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LDmicro Forum - multiplier |
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multiplier (by Zoran)
I have to multiply pulses from pic by two or four to have more speed for step motor.
Any suggestions.
(no subject) (by Ziggy)
try one shot rising and one shot falling to generate a pair of pulses on each edge.
Feed the pulses into yet another edge detection scheme as above to get the x4 times the pulse density. Poz
(no subject) (by Zoran)
Poz,
Do you have any schematics for it, to use transistors or IC if You have schematics with IC it would be better. Thanks,
(no subject) (by Ziggy)
Ah I see . If your Pic is working with LDmicro then just simply add the above solution to Your ladder logic.
If on the other hand You are looking for a hardware solution then You may consider using a hex CMOS Schmitt inverter with with some diode and Resistor capacitor pulse shaping to achieve outcome. What is the Pic doing? Poz(drav) Ziggy
(no subject) (by Zoran)
I tried like this but it doesn't work
(no subject) (by Ziggy)
Try like this...
The output will be a single pulse at each transition od input signal. Please use Schmitt inverters. The pulse width should be set to be approximately 50% duty cycle at highest input frequency. Pulse width is governed by RC time constant and the Schmitt trigger high trip point and low trip point. You can daisy chain this circuit for further multiplication of frequency but keep in mind that each successive stage pulse width will be limited to 50% duty cycle of maximum input frequency of that stage. I hope this helps Pozdrav
(no subject) (by Ziggy)
Rats,
forgot the attachment
(no subject) (by Zoran)
I tried some schematics from net and no luck.
Then I tried with one shot and it is working. I made multiplier with two,four and eight. Max output freq is 2.5kHz tested on 16F628A. Hvala Ziggy Pozdrav
(no subject) (by MGP)
It can not work because of the cycletime.
You can not multiply inside 1 cycletime, you need a delay. Make a counter at the end of your program and you will see that it does not work.
(no subject) (by Zoran)
I tested in real life with freq meter when input is 250Hz I have values which are very close 498Hz,998Hz and 1998Hz.
I simulate program with this file. Can this reCAPTCHA be more simple
(no subject) (by MGP)
Yes it works, strange I did the same thing and it did not work in the simulation, maybe I made an error.
To MGP (by Zoran)
Did You tested in real life?
(no subject) (by MGP)
No, I have no time, I am painting my house.
Now and then sometimes I look at the known forums with a beer in my hand ;)
(no subject) (by Ziggy)
Beer in hand..?
Better pay Picasso to paint the house.
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