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I have completed buying all the things and made the setup .I have fixed all the connections as it is in the website but still now my robot is not working . I have bought n channel MOSFET enhancement type code:irf540n and diode 4007 type .but then also it is not working can you please help me in this project.
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The activity can be viewed at: Build a Motion-Activated Guard Robot (BlueBot Project #1)

Can u please tell me what is the problem in my project.

Hi,

The IRF510 is not a direct replacement for the MOSFET in our Bluebot kit. In particular it has a much higher gate threshold voltage, or the voltage required to turn the MOSFET "on." From the datasheet that range is 2-4V: https://media.digikey.com/pdf/Data%20Sh ... RF540N.pdf

The MOSFET in our kit is the STP16NF06L which has a lower gate threshold voltage of 1-2.5V:

https://www.jameco.com/z/STP16NF06L-STM ... 01373.html

https://www.jameco.com/Jameco/Products/ ... 001373.pdf

However, since the Bluebot is powered by a 6V (4xAA battery pack), it should still be possible to get it working with the IRF510. This is a complicated circuit and any errors in the wiring will prevent the robot from working. Most of the time when a user reports an issue, it turns out to be an error on the breadboard somewhere. If you can upload clear, in focus, well-lit photos of your breadboard from multiple angles so we can see all the wire connections, then we can help with debugging your circuit. If the photos are blurry or poorly lit and we cannot clearly see the connections then it will be difficult to help.

Thanks,

Ben