funnyqert.blogg.se - Arduino transistor gate not being grounded

#ARDUINO TRANSISTOR GATE NOT BEING GROUNDED HOW TO#
#ARDUINO TRANSISTOR GATE NOT BEING GROUNDED SERIES#

The emitter of Q1 and the source of Q2 are both connected to ground.The gate of Q2 is connected only to the collector of Q1, not to ground.RTC SQW is connected only to the base of Q1, not to VCC.Based on the function of the circuit, here are the actual connections: In your schematic, dots are used only to show some pin connections (which is wrong). The thickness of the lines shouldn't matter and is probably an artifact of converting the schematic to a PNG. Another way is to have one wire curve to the side to show an unconnected intersection. The normal way to show this is to have a dot at connected intersections. UPDATE: The intersections between wires are unclear - another way this schematic is poorly-drawn. For this reason, it's best to avoid millifarads and the mF abbreviation and just use microfarads. In old schematics, mF was used as an abbreviation for microfarads. Microfarads should always be written μF or uF. If they really meant 0.1 millifarads (100 microfarads), the capacitor is probably a bad attempt at keeping the Arduino running after its power is switched off. It's standard practice to have a 0.1 microfarad capacitor between a digital IC's power and ground pins to ensure a steady supply voltage during switching.

I'm not sure if the capacitors are really meant to be 0.1 millifarads or if they're the standard 0.1 microfarads. Switching an IC's ground connection is a bad idea for a number of reasons. When turned off, Q2 disconnects the ground, (theoretically) powering off the Arduino.

When turned on, Q2 connects the Arduino's ground pin to the circuit ground.

The inverted square wave is connected to the gate of Q2.

R3 and Q1 form a simple inverter that inverts the square wave output from the RTC.

The MOSFET is upside-down, and both the MOSFET source and the BJT emitter are connected to ground. I'm sure I have some basic misconceptions, hopefully the above is enough for y'all to help me identify them?Īlso, if y'all can help me identify the names of patterns used in this circuit, it'd help me.Īlso, ps, what tools might I use to simulate circuits like this one and learn on my own how/what/why? I'm aware of sparkfun's tutorials and some courses on udemy, but what are other go-tos?Įdit: related, Using a DS3231 RTC alarm + MOSFETS to turn on a MCUĪs the comments say, this circuit is terrible.

why is the npn emitter connected to mosfet collector?.

how is current flowing back from arduino ground to vcc ground?.

how does connecting the mosfet drain to arduino ground permit current to flow?.

I get that the RTC pin is turning on the npn transistor to allow current to flow, and that somehow that connects the arduino to ground, but I don't get how the grounding part works. Specifically, I don't understand the combination of the npn and the mosfet. I'm novice with electronics, so this might be a simple circuit. It uses an RTC to turn on an arduino, via a npn transistor and a mosfet. Example 0,7 mA fo a certain base-resistor then I will go up to drive the base with 2 mA just to make sure the transistor is fully conductantįor calculating I simply did a duckduckgo with duckduckgo.I'm trying to understand how the schematic from this github repo works. In most cases the base-current is in the range of less of 5 mA. Then I look on the base current how much is it?

Starting with a high resistance = very low current and then reducing the resistance until the needed current through Collector-Emitter is reached. Me personal I do not calculate these currents I measure them. When you press the button, the input goes HIGH, the output goes LOW. When the button isn’t pressed, the input is LOW and the output is HIGH, which causes the LED to light. For this electronics project, a normally open pushbutton is used as the input.

#ARDUINO TRANSISTOR GATE NOT BEING GROUNDED HOW TO#

You just have to make sure that the base-current is high enough to make the transistor fully conductant. This project shows how to assemble a simple transistor NOT gate on a solderless breadboard.

But not all datasheets the one for the BC327 is rather poor with diagrams.Īs you are just switching fully on fully off the value must not be calculated carefully. The datasheets of transistors provide diagrams for this.

This means through the base must flow a current of The base of the transistor needs a current limiting resistor

#ARDUINO TRANSISTOR GATE NOT BEING GROUNDED SERIES#

This means you need no extra resistor in series to the LED like shown in the schematic for a single LED This means the current-limiting resistors in series with the LEDs are inside the LED-strip.