Motor controller needed
 

I have an electronic project I am working on and need some help. My
Father-in-law gave me a broken electric scooter so I could convert it into a
toy for my son. It is very similar to this item:

http://cgi.ebay.com/ws/eBayISAPI.dll...1373 232&rd=1

The only thing wrong with this scooter was the electric motor control
circuit was faulty (everything else has been tested and works great).
Unfortunately he threw away the circuit and I am looking for a replacement.
What would I need to power a scooter of this size? Links to web sites or
ebay auctions would be greatly appreciated.

Thanks,
Bob

"Robert Wolcott" wrote in message
...
I have an electronic project I am working on and need some help. My
Father-in-law gave me a broken electric scooter so I could convert it into
a
toy for my son. It is very similar to this item:


http://cgi.ebay.com/ws/eBayISAPI.dll...1373 232&rd=1

The only thing wrong with this scooter was the electric motor control
circuit was faulty (everything else has been tested and works great).
Unfortunately he threw away the circuit and I am looking for a
replacement.
What would I need to power a scooter of this size? Links to web sites or
ebay auctions would be greatly appreciated.

Thanks,
Bob



Measure the current the motor draws under load, or just look at the fuse if
it's still around. Assuming it's just a DC motor, you can easily get a power
MOSFET that will handle the load, then drive it with a PWM circuit, there's
ready made chips to do this, or you can do it with the ubiquitous 555 IC.
The whole circuit should cost around 20 bucks.

"Robert Wolcott" wrote in message
...
| I have an electronic project I am working on and need some help. My
| Father-in-law gave me a broken electric scooter so I could convert it into
a
| toy for my son. It is very similar to this item:
|
|
http://cgi.ebay.com/ws/eBayISAPI.dll...1373 232&rd=1
|
| The only thing wrong with this scooter was the electric motor control
| circuit was faulty (everything else has been tested and works great).
| Unfortunately he threw away the circuit and I am looking for a
replacement.
| What would I need to power a scooter of this size? Links to web sites or
| ebay auctions would be greatly appreciated.

What voltage batteries? I'd be inclined to look at chopper type DC control
systems. GE published some in the 60's that used a couple of SCRs to control
the speed.

N

The motors are controlled by two 12V gel cell batteries in series. The two
batteries combined are about the size of a car battery


"NSM" wrote in message
news:aPvvd.23288$U47.22779@clgrps12...

"Robert Wolcott" wrote in message
...
| I have an electronic project I am working on and need some help. My
| Father-in-law gave me a broken electric scooter so I could convert it
into
a
| toy for my son. It is very similar to this item:
|
|
http://cgi.ebay.com/ws/eBayISAPI.dll...1373 232&rd=1
|
| The only thing wrong with this scooter was the electric motor control
| circuit was faulty (everything else has been tested and works great).
| Unfortunately he threw away the circuit and I am looking for a
replacement.
| What would I need to power a scooter of this size? Links to web sites
or
| ebay auctions would be greatly appreciated.

What voltage batteries? I'd be inclined to look at chopper type DC control
systems. GE published some in the 60's that used a couple of SCRs to
control
the speed.

N

"Robert Wolcott" wrote in message
...
I have an electronic project I am working on and need some help. My
Father-in-law gave me a broken electric scooter so I could convert it into
a
toy for my son. It is very similar to this item:


http://cgi.ebay.com/ws/eBayISAPI.dll...m=5541373 232
&rd=1

The only thing wrong with this scooter was the electric motor control
circuit was faulty (everything else has been tested and works great).
Unfortunately he threw away the circuit and I am looking for a
replacement.
What would I need to power a scooter of this size? Links to web sites or
ebay auctions would be greatly appreciated.

