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Pulse Motor Micro Processor Controller Ver1.0

23/04/2007
After a lot of feedback from people I have scrapped this version for now and will be publishing Version 4 of the new Pulse Controller, but will leave these pages up for reference.

Overview

I have decided to work on and release public a pulse controller that uses a Micro Processor chip to control the timing and switching.
Most people use Reed switches for the timing but this can be fiddly when it comes to fine tuning the pulse timing, hopefully this circuit will allow people to have more control over this.

The circuit uses a Microchip Pic 16F876 to control the timing of switching upto 4 Mosfets (Connected to Electromagnets or anything else you want to pulse!)  and also 4 Opto Switches to detect the position of the rotor. I have attached the datasheets below, but you should be able to swap out the Mosfets for any you want to use as long as the Pin config suits.

Download Datasheet on the Mosfets.

Download Datasheet on the Optos.

The power for each Opto Switch is controlled via some PNP transistors, so you can choose to switch them off and hence pull less current if only using 1 Opto switch and 1 Coil output.

The Pic Processor is connected to a RS232 level converter chip that allows it to connect to the Serial Port of a computer and this will allow two things to be achieved.

1.) Download and program new Firmware into the Processor as new versions get released.

2.) Configure the timing and functions of how you would like the processor to act via a simple Windows program that downloads the config you want.

An example is , if you wanted to switch one Electromagnet on every time the first Opto Switch detects the position of the rotor and to pulse it the Electromagnet for one second, you would simply tell the Windows Software this is what you wanted and then it would download the config to the processor. If you wanted to add say a 10us delay after detection, again this can be downloaded, which will allow fine tuning of the pulse firing.

Another example you wanted to use 3 Opto Switches with one Electromagnet, this time the distance is measured from Opto Switch number one and Opto Switch two to get the speed that the rotor is running at  and this then determines the timing pause needed before the next pulse is applied on the Electromagnet.

Of course you could build a pulse motor with four coils and four Opto Switches, it will be up to you.

In version 2.0 I have now added a direct connection from the 4th Opto Switch that goes to the CTS Line of the Serial Port, this will allow feedback of a pulse without disturbing the Micro Processor when it is running the pulse routines. An example of what this can be used for is say a Rev Counter Application.
Also I have added a 20K Pot to the circuit that ill allow manual tweaking of the pulse delay while the routines are running.
 

10/03/2007