![]() On the RaspberryPi.SE it was suggested that one can use MOSFET BS170 to switch a USB device on and off by a GPIO pin (3.3V). Simulate this circuit – Schematic created using CircuitLab I cut the power wire of the USB cable, and connected the MOSFET to it in the following way: I need to get 500mA to power a GSM dongle the voltage drop should preferrably be minimal since USB is quite strict on voltage). The official gate voltage is 3V and I supplied 3.3V to it.According to a scheme on RPi's elinux page, I should have cut the GND wire instead of the PWR one.I'm not sure that the two grounds are actually connected.(I use a speaker in the schematic to represent my USB device, and a switch to represent a pin of the GPIO.) ![]() I think I demaged the transistor I bought. ![]() I can buy a new one (even couple of them, they're really cheap), but I would prefer to know what to do before I experiment again or cut some more wires. The Internet Service Database is a comprehensive public IP address database that combines IP address range, IP owner, service port number, and IP security. I did some more search, and I found a schematic by bretth on, which seems to do what I want, using a P-MOSFET instead of N-MOSFET. Is this schematic angood way to go? It is a problem that GPIO provides 3.3V and maximal V_GS is 3V for N-FET and (minus) 2.4V for P-FET?įollowing advice from Dave Tweed it is apparent that switching a USB load via the ground rail is not good so, what remains of this answer is all about choosing a mosfet and checking the appropriate graphs in the spec for the device. Usb network gate 6.2 code for mac os Usb network gate 6.2 code install To access USB over RDP you’ll only need to install USB Network Gate on your local computer (that will be Server module) and on a remote machine (client module).Just install USB Network Gate on both host and guest OS (Windows, Mac, or Linux doesn’t matter) and access USB devices connected to a host machine inside. In short, look at the graph of drain current versus drain-source voltage and choose a device that has the lowest volt drop for the gate voltage you are able to provide. In this particular case it's appropriate to use a p channel mosfet switching the positive rail to the load and to do this requires an NPN BJT to interface between the gpio and the mosfet's gate. You should have inserted the N channel mosfet in the ground wire to the load with source to ground and drain to the positive rail connected load. Also you need to put a resistor across the gate and source to leak away charge once the switch has open circuited. The gate-source pins are effectively a small capacitor with very little ability to drain away charge / voltage fed to them when the switch is closed. Try 10kohm or 100kohm.ĮDIT NOTE - originally the question showed an IRF530 in the circuitģ.3V may be a little too lightweight for the the MOSFET you've shown in the diagram. The IRF530 is a 100V rated device and it has quite a high gate-source threshold voltage (2V min to 4V max). This means at 3.3V it may be only just starting to turn the MOSFET on fully.
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