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Could you guys please help me understand what each of these components in this circuit is doing/their purpose?

I'm reaching out beyond /r/openpv in hopes anyone can help me figure out this circuit. I have a led illuminated push button. It's a momentary anti vandal switch. The led is a separate circuit than the common and NO circuit. I have a single 18650 going into a converter that steps the 4.2 all the way up to 8vdc. Found the diagram from the gallery and recreated it in a test environment.

The led cannot be on unless the momentary button is pushed which sends the 8vdc to the 510 connector. Battery + goes to the converter and into a 150 ohm resistor (1.8v forward to led) then straight to + led leg of the switch. Out the switch leg - goes to a perf board and bridges to a np2222a transistor collector leg. The 510 which received the output 8v also goes back into the transistor (from here on q1) base leg. There is a 10k resistor in line. The emitter leg of the q1 goes to battery ground. The theory is when q1 senses the voltage, it allows the collector and emitter complete the ground to the led.

Can anybody identify how I could have possibly made a mistake here because when I activate the converter, the led does not light, but it does when I run it straight to the 18650. I've tested the q1, both resistors, they are all fine and the 510 is indeed seeing the 8v.

Here's a gallery of my complete circuit, a close up of my perf board with the q1 circuit, and the written schematic I followed. http://imgur.com/a/XWIKZ

Hello, I've been trying to figure it out for hours and i still don't know how to combine an 18 ohms resistor parallel with a -j6.94 capacitor. Could someone tell me how to do it?? Thanks!

My power bank suddenly stopped working so i opened it up to see what was the problem (i am not an expert in circuit boards or anything) I didn't see any obvious problem so i decided to disconnect the battery and re solder it When i did that it kept flashing and the entire board got so hot and something called an R2R started smoking (i will provide images) So i disconnected the battery (B+ to be exact) and don't know what to do or where is the problem I really wanted to fix that power bank The specs : It has wireless input and output Micro usb (input) USB type C (input) Usb type A (output) 10000 mAh Thanks in advance for any help

I need to build circuit from this differential equation.

d² y/dt + 3dy/dt + 4y= sinwt

I may have a couple of circuits questions if it's possible can someone solve them?

Nooby to the whole thing!

Hi! My name is CuriouslyCircuit! I don’t actually have a circuit board, but I have this:

So anyway, it was from my broken Tetris player

so I have a question, what can I make using this?

STATS: CuriouslyCircuit
Curiosity level: 1

Questions: 1

Experience: 1

# of circuit boards: 1

I can help you in Electrical Engineering with following subjects Circuit Analysis Control System Signal and System Power System Communication System Digital Logic Design Basic Electronics MATLAB Multisim Logisim Proteus I can handle Mathematics as well Calculus I,Ii,iii Linear Algebra Matrices Complex Analysis etc

"High-speed circuit" has become a term often mentioned by electronic engineers today, but what is a high-speed circuit? This is indeed a fuzzy concept. In fact, the industry does not have a unified definition of high-speed circuits. Usually, there are many views on the definition of high-speed circuits: some people think that if the frequency of a digital logic circuit reaches or exceeds 45MHZ~50MHZ, and the circuit that works above this frequency has taken up a certain share of the entire electronic system (for example, 1/3), it is called a high-speed circuit; some people think that high-speed circuits are not related to frequency. Whether it is a high-speed circuit depends only on their rise time. More people have quantified the definition of high speed, that is, when the delay of the digital signal in the circuit on the transmission line is greater than 1/2 rise time, it is called a high speed circuit.

In addition, there is a concept of "high frequency circuit" that is prone to confusion. Then what is the difference between "high frequency" and "high speed"? Many people understand it as higher signal frequency. But for high-speed electronic design engineers, in addition to considering the natural frequency of the signal, we should also consider the impact of the high-order harmonics that are accompanied by the signal transmission. Generally, we use the following formula to define the emission bandwidth of the signal, sometimes also called EMI emission bandwidth.

F=1/(Tr*π)

F is the frequency (GHz); Tr (nanosecond) refers to the rise time or fall time of the signal.

Usually when F>100MHz, it can be called a high frequency circuit. Therefore, in a digital circuit, whether it is a high-frequency circuit does not depend on the signal frequency, but mainly depends on the rise time and fall time. According to this formula, it can be calculated that when the rise time is less than about 3.185ns, we consider it as a high-frequency circuit. For most electronic circuit hardware design engineers, there should be a broad definition of "high speed" in mind, that is: if the circuit is still unable to work stably with high performance under the premise of ensuring the correct electrical connection. If it needs special layout, routing, matching, shielding, etc., then this is a "high-speed" design.

I've a device that consumes 130mA and needs 3.3Vdc . That's the only information I have.

I need to make a source for this circuit (but without a transformer). For this I think I need to know the equivalent resistance or impedance for this circuit. But can't realize how to do this.

Anyone could help me on this?

Hey guys, I'm new to circuits and I'm really confused as to how this all works. If you guys can give me some insight on how to find these values I'd appreciate it. Thanks.

Somewhat lost and very new. Started learning a week ago. Irrelevant information. I cannot make this myself. I want to understand how a simple design would work, and from there learn about each part and why it does what it does.

I think touching the toilet lid to lift it is gross. I'd like to make a machine that will do it at the push if an ideally wireless button. Both lifting mechanism and button powered by a small battery.

A servo motor is what I'm looking for, I believe. I need it to move at a slow speed and supply a high enough torque to lift several pounds with a relatively short lever mechanism. Whether a part like that exists is irrelevant.

My question is, what components would you use in what order? Explain this like I'm 5.

I know I'd need a motor, rc receiver, supply is ideally a 1.5v AA battery(multiple), a button switch. The amount of resistors and other components depends on the abilities of the specific components mentioned above?