I tried my best to Google the information that I needed but I have a good understanding of the basic theory (I think). I have a book on order (MAKE: Electronics: Learning Through Discovery) and will be getting a breadboard but I would like to see if I am even on the right track with this project.
I have a device that I can turn on and off. Attached to the device is a powered USB hub (and hard drive). I have to unplug the hub's power when I am done with the device.
I would like to use a 5v power point on the device to help power down the HUB/drive. I would like to do this without a relay (if possible) so that I can fit it in the device's case. I would also like to use different wall warts to power the hub (in case the original one broke or was lost). I have a handle on that part (project box with voltage regulator + reverse polarity protection, power plugs, etc.).
From my research I would need a NPN BJT transistor, or a N-channel mosfet, or a logic-level mosfet.
I stopped by R. Shack and found a IRF510 mosfet but after researching I found someone who had problems because he was trying to switch power using 5v which was to low to 'fully open the gate'. I am trying to figure out the basics but I can not find a guide on syntax such as Vdss and Vgs (th) and others and how they relate to each other. I also found a 2N4401, a MPF102, and a TIP31 transistor at the same place but it would appear that either the power that I may need is too low or the 5v 'gate' is not strong enough. At least for what I found.
My simple need is that I want to disconnect/connect the power that I have to the hub via the device's power switch.
I figure that I would not realistically need more that 1 amp of power (if that) at 5 volts. I read about transistor voltage drop/loss and I can easily add a voltage regulated box inline between that wart (or any unregulated wall wart 1-2amps -- 5-12v). If the voltage drop is about .7v then it may be helpful to use an adjustable voltage regulator and send power in at 5.7v or so to help compensate for this loss. Is that foolish?
Pictures below may help. First one shows my setup now. Second picture shows what I would like to do at a minimum. The third shows what I would like to do as a complete project. The fourth shows you what I am thinking inside my head. Good or bad.
These are just simple pictures that are logical to me. Will a setup like this work? I know I need to add resistors and maybe a diode or two but I need to get my fundamentals down with the right device first. (Digi-Key is who I used before so any specific recommendations will be GREATLY appreciated). The transistor in the forth picture is not labeled because the different types of transistors have different pin-outs. If you have a specific transistor in mind then feel free (of course) to modify the picture to your suggestion.
BTW: this video helped me belive that this was possible: http://www.youtube.com/watch?v=Te5YYVZiOKs
1. My setup now
2. What I would like to do at a minimum.
3. what I would like to do as a complete project.
4. What I am thinking (basic_no resistors, etc. in place)
Thank you for any help and clarification that you can provide!
EDIT: I can work with any package type although I prefer thru-hole types but any type will do.
I have a device that I can turn on and off. Attached to the device is a powered USB hub (and hard drive). I have to unplug the hub's power when I am done with the device.
I would like to use a 5v power point on the device to help power down the HUB/drive. I would like to do this without a relay (if possible) so that I can fit it in the device's case. I would also like to use different wall warts to power the hub (in case the original one broke or was lost). I have a handle on that part (project box with voltage regulator + reverse polarity protection, power plugs, etc.).
From my research I would need a NPN BJT transistor, or a N-channel mosfet, or a logic-level mosfet.
I stopped by R. Shack and found a IRF510 mosfet but after researching I found someone who had problems because he was trying to switch power using 5v which was to low to 'fully open the gate'. I am trying to figure out the basics but I can not find a guide on syntax such as Vdss and Vgs (th) and others and how they relate to each other. I also found a 2N4401, a MPF102, and a TIP31 transistor at the same place but it would appear that either the power that I may need is too low or the 5v 'gate' is not strong enough. At least for what I found.
My simple need is that I want to disconnect/connect the power that I have to the hub via the device's power switch.
I figure that I would not realistically need more that 1 amp of power (if that) at 5 volts. I read about transistor voltage drop/loss and I can easily add a voltage regulated box inline between that wart (or any unregulated wall wart 1-2amps -- 5-12v). If the voltage drop is about .7v then it may be helpful to use an adjustable voltage regulator and send power in at 5.7v or so to help compensate for this loss. Is that foolish?
Pictures below may help. First one shows my setup now. Second picture shows what I would like to do at a minimum. The third shows what I would like to do as a complete project. The fourth shows you what I am thinking inside my head. Good or bad.
These are just simple pictures that are logical to me. Will a setup like this work? I know I need to add resistors and maybe a diode or two but I need to get my fundamentals down with the right device first. (Digi-Key is who I used before so any specific recommendations will be GREATLY appreciated). The transistor in the forth picture is not labeled because the different types of transistors have different pin-outs. If you have a specific transistor in mind then feel free (of course) to modify the picture to your suggestion.
BTW: this video helped me belive that this was possible: http://www.youtube.com/watch?v=Te5YYVZiOKs
1. My setup now
2. What I would like to do at a minimum.
3. what I would like to do as a complete project.
4. What I am thinking (basic_no resistors, etc. in place)
Thank you for any help and clarification that you can provide!
EDIT: I can work with any package type although I prefer thru-hole types but any type will do.
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