Robot Efficiency & other Robot stuff - Electronic Circuits Projects Diagrams Free

williB · 7th October 2004, 02:31 AM

would it be possible to store the energy from the reverse EMF of a stepper, as it is running.
i was just wondering if i could save power in battery powered robot with a very large electrolytic capacitor connected across the main power supply.

Optikon · 8th October 2004, 04:28 PM

Quote:

Originally Posted by williB

would it be possible to store the energy from the reverse EMF of a stepper, as it is running.
i was just wondering if i could save power in battery powered robot with a very large electrolytic capacitor connected across the main power supply.

yes, one form of it is called regenerative braking. A capacitor across mains supply will not save any power. Capacitors just store energy.
To make the system effective, you will have to get that energy back into the battery. When the vehicle is moving but the drive is not driving the motors, the motors can act like generators and that energy can be recovered but it is more complicated than just using a capacitor.

williB · 8th October 2004, 05:21 PM

ok but when u turn off a coil in the stepper,, and redirect the back EMF with diodes twards the positive supply terminal,, where does it go..
i can only assume that it is stored in the powersupply caps..
so that is what i had in mind with the battery setup..

williB · 12th October 2004, 05:30 AM

Ive just got my robot moving for the first time..last night..
i am using two steppers ,one for each back wheel.
the two steppers are connected together..ie driven by the same drive transistors..i will drive them seperately after i get four more IRF 510's
i realized thet i had to run the second one in reverse so i made the proper connections
something very strange happened ..
When all power was off and i turned one wheel ..the other wheel turned in the same direction..!!
so i turned it the other way .. the other wheel turned in the other direction!!...hmm..sort of an electronic mini car differential

**Nigel Goodwin** · 12th October 2004, 06:07 AM

Quote:

Originally Posted by williB

Ive just got my robot moving for the first time..last night..
i am using two steppers ,one for each back wheel.
the two steppers are connected together..ie driven by the same drive transistors..i will drive them seperately after i get four more IRF 510's
i realized thet i had to run the second one in reverse so i made the proper connections
something very strange happened ..
When all power was off and i turned one wheel ..the other wheel turned in the same direction..!!
so i turned it the other way .. the other wheel turned in the other direction!!...hmm..sort of an electronic mini car differential

An electric motor works backwards as a generator, steppers do this as well as conventional motors - EPE did an article on a batteryless torch using a stepper motor the other year.

williB · 12th October 2004, 06:14 AM

i had a neighbor that called a flashlight a torch.
over here , a torch is what the croud was using to find Frankenstein at night.. :shock: :wink: :wink:

Optikon · 13th October 2004, 09:17 PM

Quote:

Originally Posted by williB

i had a neighbor that called a flashlight a torch.
over here , a torch is what the croud was using to find Frankenstein at night.. :shock: :wink: :wink:

yes... HA HA... I always smile when I see "torch".. Frankenstein is precisely the image that pops into my mind! LOL

williB · 14th October 2004, 12:31 AM

Quote:

Originally Posted by Optikon

Quote:

Originally Posted by williB

i had a neighbor that called a flashlight a torch.
over here , a torch is what the croud was using to find Frankenstein at night.. :shock: :wink: :wink:

yes... HA HA... I always smile when I see "torch".. Frankenstein is precisely the image that pops into my mind! LOL

Yeah mine too !! :lol: :lol:

**Nigel Goodwin** · 14th October 2004, 05:33 AM

Quote:

Originally Posted by williB

i had a neighbor that called a flashlight a torch.
over here , a torch is what the croud was using to find Frankenstein at night.. :shock: :wink: :wink:

The English are far too civilised for such primative thoughts :lol:

williB · 14th October 2004, 12:58 PM

Quote:

Originally Posted by Nigel Goodwin

Quote:

Originally Posted by williB

i had a neighbor that called a flashlight a torch.
over here , a torch is what the croud was using to find Frankenstein at night.. :shock: :wink: :wink:

The English are far too civilised for such primative thoughts :lol:

but are they good spellers :shock: :wink:

**Nigel Goodwin** · 14th October 2004, 01:50 PM

Quote:

Originally Posted by williB

but are they good spellers :shock: :wink:

Not me anyway 8)

williB · 15th October 2004, 01:46 AM

Nigel looky what i found while roaming around the net..

what i found particularly interresting was the Pic net USB page

http://www.alecmcnamara.freeserve.co...tusb/index.htm

could not an ambitious person devise a USB pic programmer with this info??

**Nigel Goodwin** · 15th October 2004, 05:44 AM

Quote:

Originally Posted by williB

Nigel looky what i found while roaming around the net..

what i found particularly interresting was the Pic net USB page

http://www.alecmcnamara.freeserve.co...tusb/index.htm

could not an ambitious person devise a USB pic programmer with this info??

Why not just use the details for the PICKit 1 on MicroChips website?, it gives the circuit, source code for the 745, and source code for the VB program to run on the PC.

Basically both the PICKit 1 and the PIC Net design use the code from the original 745 application note.

williB · 18th October 2004, 02:27 AM

I thought that i would show yall my robot car .

williB · 18th October 2004, 02:32 AM

this board takes the signals from the PC .. later on from the Pic..
and drives the steppers..

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7th October 2004, 02:31 AM	(permalink)
williB	Robot Efficiency & other Robot stuff would it be possible to store the energy from the reverse EMF of a stepper, as it is running. i was just wondering if i could save power in battery powered robot with a very large electrolytic capacitor connected across the main power supply.

8th October 2004, 05:21 PM	(permalink)
williB	ok but when u turn off a coil in the stepper,, and redirect the back EMF with diodes twards the positive supply terminal,, where does it go.. i can only assume that it is stored in the powersupply caps.. so that is what i had in mind with the battery setup..

12th October 2004, 05:30 AM	(permalink)
williB	Ive just got my robot moving for the first time..last night.. i am using two steppers ,one for each back wheel. the two steppers are connected together..ie driven by the same drive transistors..i will drive them seperately after i get four more IRF 510's i realized thet i had to run the second one in reverse so i made the proper connections something very strange happened .. When all power was off and i turned one wheel ..the other wheel turned in the same direction..!! so i turned it the other way .. the other wheel turned in the other direction!!...hmm..sort of an electronic mini car differential

12th October 2004, 06:14 AM	(permalink)
williB	i had a neighbor that called a flashlight a torch. over here , a torch is what the croud was using to find Frankenstein at night.. :shock: :wink: :wink:

15th October 2004, 01:46 AM	(permalink)
williB	Nigel looky what i found while roaming around the net.. what i found particularly interresting was the Pic net USB page http://www.alecmcnamara.freeserve.co...tusb/index.htm could not an ambitious person devise a USB pic programmer with this info??