Please tell me how to write the gnd line in the ± power supply circuit.
I am attaching the schematic and auto-wired diagram.
Your auto-wired has placed gnd lines.
Your auto-wired has also shorted all the pads on all the transistors.
PCB will not work.
Thank you for your reply.
I am very grateful to you.
This automatic wiring is fine for the ground line.
Looking at the auto-routed diagram, it looks like all the pads of the transistor are stuck together.
Is this a short circuit?
So how do we avoid short circuits?
Thank you.
Well for a couple of transistors you have connected the collector to base. Q2 looks like a current mirror so may be legitimate. Not sure about Q13. If your schematic is wrong, the PCB will be faithfully wrong too.
Also be careful of junction dots. They are actual connections. If the wire isn’t joined but just crosses there will be no junction dot.
Yes they are joined/overlapping on the PCB. Yes they are short circuited… all of them.
Where did you find the transistor footprints?
I have to agree with @retiredfeline . I’m not at all sure about the schematic.
Q13 is also a current mirror and provides the base voltage for Q8 and Q3. The Base-Emitter voltage has a strong temperature coefficient (-2mV/K just like a diode) and temperature differences will result in different currents for such a current mirror.
There are several suspicious area’s on the schematic though.
Be wary of any part where a connection does not look “clean”.
Below I’ve posted two screenshots of such areas. The basis of both these transistors have spurious wire connections.
This looks like a straight copy from the datasheet of the NJM4850 opamp (See title block). On a single die the transistors are much better matched, and they also always have (very nearly) the same temperature.
With no output connector?
Thank you for your reply.
I am very grateful to you.
When I enlarged the PCB editor and checked it, I was able to confirm the connection between the collector and the base of Q2 and Q13.
When I checked the junction dots, there is no junction dot in the PCB editor, but I checked the connection with the pad.
Thank you.
I zoomed in on the PCB editor to see if the drill holes and annular ring weren’t touching.
There is a line around the annular ring, but it seems that it is only touching.
It doesn’t look like it’s shorted, but is it?
The transistor in the footprint assignment tool is
“Package_TO_SOT_THT: TO-92_Inline”.
This is the equivalent circuit diagram of NJM4580DD.
The output is resistor R13 and is dropped to GND.
A sine wave with twice the voltage of the sine wave input to Q5,
I am trying to see if I can observe it with an oscilloscope with R13.
I realized that. I was surprised there was no output terminal on the PCB.
The best I can determine with the uploaded image, but your PCB Editor may show differently.
Thank you for your reply.
I am very grateful to you.
This is the equivalent circuit diagram of NJM4580DD.
The output is resistor R13 and is dropped to GND.
A sine wave with twice the voltage of the sine wave input to Q5,
I am experimenting with R13 to see if it can be observed with an oscilloscope.
Of course I know it won’t work.
First of all, I plan to design and try it with Kicad like the equivalent circuit diagram of NJM4580DD.
Thank you.
The output terminal is a totem pole output from a push-pull circuit, and is dropped to GND by preparing a resistor R13 as a load.
I’ve zoomed in on the PCB editor, so I think the circuit works.
Could there be a mistake that I am unaware of?
Sorry, I’m not sure with the PCB. The layout is extremely difficult to read.
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Thank you very much!
Done.
Thank you everyone.
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