Today we’re going to use MOSFETs to make a phase light. For this project, we’re using two n7000s, which are n-channel MOSFETs. Connect with Karen on the element14 community: bit.ly/2SegofN
I try to keep circuits simple so it's easier to figure out what each component does within the circuit. With microcontrollers, it always feels like it's all in the programming.
When we power up the caps charge. Once they are charged the gate opens MOSFET. This makes the next cap to discharge. After this we go through a cycle of charging and discharging which makes FETs open and close and this makes the blinking effect?
As one mosfet gets turned on the next one downstream turns off because the one meg tied to the drain discharges the downsteam capacitor. Then the cycle repeats round and round. I think this is similar to a ring counter.
c1 will charge first and then as it discharges c2 or c3 will get charged and as say c2 charges and discharges c3 and c1 would try to charge and c3 should win as it had accumulated some. each capactior as its charges causes its mosfet led to light up.
RED needs 2.0V to make ON, GREEN need 2.2V to make ON, BLUE needs 3.5V to make ON. So, the 3 LEDs will not be same color. If they are same color, they will just blink at the same time. This is just manipulating their forward bias voltage.
Great circuit, thanks. The led turn off because when the next LED turns on, the capacitor discharges through its mosfet via the 1M resistor. The zener diode on the mosfet is just optional circuit protection?
Looking at the circuit I keep seeing first green turn on (lowest voltage drop over red led), then red then blue... Cant understand the red-green-blue though...
you need to add a 100 ohm resistor between the cap and the gate to prevent the fet from becoming an RF modulator due to the inductance of the source wire. The resistance works with the feedback and gate capacitance to lower the gain in the Mhz to Ghz range.
That would be true on a Bipolar Junction Transistor (which look similar and call the Gate a "base"). However, on the MOSFET, there is no flow of current through the gate - its triggered by voltage differential only; thus, the "field effect". There's discussion at the e14 link starting (bit.ly/2SegofN).
As someone down below mentioned, one of the LEDs is most likely to turn on initially, due to different characteristics of blue, green and red LEDS. The LED turns off when the capacitor is discharged through the FET to the left when it turns on. This discharging / charging effect “ripples” around the ring.
once the power has passed through the 3rd 1M resistor the voltage is too low. Change power supply to 9 volts DC IMPORTANT remember to change the values of the resistors located at you LEDs. I used 470 ohms to replace the 330 ohms. Set up 5 phase shifting circuit.
You're better off buying them from China, they are really cheap. Even if you could salvage them from a circuit, they wouldn't be usable on a breadboard or a protoboard.
You're hot , a beautiful voice, and you can actually build circuits I got to be dreaming anyways some reason RU-vid presented another one of your videos and I might build one if I see you do an electrolytic mic amp circuit (idk why that just seems to be my fascination right now)
