acceleration and deceleration control by programming to 0 to 10volt(by faisal)
anyone helps me
Sun Nov 7 2010, 11:33:28, download attachment DISPLAY.doc
(no subject)(by Jonathan Westhues)
The speed of your output seems to be pretty slow (ramping up in 1 to 120 seconds, if I understand correctly). So you probably can use the PWM output of a PIC or AVR as your DAC.
So you could set the duty cycle of that PWM output proportional to the desired output voltage. For example, a duty cycle of 0 would correspond to 0 V, of 50% to 5 V, and of 100% to 10 V.
Then, you'd smooth the output waveform with an RC first-order low-pass filter. For example, to get your desired ~7 bits of resolution on a PIC16 with a 20 MHz crystal, you would need to set the PWM frequency to (20 MHz)/(4*128) ~ 40 kHz. So with a filter time constant around 500 ms (for example, R = 510k and C = 1u), the remaining ripple will be very small. A faster (smaller) RC time constant means that the output will respond more quickly to changes in the programmed duty cycle, but it also increases the ripple.
That gives you a voltage that goes between 0 V and the PIC's supply voltage as the PWM duty cycle goes from 0 to 100%. So if that voltage is 5 V, then you can use an amplifier with gain 2 V/V, running from a supply voltage of at least 10 V. You might, for example, use a TLV2371IP, which runs with Vdd up to 16 V, and can usefully deliver perhaps 10 mA of output current.
Then it's just a question of writing the program to set the duty cycle according to the waveforms that you want.
Sun Nov 7 2010, 13:42:28
THANKS A LOT MR.Jonathan Westhues(by FAISAL)
THANKS TO REPLY Jonathan Westhues
I WANT TO CREATE PROGRAMMING CONTROL PMW 0 to 100% duty cycle
by rampup and rampdown by programing but i select desire value of duty cycle if i select 10% duty cycle ramp time work in select 10%
you beter understand by attachment i need ldmicro file
i can not develop this program my self therefore i am not expert
in ldmicro calculation programming
i need help from you how to make this program please help me