Since I've no experience with buzzers, if there are any good ways to choose the right resistor and npn. By the way, I'm using STM32's MCU, supplied with 3V1 to drive a buzzer (GSC4417YA-16R4000).

I have designed a PCB using the ttgo t-display and other components. I have been attaching it to the PCB that you make for me. Can you install this board to my PCB so I don't have to do it later?The board you make for me is T-1K2W386046A and W386046AS1K1 Thanks. Martin Nohr

The circuit design I'm looking at is using a NAND Schmitt trigger and a p channel enhancement mode mosfet with a tactile switch. What are the benefits of that?

Hi all, I need to control the speed of a handful of small pumps independently. The speed is directly related to the voltage supplied. I can't really use pwm and the voltage to the pumps must vary between 3 and 12 volts. I'm thinking something like a buck converter with some kind of signal input to change the output. Ibelieve there must be ...

How can I avoid adding the three plus signs, shown, that are not part of my design? What are they called? I'm using Ultiboard.

How to find out price of PCB depending on BGA pad diameter? Online calculator do not have this parameter.

It is always seen that audio amplifier work at fixed gain, while attenuating the signal at the input to change the volume. That doesn't sound good since you decrease signal to noise ratio. Also reducing the gain by acting on the feedback network should improve linearity at lower gain. But why no one ever does this?

I plan to put solder on a corner pad, place the chip and solder that pin, then do the rest one by one. The problem I foresee is that it's almost impossible to see bridged pins because they're mostly under the chip. I will check continuity on pins before soldering then after to help troubleshoot this potential issue. And the pin spacing is 1...

Why does an inductor cause current to lag voltage? Doesn't a conductor need to have current running through it while it is passed through a magnetic field to produce an opposing EMF?

I'm building something with an arduino nano which uses 8 buttons (digital) and 8 potentiometers (analog). I would like to add more inputs to the build, but need to be able to use multiple inputs at once.I have enough inputs for the current features, but is there any way to add more whilst still being able to manipulate more than 1 at once?