Hi everyone,
What I am wondering is if there is a way to convert 5 volts to 12 volts. The application I will be using this for is a USB driven motor. The USB cable can only handle 5 volts and the motor is 12 volts. So I am wondering if there is a device or something simple to build that can bridge the gap between the voltages. Thank you for your advice!
Sincerely
Chris
mgb_phys
Aug22-08, 10:55 PM
Look up dc-dc converter (or boost converter)
But remember that USB can only supply 500mA and the converter will waste some power
brewnog
Aug23-08, 10:15 AM
Summit, your USB cable isn't limited by voltage, but by current.
russ_watters
Aug23-08, 11:23 AM
...and therefore it is probably better to find a suitable 5V motor.
Summit07
Aug24-08, 01:58 AM
Thank you for the advice, much appreciated. Would the same apply if I replaced the USB cable with a Parallel port cable?
brewnog
Aug24-08, 04:18 AM
Yes the same would apply. The problem is nothing to do with the cable, but your understanding of electrics.
Depending on what you're trying to do (let us know!), I'd go forward with your USB idea with a suitable 5V motor, making sure that you're not going to exceed the relevant current limits.
NoTime
Aug25-08, 09:14 AM
Unlike USB, which has a designated power connection, Parallel Ports are not designed to provide any power.
Parallel Ports have only signal level outputs.
isly ilwott
Aug25-08, 09:48 AM
Unlike USB, which has a designated power connection, Parallel Ports are not designed to provide any power.
Parallel Ports have only signal level outputs.More information is required regarding the motor you are trying to drive. Simply describing it as a 12 volt motor is not sufficient. The kw rating, or horsepower rating, full load current rating is required to determine the power needed to run the motor. Can you describe the motor with more specificity?
I am thinking you may need a separate 12 volt power supply that allows for voltage driven input control.
Summit07
Aug25-08, 07:19 PM
Thank you again for the advice here are the technical specs of the motor.
HP: 1/10
RPM: 2300
Rotation: Reversible
Torque (oz-in): 40
Field Volts: 12
Diameter: 3in
Shaft Dimension (inches): 5/16 x 2
mgb_phys
Aug25-08, 07:28 PM
1/10 of a horsepower is 75W
At 12V that is 6.5A, USB can supply 5v at 500ma = 2.5W = 1/300 HP
I think you are slightly out of luck!
You could use a car battery to power the motor and a USB device to control a relay to turn it on/off.
Summit07
Aug25-08, 07:30 PM
I was crunching the numbers as well and came to that same conclusion. Back to the drawing board it seems...