6
votes
I don't know if my connections are correct. (Schematic to breadboard)
The "black input line" (Labeled "-" on your breadboard) should connect directly to four components, but I only count three.
Trick is this: while a solderless breadboard cannot be ...
- 100k
5
votes
What do the dashed lines between the contacts mean? What does ON & OFF mean here?
What does the dashed lines between the contacts mean?
The dashed line means that the contacts are mechanically linked.
what does ON & OFF mean here?
When the button is pushed the contacts close ...
- 473k
4
votes
I don't know if my connections are correct. (Schematic to breadboard)
This is the circuit you have created on breadboard:
simulate this circuit – Schematic created using CircuitLab
Which probably could be drawn better but it gives me a 404 error when I try to ...
- 12.2k
3
votes
What is the purpose of the relay and transistor in this circuit?
Goodness, that schematic is a shambolic hot mess. Vcc and GND are reversed on the OLED vs. ESP32.
I suppose the 7805 is supposed to reduce 9V to 5V and the ESP32 module provides the 3.3V as an output.
...
3
votes
What is the purpose of the relay and transistor in this circuit?
At the very least I think the relay is drawn backwards. It should be mirrored horizontally.
The purpose of the transistor is to provide higher current for the D23 signal from the ESP32 to drive the ...
- 206
3
votes
I don't know if my connections are correct. (Schematic to breadboard)
Figure 1. First error.
simulate this circuit – Schematic created using CircuitLab
Figure 2. What you have made.
There are no component designators on your breadboard layout so I don't know ...
- 180k
1
vote
Can I replace the big crystal oscillator with a smaller oscillator (in size) in MCP2515?
You need to look at the same parameters the existing crystal tells you. Or look at what chip data sheet tells about what kind of crystals it requires or works best with.
If you intend to only replace ...
- 172k
1
vote
Is this a good design for having 2 power inputs for a PCB?
Yes the datasheet explicitly warns about spikes when hotplugging like USB. Even one meter and shorter cables have inductance. It is best to put protection than to damage the device.
There is no ...
- 172k
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