Thanks,
Bob



Oatley Electronics are selling them for $24 (aust $).
http://www.oatleyelectronics.com/

--
Regards ..... Rheilly Phoull

"NSM" wrote: "Robert Wolcott" wrote:

}| I have an electronic project I am working on and need some help. My
}| Father-in-law gave me a broken electric scooter so I could convert it into
}a
}| toy for my son. It is very similar to this item:
}|
}|
}http://cgi.ebay.com/ws/eBayISAPI.dll...1373 232&rd=1
}|
}| The only thing wrong with this scooter was the electric motor control
}| circuit was faulty (everything else has been tested and works great).
}| Unfortunately he threw away the circuit and I am looking for a
}replacement.
}| What would I need to power a scooter of this size? Links to web sites or
}| ebay auctions would be greatly appreciated.
}
}What voltage batteries? I'd be inclined to look at chopper type DC control
}systems. GE published some in the 60's that used a couple of SCRs to control
}the speed.

SCRs??? In a DC circuit??? How could a circuit drive the voltage to
zero in order to get the SCRs to stop conducting? Or has someone invented
an AC battery while I was asleep?

Stan.

"NSM" wrote in message
news:aPvvd.23288$U47.22779@clgrps12...

"Robert Wolcott" wrote in message
...
| I have an electronic project I am working on and need some help. My
| Father-in-law gave me a broken electric scooter so I could convert it
into
a
| toy for my son. It is very similar to this item:
|
|

http://cgi.ebay.com/ws/eBayISAPI.dll...1373 232&rd=1
|
| The only thing wrong with this scooter was the electric motor control
| circuit was faulty (everything else has been tested and works great).
| Unfortunately he threw away the circuit and I am looking for a
replacement.
| What would I need to power a scooter of this size? Links to web sites
or
| ebay auctions would be greatly appreciated.

What voltage batteries? I'd be inclined to look at chopper type DC control
systems. GE published some in the 60's that used a couple of SCRs to
control
the speed.

N



Why use a 1960's design? There's plenty of modern and readily available
circuits, just do a google search for PWM dc motor controller, size the
MOSFET appropriately for the load.

"Stan" wrote in message
...
"NSM" wrote: "Robert Wolcott"
wrote:

}| I have an electronic project I am working on and need some help. My
}| Father-in-law gave me a broken electric scooter so I could convert it
into
}a
}| toy for my son. It is very similar to this item:
}|
}|
}http://cgi.ebay.com/ws/eBayISAPI.dll...3&item=5541373
232&rd=1
}|
}| The only thing wrong with this scooter was the electric motor control
}| circuit was faulty (everything else has been tested and works great).
}| Unfortunately he threw away the circuit and I am looking for a
}replacement.
}| What would I need to power a scooter of this size? Links to web sites
or
}| ebay auctions would be greatly appreciated.
}
}What voltage batteries? I'd be inclined to look at chopper type DC
control
}systems. GE published some in the 60's that used a couple of SCRs to
control
}the speed.

SCRs??? In a DC circuit??? How could a circuit drive the voltage to
zero in order to get the SCRs to stop conducting? Or has someone invented
an AC battery while I was asleep?

Stan.

I played with SCR's controlling DC motors at one point, some motors have
enough commutator hash to cause the SCR to turn off but it's not reliable.

"Stan" wrote in message
...
| "NSM" wrote: "Robert Wolcott"
wrote:
....
| }What voltage batteries? I'd be inclined to look at chopper type DC
control
| }systems. GE published some in the 60's that used a couple of SCRs to
control
| }the speed.
|
| SCRs??? In a DC circuit??? How could a circuit drive the voltage to
| zero in order to get the SCRs to stop conducting? Or has someone invented
| an AC battery while I was asleep?

Nope! IIRC, you use a timing circuit to fire one SCR to turn battery current
on. Then, to turn it off, you fire a second one in parallel with the first
but into a capacitor. This shunts out the first which turns off, then the
second one turns off when the cap is charged. Track down an SCR manual from
GE in the 60's or 70's and you'll see the circuit. I believe it was designed
for electric golf carts.

NM

"James Sweet" wrote in message
news:9IGvd.3701$Z%1.1854@trnddc03...

| Why use a 1960's design? There's plenty of modern and readily available
| circuits, just do a google search for PWM dc motor controller, size the
| MOSFET appropriately for the load.

Or buy the module.

N