/06 12:24      
   one shot in the foot      Erik Malund      02/01/06 12:31      
      Need not to work unreliably      Kai Klaas      02/02/06 07:10      

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