Hi Hi,
Just wondering is it possible to hook up one motor(with no supply) to another motor(which is turning and have its on supply) to generate voltage?
Hi Hi,
Just wondering is it possible to hook up one motor(with no supply) to another motor(which is turning and have its on supply) to generate voltage?
Yes, it was a very common procedure many years ago, known as a motor/generator set. During WW2 they were used extensively to power valve radio systems. I seem to recall that aircraft systems commonly worked off 400Hz supplies?, presumably generated in that way?.
Obviously, as with everything, you make a fair loss though, you only recover a portion of the energy driving the motor. I've no idea what the efficiency is like, it's far too long ago even for me :lol:
In recent decades they have been replaced by inverters, far more efficient, quieter, and cheaper.
my motor power supply is 12V. I am of thinking of sending the speed readings from the PIC to the PC. 12V seem to high to enter the ADC channel. thats was why i was considering the motor/generator.
my motor power supply is 12V. I am of thinking of sending the speed readings from the PIC to the PC. 12V seem to high to enter the ADC channel. thats was why i was considering the motor/generator.
Right! - so you're wanting to measure the speed of an existing motor!.
As you've already suggested, you could use a DC motor mechanically coupled, and this will give avoltage ouput proportional to the speed - but it's rather a complicated way to do it.
An easier way is to generate a pulse (or number of pulses) per revolution, you can do this with a slotted disk and opto-sensors, a disk with small mirrors and a refective opto-sensor, with a magnet and hall effect devices. There are many different ways!.
VCR's often do this in number of places!.
You simply use the PIC to measure the time between pulses, then you can calculate the speed with simple maths.
my motor power supply is 12V. I am of thinking of sending the speed readings from the PIC to the PC. 12V seem to high to enter the ADC channel. thats was why i was considering the motor/generator.
There are various ways, for a start you can use a simple software loop to count the interval (which is what my IR tutorial receiver does), or you can use the timers in various ways, or interrupts on change on PortB.
There's an old application note at MicroChip for a 50MHz auto-ranging frequency counter - at high frequencies it counts the pulses, at low frequencies it measures the pulse width.
You might be interested to know that STAMP BASIC (and most PIC BASIC's) have a "pulse in" command to measure the width of a pulse.
since im still a beginner, i just want to confirm whether my optocoupler circuit is ok. Everytime when the optosensor is blocked, the output to the PIC would be LOW. When it is unblocked, the output would be HIGH.
Apart from that, im just want to make sure my concept is right right for PIC counter. First of all, i will write a program whether the PIC will continous check the PORT pin to see whether is it HIGH or LOW every 0.1ms (in other words, 0.1ms is my sampling time). If it is LOW, then i will increment 1 into a variable register. Once it detects it is HIGH, then the data inside the variable register would be transmitted to the PC and convert it into RPM using the equation Nigel recommmended above.
Is the concept right :?: