Alright, so today I’m gonna walk you through this little project I did with a MOSFET as an inverter. It was a fun little dive into basic electronics, and I figured I’d share my journey – warts and all.
It all started with me just wanting to understand how inverters work at the component level. I mean, I knew the theory, but I wanted to see it in action, ya know? So, I grabbed a MOSFET (an N-channel one, specifically – a 2N7000, I think), a resistor, a breadboard, some wires, and a 5V power supply.
First, I looked up a schematic online – nothing fancy, just a basic MOSFET inverter circuit. Basically, you’ve got the MOSFET’s gate connected to your input signal (through a resistor, usually around 10k ohms), the drain connected to your positive voltage supply (5V in my case) through another resistor (the pull-up resistor, I used a 1k ohm one), and the source connected to ground.
Then came the fun part – putting it all together on the breadboard. I started by plugging in the MOSFET, making sure I knew which pin was which (gate, drain, source – datasheet is your friend!). Then, I connected the source to ground. Next, I ran a wire from the drain to one end of the 1k ohm resistor, and the other end of the resistor to the 5V rail on my breadboard.
After that, I connected the 10k ohm resistor between the input pin (where I’d be applying my 0V or 5V signal) and the gate of the MOSFET. This resistor is important – you don’t want to directly connect a voltage source to the gate!
Now, for the output. I simply connected a wire to the drain of the MOSFET – that’s where the inverted signal will be.
Time to test! I used a simple jumper wire to simulate the input signal. Touching the input (10k ohm resistor) to the 5V rail would be a HIGH signal, and leaving it disconnected (or connected to ground) would be a LOW signal. I used a multimeter to measure the voltage at the output (the drain of the MOSFET).
Here’s what I saw:
- When the input was HIGH (5V), the output was LOW (close to 0V). The MOSFET was turned ON, effectively shorting the output to ground through the drain-source channel.
- When the input was LOW (0V), the output was HIGH (close to 5V). The MOSFET was turned OFF, and the pull-up resistor pulled the output voltage up to 5V.
Voila! An inverter! Simple, but effective. It wasn’t perfect, of course. The output wasn’t exactly 0V or 5V – there was a little bit of voltage drop across the MOSFET when it was on, and the pull-up resistor created a voltage divider effect. But hey, it was close enough to prove the concept.
Lessons Learned:
- Datasheets are your best friend. Knowing the pinout of the MOSFET is crucial.
- Resistors are important for protecting components. Don’t skip ’em!
- Breadboarding is a great way to quickly prototype circuits, but keep the wires short and neat to avoid signal issues.
Next Steps:
I’m thinking about playing around with different resistor values to see how they affect the switching speed and voltage levels. Maybe even try using it to drive a simple LED circuit. Gotta keep experimenting!
Anyway, that’s my MOSFET inverter adventure. Hope it was helpful (or at least entertaining!). Go build something!