This Forum is Dedicated For all The Object Oriented PIC Lovers .......... The concept behind OOPic is straight forward. Use preprogrammed multitasking Objects from a library of highly optimized Objects to do all the work of interacting with the hardware. Then write small scripts in Basic, C, or Java syntax styles to control the Objects. During operation, the Objects run continuously and simultaneously in the background while the scripts run in the foreground telling the objects what to do.

Sunday, November 25, 2007

Re: [oopic] H-Bridge issue...maybe.

Ok, I took a look at the voltage coming from the OOPic at various speed
settings. The voltage dropped steadily down to below 1V on the analog meter
at a value around 70.

However, I also went looking at the motor specs. The no load draw is 300 mA,
but the max draw at shaft lockup is 2A. I would have thought there was less
current draw at lower voltage, but I may be getting that wrong. In any
event, the 1A limit is being doubled.


rtstofer wrote:
>
> You should still check the output voltage on IOLines 17 & 18 without
> the H-Bridge. As the pulse width varies, the voltage should change.
> As I pointed out earlier, an analog meter will do the integration of
> the pulse width. A digital meter may not. If not, you need that 220
> ohm resistor in series with a 1 ufd capacitor between the pin and
> ground to form an integrator. Anything close from Radio Shack should
> work fine.
>
> One other thing: You never did say how much current your motors may
> require. Remember, the 754410 is limited to 1A per motor. That's a
> VERY SMALL motor. It is possible that the stall current (before the
> motor gets running) is so high that the driver shuts down on overcurrent.
>
> The ABSOLUTE MAXIMUM Continuous Output Current is 1.1A.
>
> So, connect your motors directly to the battery and measure the
> current. Measure as you try to stall the motor by loading it up.
>
> One amp is a VERY SMALL motor.
>
> Richard
>
>
>
>
>

--
View this message in context: http://www.nabble.com/H-Bridge-issue...maybe.-tf4867316.html#a13942338
Sent from the OOPic mailing list archive at Nabble.com.


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